Al's Annual Inspection Thread 2015

[Al Skierkiewicz]

OK, it is that time again so I will start here with Bumpers (Yes, I have had several teams report that they intend to add bumpers this year).

Yes, you can add bumpers this year but they are entirely optional and...
1. They must be weighed as part of the robot weight, and that total cannot exceed 120 Lbs, R4.
2. The bumpers when attached must also fit in the TRANSPORT CONFIGURATION R3.
3. Bumper construction will be inspected for potential safety hazards and attachments like any other robot parts.
3. As bumpers are entirely optional, they do not need to cover specific areas of the frame perimeter.
4. Bumpers do not need to be constructed as suggested in the Bumper Design Guide found here (http://www.chiefdelphi.com/forums/www3.usfirst.org/sites/default/files/uploadedImages/Robotics_Programs/FRC/Resources/2015_Bumper_Design_Guide.pdf). Be aware that the guide is a tried and tested design.

In addition to the rules as published, Team Updates come out on Tuesday and Friday each week. If Team Update changes or modifies a robot rule, that change will be part of the inspection process at subsequent events.

I would like to point out a Team Update was published Friday, 2/6/2015, concerning custom MXP boards. This is not a change in the rule but a clarification to make it easier to understand and flow chart is included. Restated, if you have any active components on your custom made MXP board and you are using any of the PWM outputs on the MXP connector for controlling motors or servos, the board can only be one of the three pre-approved boards listed in R58.

More to come later...

[GeeTwo]

2. The bumpers when attached must also fit in the TRANSPORT CONFIGURATION R3.
Unless you're going to install the bumpers (in under 60 seconds) once you reach the playing field.

[rich2202]

Unless you're going to install the bumpers (in under 60 seconds) once you reach the playing field.

However, they are still taken into account for Transport Configuration, wherever they are stored on the Robot.

Maybe delete "when attached" from the bullet point.

[rich2202]

I would like to point out a Team Update was published Friday, 2/6/2015, concerning custom MXP boards. ...This is not a change in the rule but a clarification to make it easier to understand and flow chart is included. Restated, if you have any active components on your custom made MXP board and you are using any of the PWM outputs on the MXP connector for controlling motors or servos, the board can only be one of the three pre-approved boards listed in R58.

More to come later...

Is a simplified interpretation: "Except for the pre-approved boards, and boards with no components (board is only line traces), No connection from the MXP board to a Motor Controller."?

Any thoughts on why Custom Circuits cannot be used for PWM, but are allowed on the CAN Bus, and thus might be controlling the Motor Controllers?

[GeeTwo]

Any thoughts on why Custom Circuits cannot be used for PWM, but are allowed on the CAN Bus, and thus might be controlling the Motor Controllers?

I believe that this is in keeping with R57:


Every relay module, servo, and PWM motor controller shall be connected to a corresponding port (relays to Relay ports, servos and PWM controllers to PWM ports) on the roboRIO or via a legal MXP connection (per R58). They shall not be controlled by signals from any other source.


As I interpret it, they are trying to ensure that when they issue the "disable" command, that they are certain that it will have that effect. This is both a safety and a game issue.

[cgmv123]

but are allowed on the CAN Bus, and thus might be controlling the Motor Controllers?

Because R59 say all motor controllers on the CAN Bus must be controlled by the RoboRIO and R62 says CUSTOM CIRCUITS or other devices that interfere with those communications are not allowed.

[Al Skierkiewicz]

Gus,
The TRANSPORT CONFIGURATION will be determined during inspection at the same time as weight. Under Tournament rule T6 there is no provision for removing bumpers to determine size limits.

T6 While transferring the ROBOT throughout the event (e.g. between the Team’s Pit, Practice Field, ARENA, Inspection Station, etc.), the ROBOT must not exceed a volume that is 28 in. wide x 42 in. long x 78 in. tall (the TRANSPORT CONFIGURATION).
(Emphasis is mine.)

Safety is our prime concern for everyone involved. As such, nothing may cause robot movement until and during the times the robot is enabled by the Field Management System.

[rich2202]

Gus,
The TRANSPORT CONFIGURATION will be determined during inspection at the same time as weight. Under Tournament rule T6 there is no provision for removing bumpers to determine size limits.


There is also no rule requiring bumpers be attached at their operating position for Transport Configuration. During TC, the bumpers could be sitting inside the robot, and on the field quickly attached with pins.

[jvriezen]

Gus,
The TRANSPORT CONFIGURATION will be determined during inspection at the same time as weight. Under Tournament rule T6 there is no provision for removing bumpers to determine size limits.

T6 While transferring the ROBOT throughout the event (e.g. between the Team’s Pit, Practice Field, ARENA, Inspection Station, etc.), the ROBOT must not exceed a volume that is 28 in. wide x 42 in. long x 78 in. tall (the TRANSPORT CONFIGURATION).
(Emphasis is mine.)


I'm not getting this Al. Why can't I remove my bumpers, store them inside the bot, and transport my bot to the practice field, arena, inspection area, etc. Check the weight & TC volume with the bumpers stored inside the bot, and then put them on if needed for additional inspection, just like I'd put any other attachment on after transporting to the inspection station. Since your quoted rules never mention the word BUMPER, how does your bumper restriction not also apply to any other attachment that must be relocated for transporting?

[Al Skierkiewicz]

John and Rich,
It is my understanding, that bumpers, if used, are part of the robot, just like an arm, a pickup device or the control system. That means that the bumpers are not considered separate of the ROBOT and all rules apply. As such, the bumpers need to be mounted on the robot for weight and size. I suppose you can (for this year only) have bumpers on moveable parts that retract the bumpers into the robot for determining the TRANSPORT CONFIGURATION. Just as in the past, if you have multiple devices that can be used on your robot, all mechanisms must be weighed together, and the overall size will need to be determined for each configuration under R4. The change in the bumper rules applies to this season. There is no telling what next season will bring.

[notmattlythgoe]

John and Rich,
It is my understanding, that bumpers, if used, are part of the robot, just like an arm, a pickup device or the control system. That means that the bumpers are not considered separate of the ROBOT and all rules apply. As such, the bumpers need to be mounted on the robot for weight and size. I suppose you can (for this year only) have bumpers on moveable parts that retract the bumpers into the robot for determining the TRANSPORT CONFIGURATION. Just as in the past, if you have multiple devices that can be used on your robot, all mechanisms must be weighed together, and the overall size will need to be determined for each configuration under R4. The change in the bumper rules applies to this season. There is no telling what next season will bring.

Al,

R3 allows for minor disassembly to be made to get the robot into its transportation configuration. This would allow them to take the bumpers off and place them somewhere on the robot inside the size constraints. Then when they get on the field they would be allowed to reattach them prior to the match.

[Jon Stratis]

Al - Is the only option retraction for bumpers? The blue box under R3 states the TRANSPORT CONFIGURATION size constraints can be met with "minor disassembly"., And references G10, which gives a guideline of 60 seconds for on field configuration. I guess the question boils down to the definition of "minor disassembly". Having a set of bumpers that can be removed and placed inside the robot for transport, then attached quickly with a couple of wing nuts seems to me to meet the intent of the rules.

[ATannahill]

Al,

I can see situations where the only time certain parts, not limited to bumpers, are mounting on the robot is outside of transportation configuration. The rules allow for pieces to be removed from the robot to make it fit in the TC. If all parts of the robot are to be attached at weighing, the robot should not be expected to be within TC. Simply put, being within the TC and having all parts attached might be mutually exclusive for some robots.

[jvriezen]

'Bumper' is not even a glossary item and as such appears to have no special distinction as compared to other attachments or robots components/assemblies/mechanisms. In fact, there is no definition of where the boundary between a bumper and a non-bumper element is. If I want to call my steel bar located in the center of my robot a bumper, there is no rule that says I can't do so, and doing so has no impact on any aspect of the rules, as near as I can tell. Heck, I can claim my RoboRio is doing double duty as my bumper.

Edit: Having said all that, there is much practical benefit to not having teams remove and attach bumpers for every match. We've seen how that works in the past for many teams, but I don't think the rules speak to the issue.

[AustinShalit]

Hi Al,
I am a bit confused. I thought that bumpers could be attached on the field as long as they go on within 60 seconds (or reasonable time) G10 & G11 and fit within the TRANSPORTATION CONFIGURATION. For example, if I have an upright on the robot (that only rises 6ft) and I use a bungie cord to temporarily secure my bumpers to that upright that is legal within the rules? Does Q&A Q189 (https://frc-qa.usfirst.org/Question/189/the-blue-box-by-r3-says-we-can-have-additional-aids-such-as-bungee-cords-to-get-the-robot-into-transport-configuration-would-this-also-include-removable-metals-pins-or-ratchet-straps-may-these-onl) say that that bungie cord would not count against the total robot weight?

Thanks,
Austin

[JamesCH95]

I have a specific pneumatics question - can air cylinders be plumbed with no control valving (solenoid or otherwise)? I.e. always pressurized in a given configuration so they act as a constant-force spring.

Related to bumpers - I wouldn't even call them "bumpers" anymore, as that term is associated with a part or parts subjected to specific rules and exempt from volume and weight rules. Bumpers, as in BUMPERS specifically defined by the manual, do not exist in this year's game.

[AustinShalit]

I have a specific pneumatics question - can air cylinders be plumbed with no control valving (solenoid or otherwise)? I.e. always pressurized in a given configuration so they act as a constant-force spring.

This is a good question, my 2 cents is that it will be ok as long as it matches the diagram in R67.

[ATannahill]

I have a specific pneumatics question - can air cylinders be plumbed with no control valving (solenoid or otherwise)? I.e. always pressurized in a given configuration so they act as a constant-force spring.

Related to bumpers - I wouldn't even call them "bumpers" anymore, as that term is associated with a part or parts subjected to specific rules and exempt from volume and weight rules. Bumpers, as in BUMPERS specifically defined by the manual, do not exist in this year's game.
I would suggest you wait for your Q&A question to be answered. That will carry more weight than what is posted here.

[AustinShalit]

Related to bumpers - I wouldn't even call them "bumpers" anymore, as that term is associated with a part or parts subjected to specific rules and exempt from volume and weight rules. Bumpers, as in BUMPERS specifically defined by the manual, do not exist in this year's game.

You can call them "bumpers" but not "BUMPERS".

[Jon Stratis]

James, I'm not aware of any rules that would prohibit that, providing you meet all rules, of course (the cylinder is on the low pressure side, you have all required components for a pneumatic system, everything is properly rated, etc)

[Alan Anderson]

I have a specific pneumatics question - can air cylinders be plumbed with no control valving (solenoid or otherwise)? I.e. always pressurized in a given configuration so they act as a constant-force spring.

The answer to Q312 (https://frc-qa.usfirst.org/Question/312/under-section-4-10-rule-66-there-is-a-list-of-items-that-are-not-considered-pneumatic-devices-and-therefore-are-not-subject-to-pneumatic-rules-item-b-on-this-list-is-closed-loop-cots-pneumatic) indicates that pneumatic cylinders are always subject to the pneumatics rules. I don't see any way for a permanently-pressurized cylinder to meet those rules.

[JamesCH95]

I would suggest you wait for your Q&A question to be answered. That will carry more weight than what is posted here.

Which is precisely why I asked Q&A. However, it never hurts to forewarn/get the opinion of the in-field experts and LRIs like Al and Jon.

James, I'm not aware of any rules that would prohibit that, providing you meet all rules, of course (the cylinder is on the low pressure side, you have all required components for a pneumatic system, everything is properly rated, etc)

Thanks. This is the same conclusion I arrived at.

[JamesCH95]

The answer to Q312 (https://frc-qa.usfirst.org/Question/312/under-section-4-10-rule-66-there-is-a-list-of-items-that-are-not-considered-pneumatic-devices-and-therefore-are-not-subject-to-pneumatic-rules-item-b-on-this-list-is-closed-loop-cots-pneumatic) says that pneumatic cylinders are always subject to the pneumatics rules. I don't see any way for a permanently-pressurized cylinder to meet those rules.

Allow me to clarify then.

I am not referring to a permanently sealed or pressurized air cylinders. I just want to put 60psi into one side of an air cylinder without a solenoid valve in the way. The air will vent when the pneumatic system is de-pressurized.

[FrankJ]

So Q&A 312 refers to a cylinder plugged at both ends. You cannot vent it with the pressure release valve so that is not legal. The Q&A does not address directly plumbing the cylinder to the working pressure line.

Unless there is a rule stating cylinders must be plumbed through a control valve, I don't see how it could not be legal. (Q&A unless Q&A rules otherwise) The pressure regulator is self relieving by rule so over pressurizing the system is not an issue. Now if you where to add a couple of check valves & turned it into a air pump... But check valves are not allowed by rule. Nevermind.

On the subject of bumpers. For this year only you can put lead-iron rods in your pool noodles? :yikes:

[rich2202]

Allow me to clarify then.

I am not referring to a permanently sealed or pressurized air cylinders. I just want to put 60psi into one side of an air cylinder without a solenoid valve in the way. The air will vent when the pneumatic system is de-pressurized.

You must make sure that pressure never exceeds 60 PSI on the working side. If you are using it as a spring, the compression could increase the pressure above 60 PSI. One possible solution is to put a pressure relief valve on the working pressure side that is set to 60 PSI.

[orangemoore]

On the subject of bumpers. For this year only you can put lead-iron rods in your pool noodles? :yikes:

Are you sure it will just be for this year?
;)

[Al Skierkiewicz]

So everyone, I am in contact with HQ now over this question. Give me a day or so to straighten this out.

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

[JamesCH95]

Thanks Al!

You must make sure that pressure never exceeds 60 PSI on the working side. If you are using it as a spring, the compression could increase the pressure above 60 PSI. One possible solution is to put a pressure relief valve on the working pressure side that is set to 60 PSI.

Since this air cylinder will be connected to the main 60psi working line any excess pressure will be vented by the regulator. This configuration is key in both its operation in our design as well as keeping it legal.

[MrForbes]

It's common practice on our robots to plumb pneumatic cylinders so they are pressurized when there is system pressure, and it's also common for there to be a way to have them be "actuated" mechanically, which will increase system pressure momentarily so that the regulator will have to vent it. The only difference he is proposing, is not having a solenoid valve in the system.

[AustinShalit]

So everyone, I am in contact with HQ now over this question. Give me a day or so to straighten this out.

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

Does it move without being enabled by the FMS? If it extends when there is pressure in the system, how does that pressure get there? According to the rules the only way that pressure can get there is via "one and only one compressor" (R68) that "must be powered and controlled by the ROBOT" (R69). If this is the case then, wouldn't this actuator be controlled by the FMS? How is this any different than a solenoid that is locked in the 'on' position?

[Thad House]

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

If thats an issue with R8, wouldnt that mean that any mechanism that is run off of a single solenoid, or any mechanism that moves when air is vented be illegal at that point? We can't control gravity, which causes alot of devices to move when the robot is disabled.

[JamesCH95]

So everyone, I am in contact with HQ now over this question. Give me a day or so to straighten this out.

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

Al,

I have thought about this and I would suggest that it is no different from a typical air cylinder in most regards. It will not change state unless (a) the compressor kicks on and charges air, which only happens when enabled; or (b) the venting valve is opened, in which case ANY air cylinder could move. The only functional difference I can come up with is compared to 'one-way' solenoid valves, that default to a given state when disabled or de-powered, in which case the 'always connected' air cylinder is safer, because it doesn't change rapidly or without explicit input (venting air pressure or charging air pressure).

[rich2202]

any excess pressure will be vented by the regulator.

I would confirm that if I were you. Some regulators block all air going in the reverse direction, and do not have a way to vent excess pressure.

[JamesCH95]

I would confirm that if I were you. Some regulators block all air going in the reverse direction, and do not have a way to vent excess pressure.

The 'black Norgren' regulator specified by the pneumatic section of the manual vents excess pressure for exactly this reason.

[Thad House]

I would confirm that if I were you. Some regulators block all air going in the reverse direction, and do not have a way to vent excess pressure.

Then that regulator is not a legal regulator. According to R71 the main regulator must be a relieving regulator.

