Al's 2016 Inspection Thread
 

Well,
It is that time again and there is a lot to consider. It seems that teams all over the world are having some issues with bumper rules this year. It matters little whether they are rookies or veterans. So here goes my first installment...
1. Bumpers are required to cover all external corners of your FRAME PERIMETER for at least 8 inches, measured from every corner of your frame. R19. This means all corners, no exceptions and the measurement is the frame backing the bumper segment, not the bumper segment.
2. If your FRAME side is less than 8" long, then the entire side must be covered by bumper.
3. Bumpers are noodles covered by rugged cloth attached to a backing board and mounted on the FRAME PERIMETER of your robot in the BUMPER ZONE. Anything that does not meet this criteria is not a bumper. Backing board not covered by noodles and fabric is not a bumper. Metal that is attached to your bumper but is not covered by your bumper system is not a bumper.
4. Bumpers may not move during a match and the BUMPER ZONE will be evaluated by your robot inspector while your robot is sitting flat on the floor of the pit during inspection.
5. Bumpers are not part of the robot for withholding allowance or for Bag and Tag rules. However, they are part of your robot when it is "On Stage". Don't you want your entire robot to look great? Take the effort, you have time.
6. There are Team Updates every Tuesday and Friday, many of which have changes to the Robot Rules Section 4. Your inspectors will be evaluating your robot based on the latest Team Update and/or the latest revision of the Inspection Checklist, now at Rev. 1.1 https://firstfrc.blob.core.windows.n...-checklist.pdf
7. There are many threads about team numbers here on CD. Team numbers (numerals only, please) must be on your bumpers per R28. The Q&A has been very specific, all parts of the numerals must meet the specification of 1/2" stroke.
8. Bumpers do not have to be at the same height all around your robot. The front bumper can be higher than the back bumper. But, all bumper segments have to reside in the BUMPER ZONE between 4" and 12" above the floor when the robot is sitting on the floor.
9. Bumpers are two, stacked pool noodles, per Figure 4-7. Bumpers are not one noodle, one and half noodle, shaved noodles to reduce diameter, cutouts in the backing board(s), fabric with no noodles, or any other creative interpretation of Section 4.7.
10. Bumpers are designed to keep you playing in a game that is likely to produce agressive interaction with other robots. We want you to play every match you are scheduled for.
Good luck everyone.

Re: Al's 2016 Inspection Thread
 

Thanks Al.

Bumpers are bumpers, it's shouldn't be this hard!

Re: Al's 2016 Inspection Thread
 

Al, do you know how the RI's would determine if a bumper fabric is considered rugged or smooth enough?

Re: Al's 2016 Inspection Thread
 

Poke it with a screwdriver? :D

I'm curious about this as well. I've never actually been asked about the durability of bumper material before.

Re: Al's 2016 Inspection Thread
 

With 2 years of rookie teams(~700 IIRC) that have never made bumpers, for some people it IS challenging.

Re: Al's 2016 Inspection Thread
 

This is a good question. We used the AM slick material, and it is significantly thinner than the standard Cordura fabric. Considering it's sold specifically for use as bumper material, I'm confident it's legal, but it'd be nice to make sure that all RIs are on the same page with the thinner fabric.

Re: Al's 2016 Inspection Thread
 

Same here.

Re: Al's 2016 Inspection Thread
 

I usually run the pointy end of a nail across the fabric and see if it rips - jk.

It can be hard to tell. There are some really light weight durable fabrics out there. Expensive, but that is their choice. I usually let the LRI know.

The issue usually resolves itself rather quickly. If it rips during bumper to bumper contact, it isn't durable enough. At some point, you won't be let back on the field until the bumper is fully repaired (not just patched with fabric tape).

Re: Al's 2016 Inspection Thread
 

D. be covered with a rugged, smooth cloth. (multiple layers of cloth and seams are permitted if needed to accommodate R27, provided the cross section in Figure 4-7 is not significantly altered).

Silk or bedding are not considered rugged materials, however 1000D Cordura is. Tape (e.g. gaffer’s tape) matching the BUMPER color is allowed to patch small holes on a temporary basis.