[Karthik]

John and Rich,
It is my understanding, that bumpers, if used, are part of the robot, just like an arm, a pickup device or the control system. That means that the bumpers are not considered separate of the ROBOT and all rules apply. As such, the bumpers need to be mounted on the robot for weight and size. I suppose you can (for this year only) have bumpers on moveable parts that retract the bumpers into the robot for determining the TRANSPORT CONFIGURATION. Just as in the past, if you have multiple devices that can be used on your robot, all mechanisms must be weighed together, and the overall size will need to be determined for each configuration under R4. The change in the bumper rules applies to this season. There is no telling what next season will bring.

Al,

R3 allows for minor disassembly to be made to get the robot into its transportation configuration. This would allow them to take the bumpers off and place them somewhere on the robot inside the size constraints. Then when they get on the field they would be allowed to reattach them prior to the match.

I'm very confused here. On one hand we have the game manual saying that we're allowed to perform minor disassmembly to fit into the Transportation Configuration, while on the other hand the Chief Robot Inspector for FIRST is saying that it's illegal. Normally I'd just go with the manual, but as I've been told many times on this forum the Lead Robot Inspector is the final authority at events. If there's been a rule change from what's written in the manual to disallow minor disassembly I'd like to know as soon as possible and I also would like to know why this hasn't been addressed in a Team Update.

[jvriezen]

I can't see how the GDC could suddenly declare the optional non defined bumpers to be required to be attached AND within the Transport Config at this point. I suspect a fair number of teams have quick attach/detach bumpers outside the TC that might also have integrated into them other critical mechanisms/purposes.

But I'm guessing since Al is in contact with headquarters, we'll see something about it either way on Tuesday or Friday, if not before from Al on this thread.

[FrankJ]

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

R78 (one valve to vent all pressure) essentially requires that cylinders always be ported to pressure (even if it is through a control valve) or atmosphere. enabled or disabled. Both ways would be the same violation of R8. A blocking control valve would potentially prevent this behavior but they are essentially prohibited by R78.,

[magnets]

I'm very confused here. On one hand we have the game manual saying that we're allowed to perform minor disassmembly to fit into the Transportation Configuration, while on the other hand the Chief Robot Inspector for FIRST is saying that it's illegal. Normally I'd just go with the manual, but as I've been told many times on this forum the Lead Robot Inspector is the final authority at events. If there's been a rule change from what's written in the manual to disallow minor disassembly I'd like to know as soon as possible and I also would like to know why this hasn't been addressed in a Team Update.

I have a really hard time believing that minor disassembly/assembly when on the field will be made illegal. My team, and many others (likely including yours) plan to take advantage of this unique rule this year, and have spent money/time designing and building robots that take require assembly on the field. I wouldn't say our whole strategy revolves on being able to manually install a mechanism that's considerably larger than the transport configuration, but we've spent over half our robot budget/time working on it.

We have also come in a little bit underweight, so we do plan on removable bumpers this year that are bungeed to the elevator tower when not in use, and dropped into place when the robot's on the field.

[EricH]

I'm very confused here. On one hand we have the game manual saying that we're allowed to perform minor disassmembly to fit into the Transportation Configuration, while on the other hand the Chief Robot Inspector for FIRST is saying that it's illegal. Normally I'd just go with the manual, but as I've been told many times on this forum the Lead Robot Inspector is the final authority at events. If there's been a rule change from what's written in the manual to disallow minor disassembly I'd like to know as soon as possible and I also would like to know why this hasn't been addressed in a Team Update.

I agree with Karthik. No inspector has the authority to override the Manual.*

Let me put it this way: Right now, my team is considering pinning an item or two onto our robot. Push item onto robot, push pin in, compete, remove pin, remove item and stick in robot, away we go. If minor disassembly is not allowed, we will have to add or modify a full subsystem to accomplish the same task. In one week. It would have been nice to know this, say, two weeks ago.

I also agree that we'll probably hear back either from Al or from an Update very shortly.

*If an inspector (or ref, or field staff) does override the Manual, we can usually expect a blog post in apology if it's anything like a major incident, and a Q&A clarifying if it's not a major incident.

[cadandcookies]

*If an inspector (or ref, or field staff) does override the Manual, we can usually expect a blog post in apology if it's anything like a major incident, and a Q&A clarifying if it's not a major incident.

One would hope. In some areas, however, this is not always the case. In particular last year I remember the rules regarding disabling robots temporarily outside their frame perimeters being somewhat liberally applied outside of the manual definitions, sometimes in ways that severely impacted match results.

[Foster]

So everyone, I am in contact with HQ now over this question. Give me a day or so to straighten this out.


Al asked for a day or so to get an answer on the bumpers or as some call them the BUMPERS. Can we dial back the panic until he gets back?

[Karthik]

Al asked for a day or so to get an answer on the bumpers or as some call them the BUMPERS. Can we dial back the panic until he gets back?

There are 8 days left in the build season. If this rule has been changed teams will need as much time as possible to redesign their Robots to account for the change. I don't fault anyone for panicking.

[Sperkowsky]

There's a tiny ir reciever on our robot to control the leds. During matches do you think I will be allowed just to put electric tape over it.

[EricH]

There's a tiny ir reciever on our robot to control the leds. During matches do you think I will be allowed just to put electric tape over it.

Electrical tape doesn't block IR very well. Visible light, yes. But IR isn't visible light.

I would suggest aluminum foil instead. But... I would also suggest, and probably more strongly, finding another way to control the LEDs in question.

[MrBasse]

Electrical tape doesn't block IR very well. Visible light, yes. But IR isn't visible light.

I would suggest aluminum foil instead. But... I would also suggest, and probably more strongly, finding another way to control the LEDs in question.

Whats the concern as long as it doesn't happen during a match? If you can set the LED's during the placement of the robot, wouldn't the IR be inconsequential? It's a receiver, not a transmitter, right? Why cover a receiver when you can just keep the transmitter in your pocket?

[EricH]

Why cover a receiver when you can just keep the transmitter in your pocket?

Question for you: You set the receiver, and put the transmitter in your pocket. How am I as a referee to know that you aren't triggering something if your hands wander near your pocket?


Here's the result if I do think you're triggering something: I've got my choice of G21 (if during auto), G32 (if the coach sticks it in his pocket), R84 triggering T8 (potential), T21. Almost all of which are cardable (T21 being the unknown factor, but probably a yellow for egregious behavior). That's anything from a disable to a foul+yellow to an alliance red to a yellow. Not a fun combination, should a referee decide that those lights changed because your hand brushed your pocket.

Please don't put the referees in that position. Cover it, or use something else. Use the remote stuff at demos.

[Sperkowsky]

Question for you: You set the receiver, and put the transmitter in your pocket. How am I as a referee to know that you aren't triggering something if your hands wander near your pocket?


Here's the result if I do think you're triggering something: I've got my choice of G21 (if during auto), G32 (if the coach sticks it in his pocket), R84 triggering T8 (potential), T21. Almost all of which are cardable (T21 being the unknown factor, but probably a yellow for egregious behavior). That's anything from a disable to a foul+yellow to an alliance red to a yellow. Not a fun combination, should a referee decide that those lights changed because your hand brushed your pocket.

Please don't put the referees in that position. Cover it, or use something else. Use the remote stuff at demos.
Is there a good way to quickly remove the. Receiver on and off like. Some sort of quick release connection.It's close to a pwm like cable by the looks. But honestly I don't know what it really is. I got the strip with the receiver off amazon.

[EricH]

Is there a good way to quickly remove the. Receiver on and off like. Some sort of quick release connection.It's close to a pwm like cable by the looks. But honestly I don't know what it really is. I got the strip with the receiver off amazon.

I guess the first question would be: Do the LEDs work without the receiver? The second question (because I don't want to keep you guys from using the LEDs, just find another option that's not likely to get you a penalty or other similar items if it's at all possible) would be: Can you figure out ground, signal, and the other pins?

If the LEDs will work without the receiver, I'm willing to bet that you can get some help to hook them up to another coprocessor, or the roboRIO itself. If not, my suggestion is this: You could either fasten the remote into the robot (securely), but that runs the risk of breaking a few robot rules about wireless transmission and batteries, OR put the remote on the robot cart and one or more of its batteries into your pocket (or elsewhere on the cart--this part is ideal and depends on the type of battery in question). If that latter method doesn't disable the transmitter effectively, I don't know what will--and it removes the chance of the refs thinking that you're changing the lights and thus possibly violating a bunch of rules.

[MrBasse]

Question for you: You set the receiver, and put the transmitter in your pocket. How am I as a referee to know that you aren't triggering something if your hands wander near your pocket?


Here's the result if I do think you're triggering something: I've got my choice of G21 (if during auto), G32 (if the coach sticks it in his pocket), R84 triggering T8 (potential), T21. Almost all of which are cardable (T21 being the unknown factor, but probably a yellow for egregious behavior). That's anything from a disable to a foul+yellow to an alliance red to a yellow. Not a fun combination, should a referee decide that those lights changed because your hand brushed your pocket.

Please don't put the referees in that position. Cover it, or use something else. Use the remote stuff at demos.

I can answer that question by asking another. You have a six week build time, but the robot is in a bag in your shop. How are the inspectors to know that you didn't work for 7,8, or 9 weeks? This whole system is based on a lot of trust and honesty, are we really worried about a strip of LED's in the grand scheme of things.

The other easy thing would be, if the lights change color during a match then the ref would take action. That's seems pretty open and shut to me.

[Sperkowsky]

I guess the first question would be: Do the LEDs work without the receiver? The second question (because I don't want to keep you guys from using the LEDs, just find another option that's not likely to get you a penalty or other similar items if it's at all possible) would be: Can you figure out ground, signal, and the other pins?

If the LEDs will work without the receiver, I'm willing to bet that you can get some help to hook them up to another coprocessor, or the roboRIO itself. If not, my suggestion is this: You could either fasten the remote into the robot (securely), but that runs the risk of breaking a few robot rules about wireless transmission and batteries, OR put the remote on the robot cart and one or more of its batteries into your pocket (or elsewhere on the cart--this part is ideal and depends on the type of battery in question). If that latter method doesn't disable the transmitter effectively, I don't know what will--and it removes the chance of the refs thinking that you're changing the lights and thus possibly violating a bunch of rules.
I was planning on changing the color in the pits to the color of alliance. Leaving the remote in my pit and bringing the robot to the field with electric tape over the receiver. The remote would stay far away from the bot at all times unless in the pit. I don't know whether it will work connected to the robo Rio as its a mere consumer product that I just wired up to the pdb.

[Sperkowsky]

18258

[Al Skierkiewicz]

Guys,
What I am worried about with an uncontrolled cylinder is the fact that most teams (perhaps all that use pneumatics) pressurize their robot in the pits or in queue prior to going on the field. As always, we are concerned for the safety of the teams and robots near your robot when in these areas. As I stated, on it's own there doesn't seem to be a violation of any rules. It will be inspected at any events you attend just like any other robot parts. Any regulator you use must be a relieving regulator which is intended to vent any excess pressure on the working side of the regulator.

R71 “Working” air pressure on the ROBOT must be no greater than 60 psi and must be provided through one primary adjustable, relieving, pressure regulator.

And if you ask "Have you seen any accidents or near misses with pneumatics in the pits or queue?". The answer is an emphatic "YES!!!"

I do not sit on the GDC. I make inspection decisions based on an understanding of what the GDC intent is for a particular rule. I will have an answer soon on bumpers. Please keep this in mind. If you look at the field and the number and complexity of the field objects, this will be one of those years where timing between matches is going to be dominated by field reset. I expect that G10 & G11 will be fully in force at events as I stated above.

[jwfoss]

Guys,
What I am worried about with an uncontrolled cylinder is the fact that most teams (perhaps all that use pneumatics) pressurize their robot in the pits or in queue prior to going on the field. As always, we are concerned for the safety of the teams and robots near your robot when in these areas. As I stated, on it's own there doesn't seem to be a violation of any rules. It will be inspected at any events you attend just like any other robot parts. Any regulator you use must be a relieving regulator which is intended to vent any excess pressure on the working side of the regulator.

R71 “Working” air pressure on the ROBOT must be no greater than 60 psi and must be provided through one primary adjustable, relieving, pressure regulator.

And if you ask "Have you seen any accidents or near misses with pneumatics in the pits or queue?". The answer is an emphatic "YES!!!"

I do not sit on the GDC. I make inspection decisions based on an understanding of what the GDC intent is for a particular rule. I will have an answer soon on bumpers. Please keep this in mind. If you look at the field and the number and complexity of the field objects, this will be one of those years where timing between matches is going to be dominated by field reset. I expect that G10 & G11 will be fully in force at events as I stated above.

I fail to see how this is any different from any other pneumatic cylinder connected to a solenoid valve. With or without the solenoid the cylinder will either default open or closed. The difference is that it will be a passive mechanism during operation rather than active. Obviously care must be taken when energizing the system regardless.

[Al Skierkiewicz]

There is no difference, it will still be inspected for pneumatic rules and safety.

[notmattlythgoe]

So everyone, I am in contact with HQ now over this question. Give me a day or so to straighten this out.

James, while there is no pneumatic rule that this violates what you will have is essentially a device that moves on it's own without being enabled by the FMS. Potentially that could be a violation of R8.

Al,

Thank you for looking into this, we appreciate the extra effort you put in to inform the CD community every year.

[JamesCH95]

Q&A got back to my question here (https://frc-qa.usfirst.org/Question/340/must-air-cylinders-be-controlled-by-a-solenoid-valve-or-can-air-cylinders-be-used-in-such-a-manor-where-they-are-always-charged-in-a-specific-state-i-e-used-as-a-constant-force-spring-without-any).

Sounds like we'll be set to go, assuming all pneumatic system rules are met.

[Drakxii]

I was planning on changing the color in the pits to the color of alliance. Leaving the remote in my pit and bringing the robot to the field with electric tape over the receiver. The remote would stay far away from the bot at all times unless in the pit. I don't know whether it will work connected to the robo Rio as its a mere consumer product that I just wired up to the pdb.

I would cut the receiver cable in half and crimp on quick disconnect connectors on each end. This way once the lights are set you can remove the receiver and so no commutation can happen mid game.

Now quick question, if you power down the LEDs do they remember their color? If not, I wouldn't recommend this method as you will burn battery while in line just for your lights.

Also if the goal is just alliance colors, you can just hard wire the black(power) wire of the LEDs to the PDB and then wire the blue and red wires (grounds) to a switch and then the switch to PDB. So the lights would be red or blue based on the switch.

[JamesBrown]

Question for you: You set the receiver, and put the transmitter in your pocket. How am I as a referee to know that you aren't triggering something if your hands wander near your pocket?


Here's the result if I do think you're triggering something: I've got my choice of G21 (if during auto), G32 (if the coach sticks it in his pocket), R84 triggering T8 (potential), T21. Almost all of which are cardable (T21 being the unknown factor, but probably a yellow for egregious behavior). That's anything from a disable to a foul+yellow to an alliance red to a yellow. Not a fun combination, should a referee decide that those lights changed because your hand brushed your pocket.

Please don't put the referees in that position. Cover it, or use something else. Use the remote stuff at demos.

Come on, This is pretty ridiculous. Every robot that uses vision would be capable of receiving communication from drivers in this manner. Surely you would not be suspicious of every team that has a camera. Unless you have specific reason to believe that a team is actively controlling their robot illegally during autonomous then I would hope you would not be considering penalties or cards. You are grasping at straws. If a team wanted to communicate in autonomous there are many more reliable, and more discrete ways than a remote control in autonomous. Unless you are equally suspicious of every team that has a camera that even instantaneously looks at the drivers station area, then you are being extremely unnecessarily judgmental here.

[notmattlythgoe]

Come on, This is pretty ridiculous. Every robot that uses vision would be capable of receiving communication from drivers in this manner. Surely you would not be suspicious of every team that has a camera. Unless you have specific reason to believe that a team is actively controlling their robot illegally during autonomous then I would hope you would not be considering penalties or cards. You are grasping at straws. If a team wanted to communicate in autonomous there are many more reliable, and more discrete ways than a remote control in autonomous. Unless you are equally suspicious of every team that has a camera that even instantaneously looks at the drivers station area, then you are being extremely unnecessarily judgmental here.

There is actually nothing illegal about sending signals to the robot during autonomous. As long as there is no device on the driver station itself doing it. There was actually a QA about it.

Edit: THIS IS NOT TRUE.

[Ether]

There was actually a QA about it.

Link please.

[notmattlythgoe]

Link please.




Apologies, I must have misread something. G21 prohibits any indirect interaction with the robot.

This would then be illegal.

Thank you for the check Ether.

[JamesCH95]

Come on, This is pretty ridiculous. Every robot that uses vision would be capable of receiving communication from drivers in this manner. Surely you would not be suspicious of every team that has a camera. Unless you have specific reason to believe that a team is actively controlling their robot illegally during autonomous then I would hope you would not be considering penalties or cards. You are grasping at straws. If a team wanted to communicate in autonomous there are many more reliable, and more discrete ways than a remote control in autonomous. Unless you are equally suspicious of every team that has a camera that even instantaneously looks at the drivers station area, then you are being extremely unnecessarily judgmental here.

I would bet that an IR remote is a lot easier to implement than gesture recognition from a camera located on the robot, viewing through the player station or picking out someone in the crowd.

Viewed a different way - an IR remote has no functional value to any team at competition whereas a camera does. With a camera the risk of cheating is worth the added functionality that many teams gain, whereas the risk of cheating with an IR remote is not worth the ability to turn decorative LEDs on and off.

To take your hyperbole-ridden example even further: wifi security is never 100% secure! We should make all of the robots drive around on tethered connections. Obviously this is totally impractical, at some point we must assume some risk because it is worth the reward. I can very clearly see why an IR remote would be disallowed and why cameras are allowed.

[Sperkowsky]

I would cut the receiver cable in half and crimp on quick disconnect connectors on each end. This way once the lights are set you can remove the receiver and so no commutation can happen mid game.

Now quick question, if you power down the LEDs do they remember their color? If not, I wouldn't recommend this method as you will burn battery while in line just for your lights.

Also if the goal is just alliance colors, you can just hard wire the black(power) wire of the LEDs to the PDB and then wire the blue and red wires (grounds) to a switch and then the switch to PDB. So the lights would be red or blue based on the switch.
Quick release as in a pwm style connector.

[Al Skierkiewicz]

OK,
Here it is...
I screwed up. As people have pointed out earlier in this thread, objects that fit within the 28" x 42" x 78" high size limitation are legally within the TRANSPORT CONFIGURATION even when the team intends to attach those parts to the robot on the field. Inspection will likely check your TRANSPORT CONFIGURATION as defined in T6 & R3, when checking that all of your robot (and additional mechanisms) is weighed.
To remind everyone, bumpers are not BUMPERS and only 2015 rules apply. As such B&T and withholding are affected as well.
I am very sorry for any additional ulceration this may have caused.

[Al Skierkiewicz]

As to IR devices on the robot, this seems to be the defining rule.

R52 No form of wireless communication shall be used to communicate to, from, or within the ROBOT, except those required per R46 and R51 (e.g. radio modems from previous FIRST competitions and Bluetooth devices are not permitted on the ROBOT during competition).

[Foster]

OK,
Here it is...
I screwed up.

I am very sorry for any additional ulceration this may have caused.

No problem, all of the East Coast people were looking for a scapegoat for all the snow. West Coast was looking for one for all the rain. Thanks for stepping up and checking, it takes a big CRI to say they were wrong. :)

[AustinShalit]

West Coast was looking for one for all the rain

Or Sunny and 80°... :cool:

[Drakxii]

Quick release as in a pwm style connector.

Was thinking connectors like this http://www.mcmaster.com/#standard-electrical-wire-terminals/=vundl2 (http://www.mcmaster.com/#standard-electrical-wire-terminals/=vundl2) should be able to find some at local store as well. Just makes sure to get the right gauge size.

[EricH]

Unless you have specific reason to believe that a team is actively controlling their robot illegally during autonomous then I would hope you would not be considering penalties or cards. You are grasping at straws. If a team wanted to communicate in autonomous there are many more reliable, and more discrete ways than a remote control in autonomous. Unless you are equally suspicious of every team that has a camera that even instantaneously looks at the drivers station area, then you are being extremely unnecessarily judgmental here.

If that team's camera is looking at--and the robot is apparently responding to--a sign the team is holding, in automode, durn right I'm gonna be suspicious!

The rules are simple: NO wireless communication to the robot except via the field wireless (or by signal placards etc. outside of automode, should you choose to use that method--but I call it more trouble than it's worth).


That being said, leaving the remote in the pits would--to me--do the trick, at least as far as on-field activity is concerned. Now the whole "wireless within the robot" part of the deal is another story. So let's see if we can get you running without the wireless, and save the wireless part of the cool factor for demos.

[MrRoboSteve]

There's a tiny ir reciever on our robot to control the leds. During matches do you think I will be allowed just to put electric tape over it.

Ever consider controlling the LEDs via the roboRIO? Alliance color is available via API:

DriverStation::Alliance DriverStation::GetAlliance()

Return the alliance that the driver station says it is on.

http://first.wpi.edu/FRC/roborio/release/docs/cpp/classDriverStation.html#ab1d20060a7ca1d4d759b72988 3ce9855

Positives: no dispute with inspectors, always tracks color correctly.

[Sperkowsky]

This was my solution. I just soldered on some pwm connections. This way we can change the leds in the pit by attaching the ir putting on the robot changing the color then taking the ir receiver off. It takes about 11 seconds.


18278

[Al Skierkiewicz]

OK Round 2.
1. With the new control system there will be a need to see all of the components. Please don't hide the RoboRio, PDP and other modules. Inspectors need to see the breakers and the wires that attach to them. Field people need to see all indicators including the radio.
2. Speaking of the radio, if you want reliable operation, be sure to secure the power connector on the radio. A piece of tape works OK but a adhesive backed anchor for a wire tie works best. Either place the anchor on the radio or on your robot near the radio mounting point. If the power connector moves a lot during operation, noise is introduced to the radio power.
3. The radio works best when mounted in the clear on your robot. When you surround the radio with metal it tends to block the antennas inside the box and/or detune them to the point that your connection and bandwidth are affected.
4. The Ethernet connections to your radio should also be secure and mindful of the minimum bend radius of the cable you use. In most cases that is two inches minimum radius. When you bend the cable, bad things happen to bandwidth and the wires can be forced to migrate through their insulation.
5. All teams must connect the CAN buss from RoboRio to the PDP even if you do not use CAN or pneumatics. This connection will be used to log PDP voltage. (R61 & R62)
6. Don't forget the Robot Signal Light. At least one RSL must be mounted on the robot and visible when standing three feet in front of your robot. R54

[rich2202]

1. With the new control system there will be a need to see all of the components. Please don't hide the RoboRio, PDP and other modules. Inspectors need to see the breakers and the wires that attach to them. Field people need to see all indicators including the radio.


My team has most of the wires in wire channels. Will the RI's be following wires, or just see their connections?

[Whippet]

My team has most of the wires in wire channels. Will the RI's be following wires, or just see their connections?

My thoughts are that they are looking for proper gauge wire going to the correct breaker sizes.

[Jon Stratis]

We usually don't follow wires for their entire length. It's important that we can tell the gauge of the wires, however, and ensure other rules are being met (for example, R42). So make sure we can see an inch or two of the wire on either end, that wire gauge marks are visible if we need to double check them (sometimes your eyes play tricks on you, and you need to read the markings to make sure it's legal).

[Alan Anderson]

My team has most of the wires in wire channels. Will the RI's be following wires, or just see their connections?

The proper connection of certain wires will be important to verify: roboRIO, VRM, PCM, and bridge power; CAN from the roboRIO to the PDP; and a couple of other things specified by the rules. Aside from that, it's not the job of a Robot Inspector to verify that you have wired your robot so that it will work the way you want it to. They'll mostly be looking for correct colors and appropriate wire gauge.

[Rosiebotboss]

If I can add my .02

We're aren't necessarily looking to make sure you wire your compenents correctly to make them work, that's your job, we need to see potential hazards, chafing points, etc...

Also, when mounting the radio, the best orientation is horizontal, due to antennae "radiating" out in a "dome." If you are mounting sideways or vertical , the "dome" will be facing one way, decreasing reception.

Sorry for the non technical terms, I"m a nuts and bolts guy. Al's the antennae guy.

[Wayne Doenges]

2. Speaking of the radio, if you want reliable operation, be sure to secure the power connector on the radio. A piece of tape works OK but a adhesive backed anchor for a wire tie works best. Either place the anchor on the radio or on your robot near the radio mounting point. If the power connector moves a lot during operation, noise is introduced to the radio power.


Two words: Hot Glue!
We have never had a plug pop out or any kind of intermiitent failure

[BrendanB]

Two words: Hot Glue!
We have never had a plug pop out or any kind of intermiitent failure

I thought hot glue was brought up by Al as illegal when it was discussed before the 2014 season.

[IndySam]

We have always mounted our radio verticaly and have never had a connection problem but we have also always mounted it up high and unobstructed away from motors and other electronics.

Also a strip of gaffers tape keeps the connecton snug.

[Alan Anderson]

I thought hot glue was brought up by Al as illegal when it was discussed before the 2014 season.

It's been addressed in the 2015 robot manual:<R55> F. Fasteners (including adhesives) may be used to attach the device to the OPERATOR CONSOLE or ROBOT or to secure cables to the device.

[BrendanB]

It's been addressed in the 2015 robot manual:<R55> F. Fasteners (including adhesives) may be used to attach the device to the OPERATOR CONSOLE or ROBOT or to secure cables to the device.

My apologies I don't read the electrical rules as in depth as I do the mechanical/game rules.

Glad to see this change but of course it comes AFTER we leave the era of using the old style motor controllers with loose PWMs (at least for most teams).

[rich2202]

The proper connection of certain wires will be important to verify: roboRIO, VRM, PCM, and bridge power;

That's the root of my question. Do we need to verify that the roboRIO, VRM, and PCM are plugged into the correct ports on the PDP? If so, then we need to be able to follow the entire wire, not just verify that a similar looking wire is plugged into the roboRio port of the PDP.

[Al Skierkiewicz]

Hot glue is used by some teams but I really frown on it for a variety of reasons.
1. Unless the parts are near the melting temperature, the bond fails. I see that as giving a false sense of security. Others will surely write that they have had no problems, i bet I can pull more than 50% of those connectors out without difficulty.
2. Hot glue tends to migrate places you don't want it. That make the radio unrepairable for a failed power connector.
3. It is "ugly", that's all I have to say.

Others have stated what I would in response to seeing wires. However, we train our LRIs and RIs to see potential problems so that we can help you be more competitive. So while we are looking at for compliance, we are also seeing other issues. Help us help you.

[Karthik]

Hot glue is used by some teams but I really frown on it for a variety of reasons.
1. Unless the parts are near the melting temperature, the bond fails. I see that as giving a false sense of security. Others will surely write that they have had no problems, i bet I can pull more than 50% of those connectors out without difficulty.
2. Hot glue tends to migrate places you don't want it. That make the radio unrepairable for a failed power connector.
3. It is "ugly", that's all I have to say.


Since we're just tossing around anecdotal evidence here, Team 1114 has used hot glue extensively over the years it was legal with no failures. It's a practice we recommend to all of our partners and teams we work with.

[compsuppjk]

Also, when mounting the radio, the best orientation is horizontal, due to antennae "radiating" out in a "dome." If you are mounting sideways or vertical , the "dome" will be facing one way, decreasing reception.


Due to the nature of how MIMO and multipath radios work, particularly with the geometry of the field (read: end walls), the orientation (vertical vs. horizontal) of the radio doesn't seem to matter too much (especially as the radios are almost constantly moving anyway).

What is important, as Dana suggested, is that the radio is mounted clear of metal or other 5 Ghz RF-opaque objects, which on most robots, is typically higher up. It's also possible that noise introduced by being in extreme proximity to motors may be a factor, however, keeping clear of large, plate-like structures of metal would be my #1 priority.

[buchanan]

We usually don't follow wires for their entire length. It's important that we can tell the gauge of the wires, however, and ensure other rules are being met (for example, R42). So make sure we can see an inch or two of the wire on either end, that wire gauge marks are visible if we need to double check them (sometimes your eyes play tricks on you, and you need to read the markings to make sure it's legal).

We've had a hard time locally sourcing 12AWG wire with sufficient flexibility (high strand count) for our application. We've found 12/3 SJOOW cord whose conductors are perfect if we remove the outer jacket. Unfortunately the outer jacket is the only place that carries the AWG markings. The rules specify AWG but don't explicitly require marking. I know it makes the inspector's life easier, though. Is there a reasonable alternative, such as having a sample of the full un-separated cord on hand during inspection, or are AWG markings on the wire as seen on the robot effectively a requirement?

[JamesCH95]

We've had a hard time locally sourcing 12AWG wire with sufficient flexibility (high strand count) for our application. We've found 12/3 SJOOW cord whose conductors are perfect if we remove the outer jacket. Unfortunately the outer jacket is the only place that carries the AWG markings. The rules specify AWG but don't explicitly require marking. I know it makes the inspector's life easier, though. Is there a reasonable alternative, such as having a sample of the full un-separated cord on hand during inspection, or are AWG markings on the wire as seen on the robot effectively a requirement?

Bring a sample of the wire.

[Jon Stratis]

We've had a hard time locally sourcing 12AWG wire with sufficient flexibility (high strand count) for our application. We've found 12/3 SJOOW cord whose conductors are perfect if we remove the outer jacket. Unfortunately the outer jacket is the only place that carries the AWG markings. The rules specify AWG but don't explicitly require marking. I know it makes the inspector's life easier, though. Is there a reasonable alternative, such as having a sample of the full un-separated cord on hand during inspection, or are AWG markings on the wire as seen on the robot effectively a requirement?

It's not as rare as you may think to come across wire with no markings on it. I see it probably every year. Just keep in mind that it's the team's responsibility to prove to the inspector that the wire is the correct gauge. There are multiple ways to do this - have the original spool of wire available with clear markings on the spool itself. Have a same of the wire with the outer sheath you describe with clear markings on the branch. Have some wire strippers with fixed-sized, unmodified stripping locations (Something like this, for example (http://www.amazon.com/gp/aw/d/B00AZWWY2K/ref=mp_s_a_1_3?qid=1423671692&sr=8-3&keywords=wire+strippers&pi=AC_SX200_QL40&dpPl=1&dpID=41OkDxY0hXL&ref=plSrch)), and show the correct gauge strips the wire correctly.

Just make sure you can show that the wire is the correct gauge!

[MrRoboSteve]

It's not an unusual issue, even for experienced teams.

I was inspecting the wiring from our CIM motors back to the speed controllers, and asked whether they had looked at the wiring table. Turns out they matched the wire off of the CIMs, rather than using the table. Fixing it is now on our punch list.

[JamesCH95]

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

http://team358.org/files/pneumatic/Compressor2011.jpg

[ATannahill]

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

http://team358.org/files/pneumatic/Compressor2011.jpg



The pressure relief valve must be attached to the compressor with legal hard (non tube) fittings, so if you chose to install the NPT to plastic plug fitting, it must be past the pressure relief valve.

The relief valve must be attached directly to the compressor or attached by legal hard fittings (e.g. brass, nylon, etc.) connectedto the compressor output port. If using an off-board compressor, an additional relief valve must be included on the ROBOT.

[MrBasse]

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?

It is the compressor's fitting that typically comes with a plastic plug in it, seen here:

http://team358.org/files/pneumatic/Compressor2011.jpg

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

[ATannahill]

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

I believe that modification is legal under R65-C since it is pre-existing threads.

[JamesCH95]

The pressure relief valve must be attached to the compressor with legal hard (non tube) fittings, so if you chose to install the NPT to plastic plug fitting, it must be past the pressure relief valve.

True... but irrelevant to my question.

It comes installed, so you would have to take it off. That sounds like modification to me.

Why don't you want it? It doesn't add much weight, and it gives you an easy adaptation to a tee fitting for the relief valve.

Removing a pre-installed fitting would be like changing the terminal screws on a Victor. Yeah, it's not precisely the original hardware, but from a safety and function perspective it hasn't changed.

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The port in the compressor is 1/8NPT, so attaching normal hard-fittings and tees is the same as attaching to the steel part, it just fits into our robot a bit more easily.

[MrBasse]

It's not an unusual issue, even for experienced teams.