This wording of this rule is intentionally wide to permit cloth available in different parts of the US and internationally. The 1000D Cordura is my cloth of choice and the basis for comparison of other fabric. Inspectors have seen teams try to use a variety of fabrics over the years. Many held up in battle and many did not. In general, if you can see through it, if it is intended for clothing or it available in flowered patterns as well as solid colors it is likely not to survive this game. The smooth refers to fabrics that have woven in features like corduroy, etc. I believe the intent is to prevent you robot from getting caught (by the bumper fabric) on field pieces, borders and other robots.
If your fabric is the type used in laptop cases, back packs and luggage, it is likely to survive inspection and the game.

Re: Al's 2016 Inspection Thread
 

I'm a little disappointed in the AM bumper material. Just in practice we have managed to rip the fabric :(

Re: Al's 2016 Inspection Thread
 

You are correct. I am from the old school, no bumpers generation.

No bumpers 2004 Youtube

Re: Al's 2016 Inspection Thread
 

Which kind?

Re: Al's 2016 Inspection Thread
 

I assume this is the slick material. Do you have any pics you can post?

Re: Al's 2016 Inspection Thread
 

G19 ROBOTS may not intentionally detach or leave parts on the FIELD.
Violation: FOUL. DISABLED if structurally non-compliant or the Team number or ALLIANCE color is
ambiguous.
This rule is not intended to penalize ROBOTS that encounter accidental
breakage (e.g. a failed MECHANISM that falls off), as those actions are
not intentional.
G19-1 ROBOTS must be in compliance with Section 4 (4.7 BUMPER Rules) throughout the MATCH.
Violation: DISABLED

Teams, be aware also of Update 13 (which came out yesterday). See bolded font above. Build your bumpers ROBUST and NEAT! No more hanging/dragging or otherwise loose fabric dragging outside the bumper zone.

Re: Al's 2016 Inspection Thread
 

This. Back in 2013. Ultimate Ascent. Our team's reversible bumper material was dragging outside the bumper zone when we went for our 10point climb/hang. So, our bumpers dragging the ground when the rest of the robot was hanging cost us the match/quarterfinal round at South Florida that year.
This year it looks as if the rule will DISABLE your robot entirely for the rest of the match. Yikes! keep those bumpers ON clean everybody!

Re: Al's 2016 Inspection Thread
 

Team Update 13: Violation: FOUL. DISABLED if structurally non-compliant or the Team number or ALLIANCE color is ambiguous

I will have to think about what "failures" would be structurally compliant. Drooping fabric. Anything else?

Re: Al's 2016 Inspection Thread
 

Don't get Big Al started on the elastic bumper covers!!!!!!! I don't think he was too keen on them :eek:

Re: Al's 2016 Inspection Thread
 

We ripped ours too just practicing, no robot-robot contact, although we are using the standard RoboPromo stuff that came in the KOP.

Re: Al's 2016 Inspection Thread
 

Checking the interweb:

The Robopromo super slick material is a 70 Denier Nylon

The AM Slick is a 200 Denier Nylon

Re: Al's 2016 Inspection Thread
 

Al,

Just out of curiosity, wouldn't it be less than 16" (8" from EACH of the vertices)?

Re: Al's 2016 Inspection Thread
 

Technically although Al was just quoting the manual there.

Re: Al's 2016 Inspection Thread
 

In 2013 our robot hit a defensive robot pretty hard (not by 2014 standards though) and not one, not two, but all four bumpers fell off at the same time. Don't be that robot.

Re: Al's 2016 Inspection Thread
 

R19 ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 8 in. of BUMPER must be placed on each side of each out side corner (see Figure 4-3). If a side is shorter than 8 in., the entire side must be protected by BUMPER (see Figure 4-4).

Re: Al's 2016 Inspection Thread
 

This is one of the biggest faults of the bumper rules. It's very unhelpful for R19 to repeat that the entire side <8" must be protected by BUMPER, when earlier statements make it obvious that this MUST be the case for rules-compliant bumpers with sides <16". The poorly worded statement is probably causing misinterpretations and mistakes. But unfortunately it's been repeated around FRC for so long that it might be ingrained at this point.