I was inspecting the wiring from our CIM motors back to the speed controllers, and asked whether they had looked at the wiring table. Turns out they matched the wire off of the CIMs, rather than using the table. Fixing it is now on our punch list.

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG? Are we trying to say that the manufacturer is not using the proper wire? A CIM on a 40 AMP breaker will draw a good amount of current if you tell it to, but why doesn't the CIM wiring dictate what wire is used between the breaker and the speed control?

How does it make sense that I would have to crimp 12 AWG wire to 14 AWG wire after the speed controller to be legal? How does that help?

[MrBasse]

True... but irrelevant to my question.



Removing a pre-installed fitting would be like changing the terminal screws on a Victor. Yeah, it's not precisely the original hardware, but from a safety and function perspective it hasn't changed.

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The port in the compressor is 1/8NPT, so attaching normal hard-fittings and tees is the same as attaching to the steel part, it just fits into our robot a bit more easily.

I guess I would counter by saying that you can modify electronics practically all you want. Pneumatics have painful rules in place to prevent accidents that may happen when people don't understand a system.

R65 C might give you a little leeway with that idea though since you are using the existing threads.

[JamesCH95]

I guess I would counter by saying that you can modify electronics practically all you want. Pneumatics have painful rules in place to prevent accidents that may happen when people don't understand a system.

R65 C might give you a little leeway with that idea though since you are using the existing threads.

Are you sure about that? See R55.

R65-C is why I assume our actions are legal, but I just want to double-check with the in-field experts.

[rich2202]

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG?

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

[cgmv123]

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG? Are we trying to say that the manufacturer is not using the proper wire? A CIM on a 40 AMP breaker will draw a good amount of current if you tell it to, but why doesn't the CIM wiring dictate what wire is used between the breaker and the speed control?

How does it make sense that I would have to crimp 12 AWG wire to 14 AWG wire after the speed controller to be legal? How does that help?

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

CIM wire leads also have insulation that can take more heat than the insulation that's on most wires.

[rich2202]

Another pneumatic system question: does the steel NPT fitting, standard on the Viair compressors, need to be installed?


I think "installed" is the key word. R65 says the original condition. "optional" parts are not part of the original condition.

Now, if it came with it installed, then the question is whether R65-C applies since you would be "disassembling" to remove the NPT fitting, and not "assembling".

[rich2202]

CIM wire leads also have insulation that can take more heat than the insulation that's on most wires.

Another thought:

FIRST doesn't want you replacing wires that were not intended to be replaced. Thus the concession granting exception to using wire as supplied by the manufacturer.

[Jon Stratis]

The steel coupler pushes a few fittings and a gauge to a spot that's less accessible (and makes the gauge less readable) so it is handy to not have it in place.

The only part that is required to be connected by hard fittings is the relief valve. Hook up a T with a relief valve on it, then use some tubing to located the gagged and switch and such someplace more accessible.

[scca229]

Because you put it on a circuit capable of feeding 40 amps. The RI looks at the PDB and breakers. If you put a 40 amp breaker in the PDB, then that connection has to have 12 AWG wire. The RI doesn't have to follow the circuit to see what it is connected to.

Just to verify:

PDB <-> 40A Breaker <-> 12AWG wire <-> Victor <-> 14AWG wire directly attached to CIM

Legal?

[JamesCH95]

I think "installed" is the key word. R65 says the original condition. "optional" parts are not part of the original condition.

Now, if it came with it installed, then the question is whether R65-C applies since you would be "disassembling" to remove the NPT fitting, and not "assembling".

Bingo.

[MrForbes]

Just to verify:

PDB <-> 40A Breaker <-> 12AWG wire <-> Victor <-> 14AWG wire directly attached to CIM

Legal?

As I understand it, this is legal. You can also add a length of 12 AWG wire between the Victor and the 14 AWG wire.

[Al Skierkiewicz]

So let me cover both issues here, starting with the wire.
CIM motors have a slightly higher temperature insulation and in practice would be wired to a long length of wire. (They were originally designed for trailer tongue positioners as I remember.) In our application, you can run #10 to them if you so desire. The short length of higher temp wire still keeps them safe for our purposes.
The output port of the compressor is supplied with a check valve to prevent system pressure from bleeding through the compressor. I haven't examined one in a while so I don't remember if that fitting is part of the check valve. I will try and check tonight before we mount the compressor (maybe).

[JamesCH95]

So let me cover both issues here, starting with the wire.
CIM motors have a slightly higher temperature insulation and in practice would be wired to a long length of wire. (They were originally designed for trailer tongue positioners as I remember.) In our application, you can run #10 to them if you so desire. The short length of higher temp wire still keeps them safe for our purposes.
The output port of the compressor is supplied with a check valve to prevent system pressure from bleeding through the compressor. I haven't examined one in a while so I don't remember if that fitting is part of the check valve. I will try and check tonight before we mount the compressor (maybe).

Thanks!

[Jon Stratis]

I know one of their different compressors, the 250c IG variant utilizes a completely separate check valve that has to be installed to work.

[FrankJ]

I might be missing something really simple, but I never understood this rule. If the device in question has 14 AWG wire standard, why do I have to feed it with 12 AWG? Are we trying to say that the manufacturer is not using the proper wire? A CIM on a 40 AMP breaker will draw a good amount of current if you tell it to, but why doesn't the CIM wiring dictate what wire is used between the breaker and the speed control?

How does it make sense that I would have to crimp 12 AWG wire to 14 AWG wire after the speed controller to be legal? How does that help?

Just be really happy First doesn't make you take apart the motor and solder 12 AWG wires to it. :eek: In the integral HP world, the feed wires are always bigger than the wires in the motor. The manufacturer can make an engineering judgment on how big the wires need to be based on more known factors than the general case of power distribution wiring.

[Mr V]

Circuit breakers are circuit protection devices, that means they exist to protect the wire. What they protect the wire from is the insulation getting so hot it melts. There are many types of insulation with many different melting points and the rating for the wire and insulation is dependent on the conditions it is used in. That means there is no universal rating for say a 12ga wire. The CIM wires enter the motor where the temps will be much higher than ambient. Because of that they use high temp insulation which means that particular 14ga wire can safely carry a 40a load.

It is not practical for all inspectors to be trained to identify all types of insulation, know their temp ratings and to have to check the type of insulation on a robot by robot basis. So FIRST makes the assumption that a motor MFG knows what they are doing when they selected the attached wire and that the average team will be using wire with low temp insulation and set the rules accordingly.

[Wayne Doenges]

Several other things that get missed when building our bots.
1) Please allow easy access to the 120 amp breaker. No one wants to see their bot burn because the ref couldn't find the breaker.
2) The same for the pneumatic vent. Don't hide it.
3) Sharp corners. I don't like to see blood, espaeiclly my own :ahh:
4) If you are using pneumatics, please have the guages where we can see them.

[Al Skierkiewicz]

James,
I checked our ViAir last night and the check valve is mounted directly to the compressor. It has a nice arrow punched into the body. The additional fitting appears to the transition for supplied check valve. I did not pull ours apart to see what, or if, there is a threaded transition on the check valve. This is certainly a question for the Q&A I think. I like that there is some metal at that port to help cool off the output air. That little compressor does run hot if you run it often.

[Richard Wallace]

I know one of their different compressors, the 250c IG variant utilizes a completely separate check valve that has to be installed to work.I see that your team has asked the GDC (Q360) if the check valve supplied with Viair model 250C-IG compressor is legal.

If that check valve is considered a part of the compressor, then NOT using it would violate R65. If it is considered a separate part, then using it would violate R66.

Based on the GDC's response to 2014 Q325, I think the hose AND the check valve that come from the manufacturer should be considered parts of the compressor, and therefore required per R65. Of course my opinion is worthless at inspection.

Eagerly awaiting the GDC's word on 2015 Q360. :)

[Jon Stratis]

I see that your team has asked the GDC (Q360) if the check valve supplied with Viair model 250C-IG compressor is legal.

If that check valve is considered a part of the compressor, then NOT using it would violate R65. If it is considered a separate part, then using it would violate R66.

Based on the GDC's response to 2014 Q325, I think the hose AND the check valve that come from the manufacturer should be considered parts of the compressor, and therefore required per R65. Of course my opinion is worthless at inspection.

Eagerly awaiting the GDC's word on 2015 Q360. :)

Yup, that was me asking... I saw them answer a question that check valves are illegal (which was expected), but wanted to make sure there was another answer directly applicable to the compressor we're using so an overzealous inspector didn't point to that Q&A and make our whole system worthless. I can't overturn inspectors when dealing with my own team :)

[FrankJ]

I know one of their different compressors, the 250c IG variant utilizes a completely separate check valve that has to be installed to work.

All the First legal compressors have two check valves in them. One on the inlet, one on the outlet. Without them, the compressor essentially becomes a cylinder mounted to a motor.

[JamesCH95]

James,
I checked our ViAir last night and the check valve is mounted directly to the compressor. It has a nice arrow punched into the body. The additional fitting appears to the transition for supplied check valve. I did not pull ours apart to see what, or if, there is a threaded transition on the check valve. This is certainly a question for the Q&A I think. I like that there is some metal at that port to help cool off the output air. That little compressor does run hot if you run it often.

Thanks Al, will submit a Q&A.

FWIW we have mounted numerous 'hard' brass fittings to the compressor outlet to aid in cooling off the compressed air.

Edit: Q&A here - https://frc-qa.usfirst.org/Question/366/the-viair-90-compressor-has-a-steel-fitting-that-comes-installed-in-preexisting-threads-1-8in-npt-it-can-be-seen-here-http-www-andymark-com-product-p-am-2005-htm-must-this-steel-fitting-remain

[Jon Stratis]

All the First legal compressors have two check valves in them. One on the inlet, one on the outlet. Without them, the compressor essentially becomes a cylinder mounted to a motor.

Right, check valves are pretty necessary for a compressor, but most of them have it "built in". The 250C IG has it attached to the required leader hose, and it's real easy for it to be viewed by an inspector as a separate part.

[FrankJ]

Right, check valves are pretty necessary for a compressor, but most of them have it "built in". The 250C IG has it attached to the required leader hose, and it's real easy for it to be viewed by an inspector as a separate part.

I understand. :)

From a functionality point of view he check valve needs to be attached directly to the compressor to keep the compression ratio as high as possible. The braided hose there to keep people from attaching plastic hose directly to the compressor which can be hot enough to cause the plastic hose to fail.

[FrankJ]

While not formerly defined in the glossary. Bumpers are still an inspection check list item. Listed as optional. I understand why it is there since it is a considerable departure from previous years rules.

"Previous years rules do not apply to the current game." Now where have I heard that before? :]

[Al Skierkiewicz]

I understand. :)

From a functionality point of view he check valve needs to be attached directly to the compressor to keep the compression ratio as high as possible. The braided hose there to keep people from attaching plastic hose directly to the compressor which can be hot enough to cause the plastic hose to fail.

I checked on this when that compressor became an option a few years ago. The manufacturer requires it as it supplies a cooling path for the hot air. On that compressor only, as it is required by the manufacturer, the hose is considered part of the compressor and must be attached. As a note, I have only seen one in inspection.

[Toa Circuit]

Are we permitted to put a two-way manually operated tee-valve between 60 a psi source and a solenoid valve, such that in one position, the valve connects 60 psi to the solenoid input (like if it were a normal connection), and in the other position, the valve connects atmosphere/vent to the solenoid input, and blocks off the 60 psi source? (We want to be able to move some pistons by hand during setup, but don't want to evacuate our air tanks to do this.)

[Jon Stratis]

I checked on this when that compressor became an option a few years ago. The manufacturer requires it as it supplies a cooling path for the hot air. On that compressor only, as it is required by the manufacturer, the hose is considered part of the compressor and must be attached. As a note, I have only seen one in inspection.

I can guarantee you'll see another one up in Duluth this year :)

[rich2202]

two-way manually operated tee-valve

Would that be an R66F Flow control Valve?

Make sure that in either position, R78 requirement is met (vent the entire system), and
R79 (output of multiple valves) are not plumbed together (solenoid and manual valve).

[Toa Circuit]

Would that be an R66F Flow control Valve?

Make sure that in either position, R78 requirement is met (vent the entire system), and
R79 (output of multiple valves) are not plumbed together (solenoid and manual valve).

It's essentially one of these, but plastic: http://www.valworx.com/product/bronze-3-way-diverter-ball-valve-12/bronze-3-way-ball-valves-l-port?gclid=CjwKEAiAgfymBRCEhpTR8NXpx1USJAAV0dQyC8P wtRIfPl2dF-trEZyCF1PaD0PGGVB--A3YTr8utBoCiA7w_wcB

So yes, R78 is met, as well as R79 (this is a series system, not a parallel system).

[Al Skierkiewicz]

Thad,
From your description I would say the valve does not meet the intent of the rules. I would however recommend you ask the Q&A for a more definitive answer.

[Al Skierkiewicz]

While we are on the subject, the pneumatic rules haven't really changed much for many years, this year but there may be one or two gotchas...
1. Please understand the "one and only one" in R68. This means that only one compressor can supply air to the robot. If it fails you can replace it with a functional and identical one without the need to reinspect. If you have one mounted on your robot, you may not use another one to supply air for a match. That means you cannot have a compressor on your cart, in your pit or behind a curtain that you use to supply air to your robot. You may not run the compressor connected directly to a battery, ever.
2. The one compressor can be on board you robot or off board your robot. In all cases the one compressor must be controlled by the RoboRio sensing system pressure.
3. No white Clippard tanks.(P/N: AVT-PP-41)
4. The only pressure switch you may use is a Nason pressure switch, P/N SM-2B-115R/443 under R67-C. Often teams mount this near the outside of the robot, please be sure to insulate the terminals once you have connected your wiring.
5. There are several example drawings in the robot rules for your use.
6. Pneumatic parts may not be modified in any way other than the prescribed use and attachment of tubing adapters and mounting. Painting, filing, gluing, drilling, etc. are considered modifications.
7. If you are using pneumatic parts that are not normal devices, be sure to have manufacturers sheets detailing the max pressure ratings. Home made manifolds do not meet pneumatic rules under R64.
Hope you are getting close to finishing your robots. Bag day is just two days away.

[Jacob Bendicksen]

Someone asked this in the 148 reveal thread, and I'm curious, so I'm asking it here: how would a robot like 148 (https://vimeo.com/119664649)'s be inspected with regards to numbering? Seems like it's in a bit of a gray area.

[Foster]

There is another HUGE thread about numbers. Black numbers on a white background, etc. There are three parts to number, they number all three and they are done. I really don't get the mystery over the numbers, it's pretty plain and simple.

[Jacob Bendicksen]

There is another HUGE thread about numbers. Black numbers on a white background, etc. There are three parts to number, they number all three and they are done. I really don't get the mystery over the numbers, it's pretty plain and simple.

My question was more about multi-part, tethered robots like 148. I get the regular numbering rules, but when a robot has multiple almost-separate components, it could be hard for viewers to tell that they're all part of the same machine.

[TogetherSword8]

I know your are an inspector and not a referee, but are we allowed to, during setup on the field, activate our pneumatics systems via pushing the buttons on the solenoids of our robot? I would like to start a match with our pneumatics systems out of the robot, but during transport, no pressure and with pressure, they would be fully contained within the transport configuration.

[MrRoboSteve]

I know your are an inspector and not a referee, but are we allowed to, during setup on the field, activate our pneumatics systems via pushing the buttons on the solenoids of our robot? I would like to start a match with our pneumatics systems out of the robot, but during transport, no pressure and with pressure, they would be fully contained within the transport configuration.

A good way to think about this is to find the rule that allows what you want, and think about how you might argue that what you want to do is permitted. If there's some ambiguity, use the Q&A system.

[rich2202]

In R65 (allowed changes to pnumatics), the blue box says: "Do not, for example, paint ... any part of a pneumatic".

I remember a discussion last year about no labels or writing on plastic air tanks. In theory, the ink or adhesive could weaken the tank wall.

However, R65-E allows labeling.

So, can people put stickers, or write, on the air tanks or hoses?

[rich2202]

At a Week 0 event this weekend, I noticed a lot of batteries that were not fully restrained. I mentioned it to the teams, and the typical response is: "Oh, we've driven it, and it doesn't move". At which point I show them the R22 that says the battery must be secured in any arbitrary orientation, including turning the robot upside down.