Re: Al's 2016 Inspection Thread
 

We ripped our bumpers up on Saturday at the Week Zero event using the AM slick bumper material. The fabric cut right along the edge of the plywood. The small lexan walls on the batter were what caused the rips since it is so easy to drive up on top of them.

We are going to remake them using the tougher cordura and put thin aluminum angle along the bottom edge to protect the fabric in accordance with the rules. I would highly recommend teams consider doing this before you end up with a serious tear like ours.

Re: Al's 2016 Inspection Thread
 

Nate,
Think from the other side of the discussion...
"If I can't cover 8" from the corner than I don't have to use bumpers on that side."
That is one thing the GDC does not want. In the past this dimension has often been 6". This year due to the game, the dimension was changed to 8". In my opinion it is pretty obvious that was decided to give a greater challenge to designers.

Re: Al's 2016 Inspection Thread
 

Al,

I just checked the manuals from 2012 until now and they had the minimum set for 8". Maybe I'm missing what you are saying but it would appear this rule has been set like this for awhile.

Re: Al's 2016 Inspection Thread
 

It's been 8" for a long time.

The other point trying to be made is that there is no configuration of a 16" or shorter side that doesn't require the entire side to be covered. It is the logical consequence of 8"from each corner needing covering. Another way to say it is that all frame sides greater than 16" require at least 16" of total bumper on that side in addition to the 8" from each corner.

The wording of the rule for "sides less than 8"" could also be written "sides less than 16"" without changing any actual bumper requirements.

Re: Al's 2016 Inspection Thread
 

"Long time" is a relative term when you have been around since 1996. The rule was 6" in 2011.

Re: Al's 2016 Inspection Thread
 

I disagree the minimum side is 16". I propose that a side that is 8" long, completely protected by bumpers has bumpers 8" from each vertex. The minimum side is essentially 8" not 16". Of course the other side of each of those vertexes also need a minimum 8" of bumper.

The <8" being completely covered wording was intended to address the "infinite vertexes" case of a circular robot.

I suspect the confusion arises from FRAME PERIMETER sides with concave segments. I agree that a side with a concave segment (aka intake throat) needs a minimum of 16" of fully supported bumpers.

I would also suggest that the term FRAME perimeter is confusing and should be changed to CONVEX PERIMETER or string perimeter. Wheels sticking out past the FRAME are still part of the CONVEX perimeter.

Re: Al's 2016 Inspection Thread
 

My understanding is that the "shorter than 8 inch" rule was placed there to explicitly allow sides shorter than 8 inches (and require that they have bumpers). Without this rule, you couldn't have a (for example) four-inch long side because you could not then put 8 inches of bumper extending from each corner without violating other bumper rules limiting extension of hard and soft parts away from the frame perimeter.

Re: Al's 2016 Inspection Thread
 

It also covers cases where a robots side is less than 8". I've seen teams cut the corners off their ROBOT to help with frame perimeter issues, leaving a side of 1-3". Fully cover that side, plus 8" on the other sides of each of those corners along the longer sides.

Re: Al's 2016 Inspection Thread
 

I think that the manual needs to have more bumper pictures after R19. Particularly, it needs one showing a side that is less than 8" that has legal bumpers on it. The bottom right corner of robot C should also be split into a couple of pictures, because there is too much happening there right now to clearly see why specific aspects of that configuration are illegal.

Also, another term should be added to the glossary to differentiate what we conventionally think of as a "side" and a side as determined by the frame perimeter. Perhaps FRAME PERIMETER SIDE would suffice.

Re: Al's 2016 Inspection Thread
 

Maybe differentiate a side from a segment of a side (for sides with gaps)? Maybe outlaw circular bumpers and require "organic" convex perimeter shapes to be made from >8" segments of bumper with supporting 8" rigid frame? I vote for CONVEX PERIMETER to replace FRAME perimeter (which I believe is a major source of the confusion) Given the large number of redundant Q&A, the intent is clearly not easily conveyed.

Re: Al's 2016 Inspection Thread
 

I think most of the bumper confusion is teams trying to fit the rules to their robot rather than the robot to the rules. The 2011 rules had the effect that the minimum frame segment was 6" since the minimum bumper length was 6 inches. IE no round robots. Gaps in bumpers were not allowed in 2011. I think the current rule phrasing came about from changes that allows bumper gaps & round robots. Better phrasing might be segments less than 16" require full bumpers and segment greater than 16" require 8" from each vertex since that is the effect of the current rule.