Teams: Fully secure your battery.

BTW: I also saw one team violate the frame perimeter of another team during autonomous. Robots still need to be protected.

[EricH]

I know your are an inspector and not a referee, but are we allowed to, during setup on the field, activate our pneumatics systems via pushing the buttons on the solenoids of our robot? I would like to start a match with our pneumatics systems out of the robot, but during transport, no pressure and with pressure, they would be fully contained within the transport configuration.

As a referee AND an inspector...

I allowed it at the SCRRF Scrimmage. The main concern is safety, so make sure your pathway is clear.

[RyanCahoon]

In R65 (allowed changes to pnumatics), the blue box says: "Do not, for example, paint ... any part of a pneumatic".

I remember a discussion last year about no labels or writing on plastic air tanks. In theory, the ink or adhesive could weaken the tank wall.

However, R65-E allows labeling.

So, can people put stickers, or write, on the air tanks or hoses?

How about getting some shrink tubing, and then writing on that?

[ATannahill]

How about getting some shrink tubing, and then writing on that?
I would be slightly concerned that the heat used to activate the shrink tube might damage the tank or hose. I would raise an eyebrow if I was inspecting your robot.

[Richard Wallace]

... Eagerly awaiting the GDC's word on 2015 Q360. :)

Yup, that was me asking... I saw them answer a question that check valves are illegal (which was expected), but wanted to make sure there was another answer directly applicable to the compressor we're using so an overzealous inspector didn't point to that Q&A and make our whole system worthless. I can't overturn inspectors when dealing with my own team :)For those interested in the Viair 250C-IG, Q360 has been answered:

Q. Are check valves integral to the operation of a compressor legal? Specifically, the VIAIR 250C IG compressor, requires a provided in-line check valve to be attached in order to cooperate correctly. It's 12V, 0.88 CFM, and is rated for 150 PSI working pressure.

A. Per R66-J, any parts or devices that are required by the manufacturer for intended operation are considered in the definition of the whole part. In this case, the check valve is considered part of the compressor and as a pneumatic part may not be modified (that is to say 'removed'). This even holds true, for example, for those legal compressors that require the compressor to be used with the supplied stainless steel hose.

[Al Skierkiewicz]

As to labeling, labels for pneumatic parts are allowed under rule R65. I don't know hwat purpose a label would be on a tank, unless you store both high and low pressure air. Labels on hoses are the same as electrical wiring, I would guess.

As to using manual control of valves during robot setup, I would think the GDC has answered that in the Q&A. Safety is a major concern so it appears that powered movement (electrical or pneumatic) is not allowed. Hand tools may be used, but I believe that is all. I would suggest you ask the Q&A a specific question to be sure.

As to the 148 robot and numbering. I could only suggest to the team that they would want to play on Saturday afternoon and for that reason some numbering scheme that identifies them to other teams in the stands would be appropriate. Since they have always made a great robot, numbering seems to be a common task for them. I would expect a inspector would find them numbering each part of the robot.

[rich2202]

As to labeling, labels for pneumatic parts are allowed under rule R65. I don't know hwat purpose a label would be on a tank, unless you store both high and low pressure air.

One team at Week 0 had 4 white pneumatic tanks. I looked at them, and they did not have "clippard" on them. They did have some part numbers on them. I couldn't tell if they were printed by the manufacturer, or suck on (labeler) by the team.

If I was planning to use white tanks, I would want a label that clearly identified them as non-clippard (or an allowable clippard) because they will be asked over and over again.

[Ginger Power]

I apologize if this is explicitly stated elsewhere on CD or if I'm missing it in the manual but I have a materials test to study for... Is it legal to cover pneumatic air tanks and pneumatic cylinders with anything, like say a carbon fiber covering, for aesthetic purposes? The carbon fiber just slips over the tanks and cylinders and doesn't do anything more than make it look cool. Since it's really not a modification would this be legal? I'm asking for a local team who doesn't generally use CD so I don't have a picture of this specific case.

[Alan Anderson]

As a general rule, don't cover things so much that they can't be seen for inspection.

[Ginger Power]

I'm actually going to be a rookie inspector at the same event they will be attending. In my book their setup doesn't do much to hamper the inspection process. The only issue I could see it bringing up would be preventing the inspector from obviously seeing if there is any damage to the air tanks or cylinders. I don't know if that is enough to say they can't do it.

[Jon Stratis]

I'm actually going to be a rookie inspector at the same event they will be attending. In my book their setup doesn't do much to hamper the inspection process. The only issue I could see it bringing up would be preventing the inspector from obviously seeing if there is any damage to the air tanks or cylinders. I don't know if that is enough to say they can't do it.

Ryan, have them e-mail me a pic of their setup and the sleeve they want to use, and I can give them some more direct feedback. You've already got my e-mail address :)

In general, I don't see a problem with a sleeve over pneumatic components, provided it can be quickly and easily moved/removed for inspection, it doesn't alter the component in any way, and it doesn't compress the component (like a hose clamp would, for example).

[Ginger Power]

I'll have them do that thanks!

[rich2202]

BOM Comment:

KOP items do not have to be listed.

It would be nice if certain KOP items had to be listed, like motors. The reason is: They are limited by part number, and quantity. By explicitly listing them, it is easier to confirm the part number.

[FrankJ]

BOM Comment:

KOP items do not have to be listed.

It would be nice if certain KOP items had to be listed, like motors. The reason is: They are limited by part number, and quantity. By explicitly listing them, it is easier to confirm the part number.

My understanding KOP material has to be on the BOM. The cost is $0.00 so it does not go against the $4000.00

[MrForbes]

This year is different....

[FrankJ]

This year is different....

Teach me to read the rules better. ::rtm::

My BOM just got a lot shorter. :)

[pntbll1313]

My understanding KOP material has to be on the BOM. The cost is $0.00 so it does not go against the $4000.00

That was always my understanding as well but apparently not for 2015 (https://frc-qa.usfirst.org/Question/354/in-the-bill-of-materials-do-we-need-to-include-the-kop-items-in-it).

[Jon Stratis]

That was always my understanding as well but apparently not for 2015 (https://frc-qa.usfirst.org/Question/354/in-the-bill-of-materials-do-we-need-to-include-the-kop-items-in-it).

This is a change for this year, and personally I both like and dislike it. On the one hand, it makes the BOM shorter and easier... But on the other hand, including KOP items makes it more complete and more closely approximates the real world.

[Rosiebotboss]

One more thing on pneumatics I want to put up here, seeing how this is a very popular thread and a LOT of people are reading it, do NOT jump out your Nason Pressure Switch during set up on the field to pre-charge the robot.

Last year, I saw 1 team use a switch that bypassed the Nason Switch to pre charge on the field before a match (and then took the switch out of its socket and the mentor put it in his pocket) and another team use a Leatherman multi tool to jump the 2 wires to pre charge.

This allows teams to over charge (over 120 psi) the system at start up, all the way up to whatever the pressure relief valve was set.

[bachster]

Last year, I saw 1 team use a switch that bypassed the Nason Switch to pre charge on the field before a match (and then took the switch out of its socket and the mentor put it in his pocket) and another team use a Leatherman multi tool to jump the 2 wires to pre charge.

This allows teams to over charge (over 120 psi) the system at start up, all the way up to whatever the pressure relief valve was set.

I've also heard this as advertised as a "trick" to get that extra 5-7 psi between the point the switch cuts off (typically 115 or less) to 120. While lawyering of rules in the past may have allowed teams to convince themselves it was legal, I believe it is specifically not this year, based on a combination of:

R63 To satisfy multiple constraints associated with safety, consistency, Inspection, and constructive innovation, no pneumatic parts
other than those explicitly permitted in Section 4.10: Pneumatic System may be used on the ROBOT

(A jumper is not an explicitly permitted pneumatic part)

R65 All pneumatic COMPONENTS must be used in their original, unaltered condition.

(Jumpering the switch is not using it in its original condition)

R77 The pressure switch requirements are:
...
C. The two wires from the pressure switch must be connected directly the pressure switch input of the PCM controlling the compressor or, if controlled using the roboRIO and a Spike relay, to the roboRIO.
D. If connected to the roboRIO, the roboRIO must be programmed to sense the state of the switch and operate the relay module that powers the compressor to prevent over-pressuring the system.

(Jumpering across the switch is not directly connecting it to the PCM or roboRIO)

[bachster]

BOM Comment:

KOP items do not have to be listed.

It would be nice if certain KOP items had to be listed, like motors. The reason is: They are limited by part number, and quantity. By explicitly listing them, it is easier to confirm the part number.

Agreed. I wish FIRST put a little more emphasis on the BOM, not even from a cost perspective but just from a real world perspective and emphasizing the importance of being accurate and specific. I've started using the BOM as a build-season-long job for rookies on the build team, to get them to learn what all the components are and where they come from, ideally real-time as they are added to the robot. I conveniently didn't tell them about this, and I'm not sure they've read the BOM rules closely enough to realize it themselves. ;) I'd like our BOM to reflect our whole robot.

It would also be nice from an inspection perspective to have all the KOP items listed, especially since the definition of KOP includes any year's checklist, FIRSTChoice, and PDV items. A team could claim pretty much anything falls under one of those categories and I'd be hard pressed to disprove it. I'd like to see teams have to call out what it is and where it's from, even if that is "2002 KOP" or "2013 FIRSTChoice" and the cost is $0.

[Jon Stratis]

It would also be nice from an inspection perspective to have all the KOP items listed, especially since the definition of KOP includes any year's checklist, FIRSTChoice, and PDV items. A team could claim pretty much anything falls under one of those categories and I'd be hard pressed to disprove it. I'd like to see teams have to call out what it is and where it's from, even if that is "2002 KOP" or "2013 FIRSTChoice" and the cost is $0.

Remember that it's not your job to disprove it... It's the team's job to prove that their robot is legal. If you're inspecting Wildstang (sorry Al!) And they point to a gizmo and say " We didn't have to list that because it came in the 1995 Kit of Parts", my first question would be " and it still works?" Followed closely by " you mean in the past 20 years you guys have never cleaned house and chucked old stuff? How much storage do you have at your build space?", And finally ending with "could you pull out the KoP checklist from 1995 and show me the part listed there? Like all you kids, I wasn't exactly around FIRST back then..."

[rich2202]

Last year, I saw 1 team use a switch that bypassed the Nason Switch to pre charge on the field before a match

If it happened this year, I would cite Rule R69" ... the compressor must still be controlled and powered by the ROBOT". Shorting the switch is no longer "controlled" by the ROBOT. I know that R69 talks about off-board compressor. However, the wording includes "still", which implies a condition that exists prior to removing the compressor from the robot.

[rich2202]

The Inspection Checklist includes Software Version numbers for not only the DS and roboRIO, but also for the Talons, Jaguars, PCM, and PDP.

I remember last year finding the DS and cRIO on the dashboard. Do you have instructions for checking the Talons, Jaguars, PCM, and PDP?

[ATannahill]

The Inspection Checklist includes Software Version numbers for not only the DS and roboRIO, but also for the Talons, Jaguars, PCM, and PDP.

I remember last year finding the DS and cRIO on the dashboard. Do you have instructions for checking the Talons, Jaguars, PCM, and PDP?
These can be found on the diagnostic tab of the driver station. http://wpilib.screenstepslive.com/s/4485/m/24192/l/144976-frc-driver-station-software

[rich2202]

These can be found on the diagnostic tab of the driver station. http://wpilib.screenstepslive.com/s/4485/m/24192/l/144976-frc-driver-station-software

Thanks.

If a team is using a Talon or Jag in PWM mode, do we still need to check the firmware version?

[MrBasse]

One more thing on pneumatics I want to put up here, seeing how this is a very popular thread and a LOT of people are reading it, do NOT jump out your Nason Pressure Switch during set up on the field to pre-charge the robot.

Last year, I saw 1 team use a switch that bypassed the Nason Switch to pre charge on the field before a match (and then took the switch out of its socket and the mentor put it in his pocket) and another team use a Leatherman multi tool to jump the 2 wires to pre charge.

This allows teams to over charge (over 120 psi) the system at start up, all the way up to whatever the pressure relief valve was set.

If you are going to argue this then I would say that the inspectors better stop doing it on our robot for inspection while our students are watching. It sets a bad example and gives kids the idea it is an okay method to reach that ever elusive 120 PSI we are allowed.

It wouldn't be too hard to rig a switch that looked official for an inspector to use that gives better control and a more professional appearance over stabbing a screwdriver in there to short the leads.

[protoserge]

If you are going to argue this then I would say that the inspectors better stop doing it on our robot for inspection while our students are watching. It sets a bad example and gives kids the idea it is an okay method to reach that ever elusive 120 PSI we are allowed.

It wouldn't be too hard to rig a switch that looked official for an inspector to use that gives better control and a more professional appearance over stabbing a screwdriver in there to short the leads.

The intent of the shorting of the pressure switch by inspectors is to verify the pressure relief valve is set at 120 psi at the event. While I don't endorse teams using a screwdriver to jump the pressure switch, the inspectors are watching the pressure to confirm the relief valve opens at 120 PSI. If the team fails this test, the inspector instructs the team to properly calibrate their relief valve.

I find it important for students and teams to understand that a failed or shorted pressure switch can happen. The inspector testing the circuit by shorting the switch is a valid and important part of the inspection. It is important for teams to understand the failsafes in place in a pneumatic system to reduce the risk of a catastrophic failure.

If it means anything, I never used a screwdriver to short the switch. I always carried a set of alligator clip jumper wires for this since I felt it looked more professional. I also explained to the team why I was testing their pneumatic system and what the ramifications of a failed switch and improperly set pressure relief valve were. The inspector isn't someone charged with failing a team due to mysterious reasoning outside of the watchful eye of the team. The inspector is also responsible for helping teams learn and understand to keep everyone safe.

[Rosiebotboss]

If you are going to argue this then I would say that the inspectors better stop doing it on our robot for inspection while our students are watching. It sets a bad example and gives kids the idea it is an okay method to reach that ever elusive 120 PSI we are allowed.

It wouldn't be too hard to rig a switch that looked official for an inspector to use that gives better control and a more professional appearance over stabbing a screwdriver in there to short the leads.

EVERY time I do this while inspecting a team, I tell the kids why I am doing it. I am doing it to check the relief valve is relieving when it is supposed to, at about 125psi. That is the ONLY time I want to see a team jump that switch. And I add that if I see them doing it on the field, I will dump their air prior to match startup, after consulting with the Head Ref.

[Thad House]

Something Ive always wondered, and I've always gotten different answers to. Is the 125 for the pressure relief valve the pressure it releases to, or the pressure it starts releasing. I've always seen that if its set to never let the pressure go above 125, it usually reliefs down to about 110 psi. If we set it so it wont let the pressure go above 135, if reliefs down to 125. Which method is correct? Some inspectors ive seen want it one way, and some want it another.

[ATannahill]

Something Ive always wondered, and I've always gotten different answers to. Is the 125 for the pressure relief valve the pressure it releases to, or the pressure it starts releasing. I've always seen that if its set to never let the pressure go above 125, it usually reliefs down to about 110 psi. If we set it so it wont let the pressure go above 135, if reliefs down to 125. Which method is correct? Some inspectors ive seen want it one way, and some want it another.
The relief valve must be attached directly to the compressor or attached by legal hard fittings (e.g. brass, nylon, etc.) connected to the compressor output port. If using an off-board compressor, an additional relief valve must be included on the ROBOT.

If necessary, Teams are required to adjust the relief valve to release air at 125 psi. The valve may or may not have been calibrated prior to being supplied to Teams.

You should not have to worry because it will only reach 125 when being tested.

[Joe Ross]

Thanks.

If a team is using a Talon or Jag in PWM mode, do we still need to check the firmware version?

There are no firmware requirements for Jaguars used in PWM mode. There are firmware requirements for Talon SRXs in PWM mode (But not Talons or Talon SRs). The Talon SRX user manual (http://www.crosstheroadelectronics.com/Talon%20SRX%20User%27s%20Guide.pdf) gives several methods to determine if the firmware version is less then 0.28.

[FrankJ]

The load on the pressure switch is in the milliamps. The electrical danger of shorting the switch is miniscule. It is also clearly against the rules for using this method for charging the air system. To say the observing youth cannot understand the difference is almost silly. :]

Now if you are using a screwdriver to bypass the worn out solenoid on your VW Beetle's starter motor....