Re: Al's 2016 Inspection Thread
 

I liked the 2013 version of this rule (as clarified in a team update) that essentially said the required 8 inches wraps around the next corner for sides shorter than 8 inches (see attached image). It's the essentially same rule as this year's, but it would have stopped most of the BUMPER questions this season.

Attachment 20194

Re: Al's 2016 Inspection Thread
 

OK, time for part 2 for those of you at your first event this weekend.
1. Pneumatics. Not much has changed here from previous years although there are a number of new devices that people will be using. Please remember that all pneumatic parts must be COTS in an unmodified state (except certain exclusions listed in R76). That means no painting!
2. You may not make your own pneumatic parts. That means you may not make an extendable arm using pressure inside a PVC pipe. While it maight be cool, it does not meet the rules.
3. One and only one compressor under RoboRio control. I know you think you have ways around this rule because "air is air". There is no way around this rule. The compressor can be on the robot or it can be off the robot. You can't charge your robot with one compressor and then have another compressor on the robot for the match. No shop compressors charging the system, no exceptions. No FRC legal compressor being run directly from a robot battery while you are in the queue to pre-charge your robot. No larger volume compressor being run from a car battery.
4. The tubing you use must be 0.160" maximum inside diameter. This is not a safety item, this is part of the restriction on max available power. Inspectors are being trained on how to recognize the larger tubing.
5. If you use pneumatics there are certain items that must be present. One of those is a Nason pressure switch, P/N SM-2B-115R/443. No others are allowed and this must not be modified in any way. (They aren't adjustable anyway)
6. When using pneumatics, you must have a calibrated Pressure relief valve connected via legal rigid fittings (e.g. brass, nylon, etc.). A calibrated valve will release air when the system stored pressure is above ~125 psi. These are very easy to calibrate, it requires two wrenches and an alligator clip. Loosen the locking ring on the valve (that is the little hex nut closest to the threaded portion of the valve). Short the pressure switch terminals with the clip and enable the robot. The compressor will run continuously. There is a small hole at the top of the valve. When system pressure reaches 125 psi, some air should be released from the small hole. If no air is present, turn the top hex fitting counter clockwise until air is released. If air is released at less than 125 psi, then turn the hex fitting clockwise to stop the release of air at less than 125 psi. When calibrated, hold the top hex fitting and tighten the locking nut. This is not a precise or repeatable calibration. A correctly calibrated valve will release air between 125 and 130 psi on a repeatable basis.
7. No White Clippard tanks P/N: AVT-PP-41). If you found tanks in your robot inventory and don't know if they are these tanks, just believe they are and get rid of them. The explosion hazard is well documented.
8. "Three way valves" are now legal. these are typically known as one way valves in that air moves in one direction and when released, the pressure flows through a third port to atmosphere.
9. Compressors get hot.Do not place wiring near the compressor be careful to keep pneumatic tubing away from the hot parts as well. Tubing will swell and then fail (with a loud pop) when heated and pressurized.
10. Don't modify pneumatic parts. I am restating this so you don't paint them, obscure part numbers, make scratches, dents or drill into them. You may not drill "lightening" holes in any pneumatic part. Do not drill out and tap cylinders to accept larger fittings. Do not add mounting holes and do not try to modify manifolds to get one more output port.

Re: Al's 2016 Inspection Thread
 

Al,

Thanks for all your hard volunteer work for FRC!

I may have found a discrepancy in the Inspection Sheet regarding the Driver Station Number. The IS says 16.0.2 but the NI website only shows 16.1.0.

I am not in front on the control system at home so I cannot compare the numbers on the Driver Station but these don't look right.

I will attach a pdf.

Re: Al's 2016 Inspection Thread
 

The current version that will show on the Driver Station is 16.0.2
So that's what you will compare to when inspecting.

The label on the NI download is incorrect, but is the latest 16.0.2 version.

Re: Al's 2016 Inspection Thread
 

Mark,

Thanks for checking up on this so quickly.