[Thad House]

You should not have to worry because it will only reach 125 when being tested.

Yeah, but if you have it set to never let the pressure go above 125, depending on the pressure switch, the relief will start letting out pressure before the switch detects its at full pressure. We've had to go find different pressure switches before, because the switch would trigger at 115, but the relief valve started releasing air at 110, in order to make it so pressure never got above 125.

[AdamHeard]

Yeah, but if you have it set to never let the pressure go above 125, depending on the pressure switch, the relief will start letting out pressure before the switch detects its at full pressure. We've had to go find different pressure switches before, because the switch would trigger at 115, but the relief valve started releasing air at 110, in order to make it so pressure never got above 125.

I've seen several inspectors flip out over this one.

The KOP release valve also doesn't always trigger at exactly the same psi, which has caused some inspectors to ask us to keep adjusting it.

[FrankJ]

I always set the cracking pressure, the pressure that the relief first opens to 125 PSI. The full flow pressure is somewhat higher. The re-seat pressure is usually somewhat lower. If the pressure is different at inspection, we adjust to accommodate the inspector. It is not a precision device. You do not want the cracking pressure anywhere near the working pressure.

[JamesCH95]

Something Ive always wondered, and I've always gotten different answers to. Is the 125 for the pressure relief valve the pressure it releases to, or the pressure it starts releasing. I've always seen that if its set to never let the pressure go above 125, it usually reliefs down to about 110 psi. If we set it so it wont let the pressure go above 135, if reliefs down to 125. Which method is correct? Some inspectors ive seen want it one way, and some want it another.

I always set the cracking pressure, the pressure that the relief first opens to 125 PSI. The full flow pressure is somewhat higher. The re-seat pressure is usually somewhat lower. If the pressure is different at inspection, we adjust to accommodate the inspector. It is not a precision device. You do not want the cracking pressure anywhere near the working pressure.

^What this guy said.

The specific wording "... to release air at 125psi..." is the key phrase. Does the valve release air at 125psi (or lower)? If yes, you're good to go. If no, then you're illegal. Thus I would wager your first setup to be correct, where it opens at 125psi and closes at 110psi. Allowing the pressure to reach 135 psi is CLEARLY a violation of the rules [R76] blue box.

[Gary Dillard]

I'm hearing reports of robots using > 7 MB/S (Rule R49) which seem to be causing other robots to lose comms and reset. There's no penalty listed for the rule, if it's identified by FMS during a match it seems like they shouldn't be allowed to compete until they correct it, but how do you test it?

[AllenGregoryIV]

I always set the cracking pressure, the pressure that the relief first opens to 125 PSI. The full flow pressure is somewhat higher. The re-seat pressure is usually somewhat lower. If the pressure is different at inspection, we adjust to accommodate the inspector. It is not a precision device. You do not want the cracking pressure anywhere near the working pressure.

That's the way I've always done it. The goal is to keep pressures safe and for the relief valve never to release air unless there is a problem with system, i.e. the stored air reaches above 125psi.

[Al Skierkiewicz]

WoW! I go on vacation for a few days to Duluth and the thread goes wild. So first to a few answers,
Jon, We don't have as much storage as we used to and do have stuff that goes most of the way back. We're resourceful and nostalgic. (OK so I am)
Shorting out the pressure switch is the prescribed method for checking the over pressure valve as described by FIRST staff and that method has been used since the manufacturer stopped supplying the valve pre-calibrated. A good team member or inspector will check that the valve vents above 125 psi after calibration and tightening of the lock ring. It is not calibrated if it vents below 125 psi.
Shorting out the pressure switch, attaching another compressor or bypassing the robot control system to charge the pneumatic system in queue or on the field has never been legal. Do not listen to the team that tells you it is. There are considerable penalties in the rules (game, robot and tournament).

Now on to a few items that were issues during week one.
Latest, greatest firmware.
The most recent version of the Inspection Checklist has a great list of the all the firmware required for this week of competition. If and when that changes, the Checklist will be updated. Go to the appropriate website now and download the firmware versions for the PDP, PCM, RoboRio, Jag and Talon, and driver station. Bring those with you so you can load them prior to inspection. The version numbers are displayed on the Dashboard diagnostic tab.

Software Versions – Software/firmware for devices is at or above listed versions (As of March 2, 2015)
Driver Station – 08021500 or newer <R80> (Note the version number is a date in the format of, DD/MM/YY00)
roboRIO – v23 and 2.1.0f3 <R45>
Talon SRX – v.28 for PWM, v1.01 for CAN <R41, R59>
Jaguars – v109 <R59>
PCM – v1.62 <R60>
PDP – v1.37 <R61>

Team Numbers,
Must be 3.5 inches high or greater, 1/2" stroke or greater and must be black on white background with 1" (white) border all the way around. Nearly half of all robots at Duluth needed number adjustments.

We saw some teams show up with old, white pneumatic storage tanks. While the manufacturer was giving free exchange for tanks last year, that is no longer taking place. You will be required to replace any old tanks prior to competing.

[Batterink]

We saw some teams show up with old, white pneumatic storage tanks. While the manufacturer was giving free exchange for tanks last year, that is no longer taking place. You will be required to replace any old tanks prior to competing.

We have none clippard white tanks. They were legal last year. Are all white tanks now disallowed?, or still just the clippard white tanks?

Also. When we went to do our checklist and update our firmware on bag and tag day, we noticed that the pdp doesn't who up anywhere (DS, or on the web interface thingy). Does anyone know of a solution to this? or should we be ordering a new pdp for comp?

Thanks in advance.

[Al Skierkiewicz]

Also. When we went to do our checklist and update our firmware on bag and tag day, we noticed that the pdp doesn't who up anywhere (DS, or on the web interface thingy). Does anyone know of a solution to this? or should we be ordering a new pdp for comp?

Thanks in advance.
You must connect the PDP to the RoboRio via CAN even if you do not use the CAN buss for anything else. The PDP data collection function will be used in logs for other purposes and needs to be connected and the firmware up to date.

[Bryan Herbst]

I'm hearing reports of robots using > 7 MB/S (Rule R49) which seem to be causing other robots to lose comms and reset. There's no penalty listed for the rule, if it's identified by FMS during a match it seems like they shouldn't be allowed to compete until they correct it, but how do you test it?

You are correct that R49 has no penalty associated with it. That might be a good QA question- I would assume that the answer is that they will not be allowed to play if it is repeated or causing problems for other teams.

Generally if I see a team using > 7 Mb/s, I let them know they need to fix it, and it stops being a problem. If it happens a second time, I'll send a CSA after them, and that is the end of it.

WPI has a page on how to measure bandwidth usage. (http://wpilib.screenstepslive.com/s/3120/m/8559/l/95886-measuring-bandwidth-usage)

[Batterink]

You must connect the PDP to the RoboRio via CAN even if you do not use the CAN buss for anything else. The PDP data collection function will be used in logs for other purposes and needs to be connected and the firmware up to date.

We had it connected via can. (I was told by the electrical person that it was correctly and securely connected) Hopefully it was just a bad connections or wire. However, is it possible that the pdp can is broken, but the pdp is still functional?

[Caleb Sykes]

Something Ive always wondered, and I've always gotten different answers to. Is the 125 for the pressure relief valve the pressure it releases to, or the pressure it starts releasing. I've always seen that if its set to never let the pressure go above 125, it usually reliefs down to about 110 psi. If we set it so it wont let the pressure go above 135, if reliefs down to 125. Which method is correct? Some inspectors ive seen want it one way, and some want it another.

A good team member or inspector will check that the valve vents above 125 psi after calibration and tightening of the lock ring. It is not calibrated if it vents below 125 psi.

Just to be clear, which of the 2 methods described by Thad House is correct? Should it begin venting at ~115psi, or at 125psi?

[Al Skierkiewicz]

Batt,
It is possible to have a problem in wiring or to have an issue with the CAN bus interfaces. I suggest checking the user's manual for the PDP first and then try checking with CTRE to see if there is something else that you can check.

The correct operation is to vent at 125 psi or above. This part has a repeatability of +/- at least 2 psi. A good indication is a wet finger on top of the valve. Venting will cause some bubbles.

[rich2202]

We have none clippard white tanks. They were legal last year. Are all white tanks now disallowed?, or still just the clippard white tanks?


Just the Clippard White Tanks. However, if you have white tanks, it should be easily evident that they are not the Clippard ones.

[Caleb Sykes]

The correct operation is to vent at 125 psi or above. This part has a repeatability of +/- at least 2 psi. A good indication is a wet finger on top of the valve. Venting will cause some bubbles.

Calibrating the relief valve in this way means that the pressure on the stored side could exceed 125psi if the pressure switch were to fail. Should it concern us that many pneumatic components like the kit tubing are only rated for 125psi?

My understanding of the relief valve was that it would provide a safeguard if the pressure switch were to fail. Calibrating it as you described means that it is not protecting the components rated for 125psi.

[FrankJ]

We had it connected via can. (I was told by the electrical person that it was correctly and securely connected) Hopefully it was just a bad connections or wire. However, is it possible that the pdp can is broken, but the pdp is still functional?

The Georgia Southern Classic last weekend, we had several PDPs that would not talk over CAN. Confirmed correct connections/wiring by several CSAs (orange hats). The FTA eventually said to pass them without coms to the PDP.

[FrankJ]

Calibrating the relief valve in this way means that the pressure on the stored side could exceed 125psi if the pressure switch were to fail. Should it concern us that many pneumatic components like the kit tubing are only rated for 125psi?

My understanding of the relief valve was that it would provide a safeguard if the pressure switch were to fail. Calibrating it as you described means that it is not protecting the components rated for 125psi.

The working pressure of the components is 125 PSI. Slightly exceeding this is not an issue. From a practical point of view anything less than 140 is slightly. (Not to say your system should ever reach 140.) If one is really concerned about this, they should not be using small, cheap, uncalibrated pressure gauges to set these things.

[Bryce Paputa]

I know that we need to ask q&a, but do all parts of our robot have be connected to each other after we place it on the field and at the start of the match?

[notmattlythgoe]

I know that we need to ask q&a, but do all parts of our robot have be connected to each other after we place it on the field and at the start of the match?

When the match starts and after that, yes. You can have separate parts while setting up though.

[rich2202]

I know that we need to ask q&a, but do all parts of our robot have be connected to each other after we place it on the field and at the start of the match?

Not only that, but they have to stay connected. Otherwise, it would be a violation of G25.

[Alan Anderson]

...is it possible that the pdp can is broken, but the pdp is still functional?

Yes, if you define "functional" to mean that it distributes power to the branch circuits. The color of the two LEDs on the PDP will help tell you if it is functioning the rest of the way. Blinking red means no CAN communication. Blinking yellow means disabled. Off means it's probably broken.

[scca229]

Yes, if you define "functional" to mean that it distributes power to the branch circuits. The color of the two LEDs on the PDP will help tell you if it is functioning the rest of the way. Blinking red means no CAN communication. Blinking yellow means disabled. Off means it's probably broken.

Off-Topic but leads into the above:

What I want to know is how in the heck do I clear a blinking orange from a previous brown-out? I can find that it is a "sticky" condition but no clear instructions/how-to on how to clear it. I've seen something that says go into the CAN page for the PDP can continuously refresh it and it magically clears...no dice when I tried it.

[RufflesRidge]

Off-Topic but leads into the above:

What I want to know is how in the heck do I clear a blinking orange from a previous brown-out? I can find that it is a "sticky" condition but no clear instructions/how-to on how to clear it. I've seen something that says go into the CAN page for the PDP can continuously refresh it and it magically clears...no dice when I tried it.

Close. "Double clicking" Self-Test (which may actually take repeated clicking to register properly) will clear sticky faults.

You should also be able to clear them from code, obviously doing so each time the code starts would eliminate the point, but linking a dashboard control or button to clearing may be useful if you don't want to fiddle with the button on the webdashboard.

[BJT]

I checked on this when that compressor became an option a few years ago. The manufacturer requires it as it supplies a cooling path for the hot air. On that compressor only, as it is required by the manufacturer, the hose is considered part of the compressor and must be attached. As a note, I have only seen one in inspection.

Al, in our pit at northern lights last weekend you asked about how warm the 250c and its hose got during use. When the kids got back to the pits after a match, I checked the head and it was just a little warm. the hose was cool. I then had them tether it and ran it at about 100psi for 2:30 by venting a bit of air out the dump valve. The head was warm but still very comfortable to touch. the connection to the braided hose was warm and the braided hose was still cool to the touch.

[Sperkowsky]

WoW! I go on vacation for a few days to Duluth and the thread goes wild. So first to a few answers,
Jon, We don't have as much storage as we used to and do have stuff that goes most of the way back. We're resourceful and nostalgic. (OK so I am)
Shorting out the pressure switch is the prescribed method for checking the over pressure valve as described by FIRST staff and that method has been used since the manufacturer stopped supplying the valve pre-calibrated. A good team member or inspector will check that the valve vents above 125 psi after calibration and tightening of the lock ring. It is not calibrated if it vents below 125 psi.
Shorting out the pressure switch, attaching another compressor or bypassing the robot control system to charge the pneumatic system in queue or on the field has never been legal. Do not listen to the team that tells you it is. There are considerable penalties in the rules (game, robot and tournament).

Now on to a few items that were issues during week one.
Latest, greatest firmware.
The most recent version of the Inspection Checklist has a great list of the all the firmware required for this week of competition. If and when that changes, the Checklist will be updated. Go to the appropriate website now and download the firmware versions for the PDP, PCM, RoboRio, Jag and Talon, and driver station. Bring those with you so you can load them prior to inspection. The version numbers are displayed on the Dashboard diagnostic tab.

Software Versions &ndash; Software/firmware for devices is at or above listed versions (As of March 2, 2015)
Driver Station &ndash; 08021500 or newer <R80> (Note the version number is a date in the format of, DD/MM/YY00)
roboRIO &ndash; v23 and 2.1.0f3 <R45>
Talon SRX &ndash; v.28 for PWM, v1.01 for CAN <R41, R59>
Jaguars &ndash; v109 <R59>
PCM &ndash; v1.62 <R60>
PDP &ndash; v1.37 <R61>

Team Numbers,
Must be 3.5 inches high or greater, 1/2" stroke or greater and must be black on white background with 1" (white) border all the way around. Nearly half of all robots at Duluth needed number adjustments.

We saw some teams show up with old, white pneumatic storage tanks. While the manufacturer was giving free exchange for tanks last year, that is no longer taking place. You will be required to replace any old tanks prior to competing.
I was checking our robot for final problems and noticed the white background extends only 3/4 of an inch at some points. If I velcro a peice of a larger foam sheet behind it will it count as part of the 1 inch.

[EricH]

I was checking our robot for final problems and noticed the white background extends only 3/4 of an inch at some points. If I velcro a peice of a larger foam sheet behind it will it count as part of the 1 inch.

Most likely, I would say so. The key is that the numbers need 1" of white space around them, and there are no specific requirements that the 1" all be on the same plane as the numbers.


Not related to above:
Just so Al doesn't have to:

If you are making modifications, make SURE to get reinspected! (Except as allowed by T10 A-F). No matter how minor the modification, if it isn't an allowed exception, re-inspect. And if a ref asks you if you got reinspected after a modification--be honest, it makes life easier on everybody.

[Sperkowsky]

Most likely, I would say so. The key is that the numbers need 1" of white space around them, and there are no specific requirements that the 1" all be on the same plane as the numbers.



Just so Al doesn't have to:

If you are making modifications, make SURE to get reinspected! (Except as allowed by T10 A-F). No matter how minor the modification, if it isn't an allowed exception, re-inspect. And if a ref asks you if you got reinspected after a modification--be honest, it makes life easier on everybody.
I plan on bringing the foam precut with the rest of the modification stuff. It would be a matter of about 2 minutes to put on so I'd do it before we got inspected.

[EricH]

I plan on bringing the foam precut with the rest of the modification stuff. It would be a matter of about 2 minutes to put on so I'd do it before we got inspected.

Wasn't referencing you--sorry, should have made that clear.