Re: Al's 2016 Inspection Thread
 

Al could you comment on regulators? For the primary regulator

Does that mean A)don't adjust the working pressure higher than 60 PSI or B) regulator capable of being set higher than 60 PSI are not legal. Keep in mind the KOP recommended regulator fits in group A but not group B.

This post is also relevant to the question.

As always thanks for you input.

Re: Al's 2016 Inspection Thread
 

Am I correct in my understanding that this valve or this valve meets those requirements?

Re: Al's 2016 Inspection Thread
 

Just to further clarify... Although the download from NI is named FRCUpdateSuite_2016.1.0.zip, once installed the software identifies itself as version 16.0.2 if you look at the display on the driver station.

Re: Al's 2016 Inspection Thread
 

Marc,
The Inspection Checklist was updated when the software changed to be compatible.

Justin,
I believe those are the valves which prompted this change in the rules. Provided that they do not violate any other robot rules.

Although this is not an FRC endorsement, simply my opinion. The product line you point to from Automation Direct has some pretty cool stuff in it.

Re: Al's 2016 Inspection Thread
 

AM now sells other white air tanks, but does not mention whether they are Clippard. Is it ONLY the P/N AVT-PP-41 tank (which I believe is labeled as such) that is illegal?

Re: Al's 2016 Inspection Thread
 

Yes. Only the white tanks with green Clippard writing are illegal. Any white tank sold by AndyMark now is legal as are the black Clippards.

Re: Al's 2016 Inspection Thread
 

Sorry I have been away from CD this week as I attended the Duluth Regionals. So I have a few things to remind teams of following that event.

1. What is a robot side? Well it is the frame that exists between two exterior corners as determined by the "string test". If you wrap a string or tape measure around the FRAME PERIMETER, a side is between two corners. If your robot is rectangular then it has four sides. If your robot is "U" shaped to pick up balls, then the side that has the opening is one side, not two. If the distance from one outside corner to the next is less than 8", then the entire side must be covered in bumper. In no case can a bumper segment (as determined by the backing) be less than 8" long.
2. If your made bumper segments that are less than 8" long, you will have to change them to comply. Teams that have smaller FRAME PERMIMETERs can achieve this with a change in the frame aspect ratio to allow a wider frame segment on each side of the opening of the ball pickup.
3. Teams that are using tank track kits will have a challenge meeting the bumper rules. The front and back of the track needs to be covered by bumpers but they do not have to be at the same height. All bumpers must be in the BUMPER ZONE, the 4-12 inches above the floor.
4. Bumpers need to be backed up by frame as the rules specify. This is a challenging one for teams, but this game is very rough on robots and improving your frame and bumper attachments will go far in keeping you playing throughout the season.
5. Hard parts on the bumpers can only extend outside the FRAME PERIMETER by 1 inch. If you are using drywall screws to attach your bumpers, most will exceed the 1" rule. The end of the screw will damage your bumpers and other robots, and may injure your team members. You will be asked to show your bumper attachment during inspection. #12, 3/4" screws work great if you don't have a better attachment worked out. They are available everywhere.
6. MDF, HDF, chipboard and paper board are not "solid, robust wood". 3/4" plywood is best, but hardwoods in the 3/4" dimension work as well but are more expensive. 5 inch +/- 1/2" is the height rule for the backing board.
7. Teams are having many issues related to electrical. If you haven't seen the game played, I can tell you going over any defense is hard on robots. Please check all electrical connections but in particular make sure the battery, PDP and main breaker connections are tight. If you crimp your own #6 terminals, then use a crimper meant for that service. Some terminals can also be crimped in the corner of a vise in a pinch. When done correctly, the wire will not move around in the terminal and you will not be able to pull the wire out of the terminal. The severe shock robots receive this year cause brownout conditions on loose electrical connections.
8. Check other wiring, particularly power wiring to RoboRio, PCM and VRM modules and all CAN buss wiring. Give every wire a "tug test" to insure the wire doesn't pull out. I found more than 20 robots this weekend that had one or more loose connections. Most often teams have simply not stripped the wire long enough for the push terminals to grab the wire.
When in doubt on anything, come over and ask the LRI or other inspectors for advice or assistance. Small problems become huge on Friday afternoon or Saturday morning.