Let's just say that there was one team that gave us a little trouble along those lines at a couple of points--the second time, they HAD been reinspected but we had a hard time finding the paperwork.

[rich2202]

I was checking our robot for final problems and noticed the white background extends only 3/4 of an inch at some points. If I velcro a peice of a larger foam sheet behind it will it count as part of the 1 inch.

Taping a white piece of paper onto it would work for me.

[Sperkowsky]

Taping a white piece of paper onto it would work for me.
Haha well that would kinda take away from the work I did to make the number plates to begin with.

[Al Skierkiewicz]

Ben,
Thanks for the report, it would seem that the hose is doing it's job.

Even white gaffer's tape works for extending the border. It is ugly but it satisfies the rule.

Any changes that you think are minor may be a major change in the eyes of other competitors. Please check with the RI's before you make the change. We had some great teams who constantly worked on their robots in Duluth this weekend. They were coming and weighing parts that they were planning for modification. If we see it first, we can tell you if it is legal and a good way to attach it to your robot so that re-inspection will be painless. Thank you to all the Duluth teams who were re-inspected prior to the end of qualifying.

The procedure for calibrating the pressure relief valve will not overly stress your pneumatic system. Many parts, tubing included, list the 'working' pressure. "Burst' pressure is far above that. The tubing at room temperature is generally rated for 150-165 psi as I remember. The relief valve is in circuit as you would expect. It the software, pressure switch or compressor controller were to fail and the compressor was running constantly, the pressure would never exceed burst pressure for any components. Under certain conditions, a second pressure relief valve is required for components that have a reduced burst pressure. See R66.

[Jon Stratis]

The procedure for calibrating the pressure relief valve will not overly stress your pneumatic system. Many parts, tubing included, list the 'working' pressure. "Burst' pressure is far above that. The tubing at room temperature is generally rated for 150-165 psi as I remember. The relief valve is in circuit as you would expect. It the software, pressure switch or compressor controller were to fail and the compressor was running constantly, the pressure would never exceed burst pressure for any components. Under certain conditions, a second pressure relief valve is required for components that have a reduced burst pressure. See R66.

Al - I meant to ask up in Duluth, but forgot while we were up there... could you explain the reasoning behind R66D?
Solenoid valves that are rated for a maximum working pressure that is less than 125 psi rating mandated above are permitted, however if employed, an additional pressure relief valve must be added to the low pressure side of the main regulator. The additional relief valve must be set to a lower pressure than the maximum pressure rating for the solenoid valve,

I'm just wondering what the second pressure relief valve does that our relieving regulator doesn't already do. Is it required incase the relieving regulator fails to relieve? The first pressure relief valve is required to be attached to the compressor through hard fittings, but the second one can be anywhere on the low pressure side, connected through tubing.

[Al Skierkiewicz]

Jon,
There is some solenoid valves that are designed to be run at 25-45 psi. The rules allow a team to use a second regulator that is down stream from the main regulator to supply this much lower pressure. The rules do not require that secondary regulators be relieving. So to protect a failure in these low pressure components, FIRST Engineering decided to add the secondary relief valve should a failure occur. Such a failure could cause pressure in excess of the burst pressure of these other solenoid valves. I think in the past few years I have only seen one or two robots with these valves. They may be more common in other countries than here in the US.

[Jon Stratis]

It definitely makes sense if it's downstream of a non-relieving regulator when the pressure rating is that low. I had been thinking more along the lines of solenoids like these (https://www.mettleair.com/store/valves/sv.html?cat=38&dir=desc&limit=15&order=price&price=20-30) that are rated "0.15-0.8 MPa / 22-116 PSI" - per the letter of the rules, they need a secondary pressure relief valve even though we're talking about just a couple of PSI away from 125 PSI.

[Al Skierkiewicz]

Jon,
We have used these valves in the past and some robots this weekend had them installed. The 'recommended' working pressure range is published but when asked the manufacturer has said the working pressure is greater than that. The recommended pressure is that range in which valve life is optimum. Above that range, internal items wear a little faster and below the range, the valve cannot be guaranteed to operate. Burst pressure, (which is rarely published anymore) is greater than 150 psi.

[FrankJ]

I'm just wondering what the second pressure relief valve does that our relieving regulator doesn't already do. Is it required incase the relieving regulator fails to relieve? The first pressure relief valve is required to be attached to the compressor through hard fittings, but the second one can be anywhere on the low pressure side, connected through tubing.

I am not Al, but. A large number of industrial solenoid valves have a working pressure of 110-120 PSI. They would not be legal prior to 2011 when the provision of the 2nd relief valve was added. The second relief valve with lower set pressure than the valve rating protects the valve if the primary regulator breaks or is turned to higher than the working pressure of the valve. Since the set pressure of the relief valve is lower than the allowed stored pressure it has to be on the working pressure side. It is a back up to a back up.

[Retired Starman]

Wasn't referencing you--sorry, should have made that clear.


Let's just say that there was one team that gave us a little trouble along those lines at a couple of points--the second time, they HAD been reinspected but we had a hard time finding the paperwork.

At Georgia Southern Classic this past weekend, we formalized the re-inspection process. When a team came up for re-inspection, we recorded this on a separate form attached to their original inspection form. We noted what was changed, got a new weight if necessary, signed the form, time stamped it, got the team to sign it, then put a dot sticker with the re-inspection number on it by their original sticker. Took only a minute to do and EVERYONE could verify that the r-eispection had been done. This keeps everyone out of trouble later.

Don't know why FIRST doesn't institutionalize a similar process, especially after the incidences last season.

[Gary Dillard]

There's an old thread around somewhere - I have an email from SMC Tech Support in 2010 stating that their SY3000 series valves (rated operating pressure of 100 psi) "will not catastrophically fail at or below 125 PSI due to air pressure alone". They use the JIS standard proof pressure definition of 1.5 times maximum operating pressure. I researched it back then to show that we were in compliance with the rules and didn't required an additional relief valve.

[FrankJ]

There's an old thread around somewhere - I have an email from SMC Tech Support in 2010 stating that their SY3000 series valves (rated operating pressure of 100 psi) "will not catastrophically fail at or below 125 PSI due to air pressure alone". They use the JIS standard proof pressure definition of 1.5 times maximum operating pressure. I researched it back then to show that we were in compliance with the rules and didn't required an additional relief valve.
Rule 66D: D. Solenoid valves that are rated for a maximum working pressure that is less than 125 psi rating mandated above are
permitted, however if employed, an additional pressure relief valve must be added to the low pressure side of the main
regulator. The additional relief valve must be set to a lower pressure than the maximum pressure rating for the solenoid
valve,
The rule says for valves with working pressures below 125 a secondary relief valve is required. While I agree the SMC would be safe without the extra relief valve, unless the email said to effect that working pressure or operating pressure is greater than 125 psi, by rule you need the extra relief valve.

[Richard Wallace]

There's an old thread around somewhere.This one (http://www.chiefdelphi.com/forums/showthread.php?t=124558)?

[FrankJ]

I am a little surprised & pleased by this Q&A. If this is in your plans, I would have the drivers keep a print out of this with them.
Q. During match setup, are teams allowed to actuate pneumatics by pushing the control switch/button on the solenoid?
2015-02-27 by FRC0888
A. There are no rules that would prohibit this, however please ensure you are doing so safely.
2015-03-02

[Gary Dillard]

This one (http://www.chiefdelphi.com/forums/showthread.php?t=124558)?

No, this one (http://www.chiefdelphi.com/forums/showthread.php?t=81946)

It also includes a link to the GDC answer to Q&A that year that said it was sufficient, I don't think any circumstances have changed since then even though that ruling is obviously not binding this year.

[FrankJ]

No, this one (http://www.chiefdelphi.com/forums/showthread.php?t=81946)

It also includes a link to the GDC answer to Q&A that year that said it was sufficient, I don't think any circumstances have changed since then even though that ruling is obviously not binding this year.

It would be nice if the GDC would reword the rule to what they actually accept. The SMC response clearly says the valve can malfunction at 125 psi. It just will not blow up at that pressure. :]
(emphasis mine)
Gary,
We rate that at a maximum pressure of 100 psi due to the fact that the SY valve will shift automatically (no voltage necessary) at about 125 psi. At this pressure, the pilot section can generate enough force to shift without the assistance of a coil.
Regards,
Bryon Hartzog
Technical Support
SMC Corporation of America

[IKE]

Both weekends, I have noticed a lot of teams with fuses not properly seated into the Power Distribution Boards. It is really easy to think you have them installed, when in reality they need to be pushed in another 1/8 inch.
See page 13 of the PDP guide.
http://crosstheroadelectronics.com/PDP%20User's%20Guide.pdf

One of the Waterford event Championships had some intermittent radio in their final match. Upon further inspection, their fuse had started to wiggle loose as they were not properly seated. As this was their final match, I do not know for certain that this was related to the radio issue, but it very wll may have been.

I had a CTRE rep at my first district event that checked these on all the robots, but I missed checking these myself until Saturday at my second event. When they are partially inserted, the robot works just fine and may never exhibt a problem. But an impact like hitting some totes, a wall, or the general vibration of driving around on Omni wheels can cause them to wiggle loose if they are not properly installed in the first place.

[Al Skierkiewicz]

Ike,
Thanks for the reminder. Everyone, the fuses are properly inserted when they are nearly flush with the surrounding plastic of the PDP. Please push in on all fuses and breakers on the PDP before you compete.

[ozrien]

Both weekends, I have noticed a lot of teams with fuses not properly seated into the Power Distribution Boards. It is really easy to think you have them installed, when in reality they need to be pushed in another 1/8 inch.
See page 13 of the PDP guide.
http://crosstheroadelectronics.com/PDP%20User's%20Guide.pdf

Additionally check out page 7. I've seen a few teams forget to place the lock-washers in PDP (battery harness). Without them the screws will loosen over time.

[Mr V]

Both weekends, I have noticed a lot of teams with fuses not properly seated into the Power Distribution Boards. It is really easy to think you have them installed, when in reality they need to be pushed in another 1/8 inch.
See page 13 of the PDP guide.
http://crosstheroadelectronics.com/PDP%20User's%20Guide.pdf

One of the Waterford event Championships had some intermittent radio in their final match. Upon further inspection, their fuse had started to wiggle loose as they were not properly seated. As this was their final match, I do not know for certain that this was related to the radio issue, but it very wll may have been.

I had a CTRE rep at my first district event that checked these on all the robots, but I missed checking these myself until Saturday at my second event. When they are partially inserted, the robot works just fine and may never exhibt a problem. But an impact like hitting some totes, a wall, or the general vibration of driving around on Omni wheels can cause them to wiggle loose if they are not properly installed in the first place.

There was a robot at the event that I was at this weekend that did not have their fuses installed properly who was having a loss of connection when they had an impact or went over the scoring platform at speed. Installing the fuses properly seemed to fix the issue.

I've noticed that it seems like the terminals for the fuse are not centered perfectly in all of the PDPs. This leads to the fuse body bottoming out on the case so it seems that it is fully inserted. Applying a little sideways force while pressing down allows the fuse to get past the case and be fully inserted.

[FrankJ]

Slightly different subject of unexpected Q&As
Q429 Q. We are seeking clarification for R4. If a robot has two interchangeable mechanisms such that only one of them can be on the robot at a time. Would that robot be able to be counted under two weights for two different configurations, One weight for mechanism A and one weight for mechanism B? Or would both mechanisms need to be included together in the final robot weight?
FRC4476 on 2015-02-27
A. If you're intent is to go through Inspection once, everything must be included, and thus under the weight limit (per R4). Alternatively, you can pass Inspection with the first element, but if you want to switch it out for the second element, you must be reinspected with only that second element and compete with that element (per T10). If you want to go back to the first element, you must be reinspected with the first element again.

This says you can reuse mechanisms pulled off the robot, that would exceed the weight limit if you have the robot reinspected. Different than what I think this was generally interpreted in years past. Another Q&A I would have printed if you plans include this.

[AllenGregoryIV]

Slightly different subject of unexpected Q&As


This says you can reuse mechanisms pulled off the robot, that would exceed the weight limit if you have the robot reinspected. Different than what I think this was generally interpreted in years past. Another Q&A I would have printed if you plans include this.

That is a very dramatic departure from the precedent set in 2013 with the full court blockers. I'm wondering if this is just a mistake on the GDCs part.

Edit: doesn't seem like it was a mistake as it's confirmed in Q440 (https://frc-qa.usfirst.org/Question/440/is-there-a-limit-to-the-number-of-t10-reinspections-for-example-robot-exceeds-120-with-part-a-and-part-b-but-only-a-or-b-is-used-but-not-both-at-the-same-time-robot-passes-inspection-with-part-a)

We are already reinspected before every match any way since, we almost always drill at least one hole or add one zip tie. So it just looks inspectors are going to be very busy at events from now on.

[Ed Sparks]

That is a very dramatic departure from the precedent set in 2013 with the full court blockers. I'm wondering if this is just a mistake on the GDCs part.

Edit: doesn't seem like it was a mistake as it's confirmed in Q440 (https://frc-qa.usfirst.org/Question/440/is-there-a-limit-to-the-number-of-t10-reinspections-for-example-robot-exceeds-120-with-part-a-and-part-b-but-only-a-or-b-is-used-but-not-both-at-the-same-time-robot-passes-inspection-with-part-a)...

Looks like I'll be retiring as an inspector real soon ........ The pay isn't that good anyway.

[Richard Wallace]

Looks like I'll be retiring as an inspector real soon ........ The pay isn't that good anyway.Say it ain't so, Ed.

I agree this "change" is going to make a lot of work that (IMO) should not be necessary, both for volunteers and competitors. The veneer is wearing thinner every year on the myth of six week build.

[GaryVoshol]

I agree this "change" is going to make a lot of work that (IMO) should not be necessary, both for volunteers and competitors. The veneer is wearing thinner every year on the myth of six week build.

So a team has a 4-match turn-back and decides to make a change. 2.5 matches in, they get it done and now expect the inspectors to do the re-inspection. In time for their match. Right.

And, as soon as a team starts making modifications, an inspector should tell the head ref that their sticker is null and void. If they come out without the LRI confirming re-inspection, the whole alliance gets a Red Card. Ouch.

[AdamHeard]

So a team has a 4-match turn-back and decides to make a change. 2.5 matches in, they get it done and now expect the inspectors to do the re-inspection. In time for their match. Right.

And, as soon as a team starts making modifications, an inspector should tell the head ref that their sticker is null and void. If they come out without the LRI confirming re-inspection, the whole alliance gets a Red Card. Ouch.

Oh boy....

As an inspector, I prefer to go out of my way to give the kids a good experience, not look out for opportunities to yell "Gotcha! Red card!"

[rich2202]

If I were an RI, and a team told me they planned to switch between Part A and Part B, I would have them weight with Part A, and then Part B, and note the weights next to a description of the part.

Then, when they came for subsequent reinspections, I would look for the part, check their weight, and if everything seems in order, note which is the current configuration/date/time, and clear them for competition.

That way, we know which is their last configuration when inspected, and if they show up on the field with the wrong configuration ... it is their problem.

[GaryVoshol]

Oh boy....

As an inspector, I prefer to go out of my way to give the kids a good experience, not look out for opportunities to yell "Gotcha! Red card!"

No intent of Gotcha whatsoever. In fact, this would be preventing the other 2 teams in the alliance from getting a Red Card, since they have absolutely no way of knowing that the transformer team's inspection was temporarily suspended. If the LRI and HR keep in constant communication, the Red Card will be avoided, not made easier to get.

[EricH]

No intent of Gotcha whatsoever. In fact, this would be preventing the other 2 teams in the alliance from getting a Red Card, since they have absolutely no way of knowing that the transformer team's inspection was temporarily suspended. If the LRI and HR keep in constant communication, the Red Card will be avoided, not made easier to get.

Aye. If a team isn't re-inspected, and this is known BEFORE the match, the OTHER side of T8 comes into play--the team doesn't participate in the match, including their HP. This gives only the team in question a Disqualification (Section 5.5.3, Part D) which assigns no points, rather than a red card. (A Red Card is a Disqualification, but a Disqualification is not necessarily a Red Card.)

And I agree, we're not out there to "Gotcha" teams. If it's a quick fix, I'd rather have the team fix it quickly than apply any sort of DQ or RC--just works out better.

[Al Skierkiewicz]

So here is the next edition of the list (based on the first two weeks)...
1. Please make sure you have your Bag and Tag paperwork with you when you drop your robot off for your event. Inspectors want to check it for accuracy prior to letting you open the bag and begin work at your event. If it is in the bag (not visible), in your mentor's back pocket (who is not coming) or on the workbench back at your build space, it is going to invoke a delay while we process the non-compliance form. Attaching it to the bag with a big, double handle paper clip works very well.
2. Teams have been bagging their robot with the battery in the robot and connected. This is pretty dangerous practice. When packing your robot for the next event, do not put your battery in the robot, please.
3. Inspectors need to see the electronics during inspection. Do not hide them or cover them with conformal coatings. Mounting them upside down is also difficult to inspect and unreliable for operation.
4. You must have the latest firmware installed on your robot. Under the current version of Inspection checklist, these are the versions you should have.
Driver Station – 08021500 or newer <R80> (Note the version number is a date in the format of, DD/MM/YY00)
roboRIO – v23 and 2.1.0f3 <R45>
Talon SRX – v.28 for PWM, v1.01 for CAN <R41, R59>
Jaguars – v109 <R59> for CAN
PCM – v1.62 <R60> if pneumatics are used.
PDP – v1.37 <R61>
Yes this is a repeat, but many of you didn't listen in week 2. The PDP CAN must be connected to the RoboRio CAN.
5. There are two fuses in the PDP. While they may appear to be fully inserted, they are often not. Please be sure to push them down firmly. The top of the fuse should be nearly the same height as the Weidmuller connectors that are mounted next to each one. When not fully inserted these to become intermittent, resetting the radio and/or the RoboRio.

As always, ask your LRI if you have any questions. Do not assume you know the answer. Good Luck everyone.

[ATannahill]

So here is the next edition of the list (based on the first two weeks)...
1. Please make sure you have your Bag and Tag paperwork with you when you drop your robot off for your event. Inspectors want to check it for accuracy prior to letting you open the bag and begin work at your event. If it is in the bag (not visible), in your mentor's back pocket (who is not coming) or on the workbench back at your build space, it is going to invoke a delay while we process the non-compliance form. Attaching it to the bag with a big, double handle paper clip works very well.
2. Teams have been bagging their robot with the battery in the robot and connected. This is pretty dangerous practice. When packing your robot for the next event, do not put your battery in the robot, please.
3. Inspectors need to see the electronics during inspection. Do not hide them or cover them with conformal coatings. Mounting them upside down is also difficult to inspect and unreliable for operation.
4. You must have the latest firmware installed on your robot. Under the current version of Inspection checklist, these are the versions you should have.
Driver Station – 08021500 or newer <R80> (Note the version number is a date in the format of, DD/MM/YY00)
roboRIO – v23 and 2.1.0f3 <R45>
Talon SRX – v.28 for PWM, v1.01 for CAN <R41, R59>
Jaguars – v109 <R59> for CAN
PCM – v1.62 <R60> if pneumatics are used.
PDP – v1.37 <R61>
Yes this is a repeat, but many of you didn't listen in week 2. The PDP CAN must be connected to the RoboRio CAN.
5. There are two fuses in the PDP. While they may appear to be fully inserted, they are often not. Please be sure to push them down firmly. The top of the fuse should be nearly the same height as the Weidmuller connectors that are mounted next to each one. When not fully inserted these to become intermittent, resetting the radio and/or the RoboRio.

As always, ask your LRI if you have any questions. Do not assume you know the answer. Good Luck everyone.
Al, you should have waited until after the update. The firmware requirement for the roboRIO was removed. The image must still be v23.

[Al Skierkiewicz]

Alex,
You are correct, the email telling me that a new inspection checklist was being published came while I was writing the above entry. The difference is the firmware version for the RoboRio. We have been informed by NI that all RoboRios shipped with one of the only two available firmware versions both of which are legal. It is suggested that if you have not updated your RoboRio, do not attempt to install a later version. The installed version will be legal.

[Al Skierkiewicz]

OK, This is going to be a short list for now as I respond to a post elsewhere and some of the reports coming in from regionals this weekend. I know I have said this before but please make sure everyone you know sees this.

Materials that are not safe or cannot be used on FRC robots.
1. Uncoated lead used for ballast. Even if your build location allows lead in it's raw form, if you plan on traveling, the lead needs to be sealed. You can paint it, dip it in tool handle coatings, you can even injection mold plastic around it. Many locations and venues list it as hazardous in it's raw form. If you are using sealed lead, it may not be machined, drilled, cut, etc. while at an event.
2. Mercury in any form. It is hazardous in this country and many other countries. Just shipping it requires specific methods and documentation. Small quantities may be handled differently depending on locale. R8 specifically disallows any switches or contacts that use mercury. If a team happens to spill mercury onto the field, it becomes a hazardous materials site.
3. Any ballast attached using duct tape, ty-wraps, or adhesives. Please think about what you are doing. If the ballast comes loose, your robot, other robots and people near your robot will receive the consequence of your actions. Ballast must be attached with known good fasteners, to the frame of your robot. Use of 1/4" hardware or larger, through the ballast and into the frame, is ideal. In some cases, stainless steel hose clamps may be sufficient but it is up to the LRI at your event to make that call. If the Head Ref or FTA see an issue, they may alert the LRI to check your installation again.
4. Anything that can spill onto the field is also not allowed. This means sand, ball bearings, shot, pebbles, or water or anything else that you can think of.

[IndySam]

Al are you saying a small dumbbell weight (2-5lbs) attached to the frame of a robot with zip ties is some kind of a hazard and would not be allowed?

[Alan Anderson]

Al are you saying a small dumbbell weight (2-5lbs) attached to the frame of a robot with zip ties is some kind of a hazard and would not be allowed?

He has said before that zip ties are not a structural fastener. That's what I told the team in Kokomo using them to hold on their hand-weight ballast. One student suggested that they could attach the weights with duct tape instead...

I did a quick tug test and didn't think they were a problem in that case, so I didn't ask an inspector to review it. In a more collision-prone game, I definitely would have done so.

[Thad House]

I get the zip tie thing, but at the same time I don't. The field is held together with zip ties and Velcro, and it seems to work just fine. As long as you buy good quality zipties, they could easily hold a robot together.

[Alan Anderson]

The field is held together with zip ties and Velcro, and it seems to work just fine.

Velcro holds the field to the carpet, and there's quite a lot of square yards of the stuff doing it. Good luck getting that much holding area on a robot.

Zip ties on the field are used for wire management, not structure. Unless you're talking about the lexan side panels on the original field design, in which case you might be interested to find out that several of them do break on average every event, and they have been replaced with rivets in the new design.

[Jon Stratis]

I get the zip tie thing, but at the same time I don't. The field is held together with zip ties and Velcro, and it seems to work just fine. As long as you buy good quality zipties, they could easily hold a robot together.

The only parts being held together on the field by zip ties are the Lexan covers (NOT structural, these are intended for shielding and to provide a smooth playing surface). In those cases, the physics are well understood - most of the force against those covers will come from head-on collisions with robots, in which case they are pushed against the pipes supporting them. Sliding force has been known to break zip ties on the field, and they are replaced as needed. Additionally, if those zip ties break and the Lexan comes lose, it's not exactly moving - it just flops to the ground. The structural elements to the field (all the aluminum piping) is held together by slotting pieces inside of each other and locking them in place with pins. There is a firm mechanical joint between every part of the field structure, and it's designed so it can only come apart in a very specific way.

Contrast that to a weight attached to a robot. The weight is constantly experiencing acceleration and deceleration as the robot moves around. It can take an impact from another robot, in which case this is two robots hitting each other, not one robot hitting a stationary target. If the robot is spinning in a circle full speed when the zip tie lets go, the weight isn't just going to fall to the floor - it's going to be thrown across the field (and possibly outside of it). This is a much more dangerous situation.

[Al Skierkiewicz]

Scott,
Yes.
Anyone who does not think high speed collisions are not possible should have been at a friendly scrimmage/practice I attended yesterday. One of the robots had a "software" glitch and drove across the field at full speed into the player station.
Thad, I can assure you that zip ties are not rated for dynamic loads and are known to fracture under a variety of conditions, most of which are present during FRC matches. If you watch the field as closely as some of us, you will have noticed the FTA or FTAA running back to the field box and pulling out ties to replace those broken by robots every day, every event.

[Mr V]

Velcro holds the field to the carpet, and there's quite a lot of square yards of the stuff doing it. Good luck getting that much holding area on a robot.

Zip ties on the field are used for wire management, not structure. Unless you're talking about the lexan side panels on the original field design, in which case you might be interested to find out that several of them do break on average every event, and they have been replaced with rivets in the new design.

In last year's field zip ties and gravity were the only things holding the high goal and its support structure above the heads of the drive team. This year the tote chute's ramp and cover are held together by zip ties and gravity. From my understanding the original AndyMark fields did ocassionally break the rivets that held the polycarb panels which are a structural element in the AM field. I believe that they uprated the rivets used in the production versions because of this.

The only parts being held together on the field by zip ties are the Lexan covers (NOT structural, these are intended for shielding and to provide a smooth playing surface). In those cases, the physics are well understood - most of the force against those covers will come from head-on collisions with robots, in which case they are pushed against the pipes supporting them. Sliding force has been known to break zip ties on the field, and they are replaced as needed. Additionally, if those zip ties break and the Lexan comes lose, it's not exactly moving - it just flops to the ground. The structural elements to the field (all the aluminum piping) is held together by slotting pieces inside of each other and locking them in place with pins. There is a firm mechanical joint between every part of the field structure, and it's designed so it can only come apart in a very specific way.

Contrast that to a weight attached to a robot. The weight is constantly experiencing acceleration and deceleration as the robot moves around. It can take an impact from another robot, in which case this is two robots hitting each other, not one robot hitting a stationary target. If the robot is spinning in a circle full speed when the zip tie lets go, the weight isn't just going to fall to the floor - it's going to be thrown across the field (and possibly outside of it). This is a much more dangerous situation.

There are zero pins holding the traditional field together this season. Last season there were a hand full of pins used to keep the high goal together but not to keep it supported above the driver's head. The shelf that the high goal structure sat on was attached to the driver's station uprights by zip ties. Yes the shelf had semi circle notches that kept them centered on the upright and served to transfer the load, however without the zip tie it would have been very possible to bump it in a manner that could send the entire structure crashing down. Yes those zip ties were heavy duty, rated for 150lb load IIRC and there were several, but still zip ties were an integral structural element in last year's design. With the impacts the driver's station wall saw last season I was always a little afraid of what could happen during one of those sever impacts. It was normal for the field to grow a couple of inches over the course of an event due to those impacts. I saw many cases where a substantial lump formed in the carpet behind the driver's station due to the impacts stretching the carpet.

I do not know for certain if there are any pins in the AndyMark field because I have only seen the flyer and not seen one in the flesh.

[FrankJ]

Another Q&A A welcomed clarification of the solenoid pressure rating rule. Pretty much any industrial valve with a rated working pressure over 100 psi should meet this.
R446 (https://frc-qa.usfirst.org/Question/446/r66-d-a-solenoid-valve-rated-for-a-maximum-working-pressure-that-is-less-than-125-psi-versus-a-relief-valve-set-to-a-lower-pressure-than-the-maximum-pressure-rating-according-to-the-manufacture)
Q. R66(D), a solenoid valve "rated for a maximum working pressure that is less than 125 psi" versus a relief valve "set to a lower pressure than the maximum pressure rating". According to the manufacturers we have contacted and NFPA definitions MWP and MPR are 2 unrelated requirements. A valve is safe up to its MPR but only rated to "work" (the solenoid would actuate the valve normally) at it's MWP. If the MPR is >125 (ours is 215) is it acceptable without additional relief? Our MWP is 115.
2015-03-04 by FRC2973
A. Thank you for the question. This is legal, and the language will be updated in the Game Manual in Team Update 2015-03-17 to be consistent with this answer.

[IKE]

I get the zip tie thing, but at the same time I don't. The field is held together with zip ties and Velcro, and it seems to work just fine. As long as you buy good quality zipties, they could easily hold a robot together.

Emphasis was mine. Often when writing a rules for any sort of sanctioning, the ruless have to written in such a way that if to prevent something dangerous from happening, it is inspectable. For example, in amatuer racing, roll cages are often specified at Steel, of a particular diameter and wall thickness with an inspection hole. While not all steel is created equal, the lowest common denominator is used and specified to ensure that at a minimum the cage should be safe.

As most of us know, Zip-ties vary in quality and strength by a very large range. Do I think you can find Zip-ties that could handle impact loading... Yes. Do I think I can tell the difference between those and "junk ones"... NO (or at least not easily).
A simple McMaster Carr search shows 15 varieties of cable ties with a wide range of ratings. It is also worth noting that with plastics, just because it was originally rated at 100 lbs strength does not mean it will always be that strong. Some plastics degrade with humidity. Other plastic degrade with UV light exposure.
At the end of the day, there is just too high of variation which is why you get the pushback.

Does this mean you will never see a robot with a dumbell ziptied to the back? Doubtfull. It does mean though that once it gets noticed, it will likely be asked to be correctly anchored.

I would still be very impressed if a team showed me the calculations for the resultant G loading of a 10 feet per second robot hitting the wall, the documents that show the cable tie rating, and the calculations and safety factors that make them believe it is OK.*

*for a 10 FPS robot with bumpers that compress 2" ideally it is around 10G. If you assume about 0.25" of deflection it is nearly 100G. Thus a 10 lb dumbell might exert 100 to 1,000 lbs. of force on those restraints.

[Paul Boehringer]

Hi Al,

Three questions. My team is considering a tethered ramp.

1.) Is the q & a still open for questions? (If so I would like to ask the following there for official confirmation)

2.) Would it be legal to put some velcro or something similar on the bottom of the ramp so it will stay in place?

3.) Would it be legal to use a passive suction cup (just stick it on before a match) to stick to the wall by the chute door?

Thanks for this thread.

[notmattlythgoe]

Hi Al,

Three questions. My team is considering a tethered ramp.

1.) Is the q & a still open for questions? (If so I would like to ask the following there for official confirmation)

2.) Would it be legal to put some velcro or something similar on the bottom of the ramp so it will stay in place?

3.) Would it be legal to use a passive suction cup (just stick it on before a match) to stick to the wall by the chute door?

Thanks for this thread.

Yes to #1.

Probably not legal for #2.


R5 Traction devices may not have surface features such as metal, sandpaper, hard plastic studs, cleats, hook-loop fasteners
or similar attachments. Traction devices include all parts


Richard beat me to the rule #.

You might want to look at this (https://frc-qa.usfirst.org/Question/442/g17-d-indicates-that-robots-cannot-be-attached-to-field-elements-would-a-rubber-suction-cup-stuck-to-the-human-player-wall-by-the-robot-wall-be-considered-a-violation-of-this-rule) for #3.

[Richard Wallace]

2) see R5 and G16 (blue box item a.)

3) see G16(d)

[Alan Anderson]

From my understanding the original AndyMark fields did ocassionally break the rivets that held the polycarb panels which are a structural element in the AM field. I believe that they uprated the rivets used in the production versions because of this.

Some of the riveted connections on the single original prototype field failed during a FIRST-supervised stress test, when a robot was intentionally and repeatedly slammed into the field wall after it had survived an off-season competition. That's the kind of thing prototypes and stress tests help find. The production field design addresses that weakness and others (plus a few small cosmetic/convenience features).

There are zero pins holding the traditional field together this season.

The connections between the year-specific corner walls and the rest of the field are still the same sort of drop-in tubing "pin" that has always been used on this size field. That interface isn't likely to change as long as the old welded fields are still in regular use.

There are also indeed still zip ties holding things together on the year-specific parts. That too is unlikely to change unless a catastrophic event occurs because of them...or unless the Robot Inspectors get authority over the field. ;-)

I do not know for certain if there are any pins in the AndyMark field because I have only seen the flyer and not seen one in the flesh.

In addition to the structural pins I already mentioned, very small pins are used to help keep the alliance wall polycarb panels from flexing or vibrating out of their slots.

[Al Skierkiewicz]

Thank You Richard and Matt. You quoted the appropriate rules in my opinion.
I believe the Q&A will remain open until Champs.