Re: Al's 2016 Inspection Thread
 

Thanks again Al for this annual thread!

Who would have imagined that Bumpers would have such a big part in this thread? One year without them and many forget how important they are.

Electrical robustness is indeed huge this year. If you have a questionable connection somewhere in your machine, this game will expose it, and likely at the worst time possible!

Re: Al's 2016 Inspection Thread
 

I can't emphasize this enough.

I was the FTAA for the Kettering University District this past weekend and there were a lot of instances of teams losing connection with the field because of radio and roboRIO power issues.

Specifically I would add the following:

1. Make sure the power connection plugged into your radio is secure. There were many cases where teams encountered mild to large impacts and had their radio either reboot (which takes a good 60 seconds to reconnect to the field) or lose power entirely. My personal choice for this is hot glue as you can still peel it off by hand if you need to, but just make sure it's secure.

2. Standard consumer-grade Velcro is not sufficient to secure small electrical components. There were several robots that lost radio/roboRIO power because components came loose during a match. There was even one match where a team's radio ended up disconnected and on the field. Please make sure you're using robust attachment methods - zip ties can work ok in a pinch, but hardware is usually the best method.

Al,
Question for you regarding the "dump" valve on pneumatic system.
Does it matter if the valve is before or after the regulator? Ie on high pressure side or low pressure side, as long as it completely vents all pressure from system.
I couldn't seem to find a rule that dictates placement. Closest I could find was R83 stating the only devices that "may" be on high side.

Re: Al's 2016 Inspection Thread
 

R89 Any pressure vent plug must be:
A. connected to the pneumatic circuit such that, when manually operated, it will vent to the
atmosphere to relieve all stored pressure in a reasonable amount of time, and
B. placed on the ROBOT so that it is visible and easily accessible.

When you place it downstream from the regulator is takes longer to release all pressure so that is why most people put it upstream.

My team couldn't pass inspection due to being on low side. When the students questioned this the inspector just walked away and wouldn't listen to reading of rules or reason.
Personally I don't think it matters one way or the other, but in the name of safety it is safer on the low side in my opinion.

Re: Al's 2016 Inspection Thread
 

Two things would have helped the majority of teams at San Diego this year...


1. Read AND UNDERSTAND the bumper rules
2. Update your driverstation software

This is the advice I sent to all the SD teams as their LRI...

DRIVER STATION UPDATE
Team update 12 included an update to the Driver station software. Your driver station MUST be updated before you can compete in San Diego. Please update your software before you come to the competition.

https://decibel.ni.com/content/docs/DOC-46527

COST ACCOUNTING WORKSHEET
Every team must show a completed Cost Accounting Worksheet (we used to call them your Bill of Materials) in order to pass inspection. You can find a suggested format attached. Please have this filled out before you come to the competition

INSPECTION WORKSHEET
Want to get through inspection quickly? Have a look at the attached inspection checklist for the rules you must comply with before you will be allowed to compete.

BUMPERS
Make sure your bumpers are compliant with Section 4.7 Bumper Rules in the Game Manual. If you think there might be a problem, be sure to bring the appropriate material and parts to correct your bumpers at the competition. You must have legal bumpers (both red and blue) before you can compete.

Re: Al's 2016 Inspection Thread
 

R89 requires the vent valve release all pressure in the system. If the regulator is set to 0 pressure, a low (working) pressure vent will not vent the high pressure (stored) side.

Re: Al's 2016 Inspection Thread
 

I noticed a discrepancy in interpretation between myself and another inspector at my event last weekend with regard to what counts as 'automotive motors' and since I will be inspecting at several more events this year I'd like a bit of clarification.

To qualify as an automotive motor, does it have to be a production part on a vehicle. In the interest of cost savings, is there any reason an aftermarket part that is intended for the same function would not be acceptable?

Are power lift gate motors considered door motors? What if these vehicles are referred to as 5 door models (hatchbacks).

If we cannot remove a COTS gearbox from the window motor, can we do so on other automotive motors? What if you could buy that motor without the gearbox? What is considered integral to the mechanical integrity of the motor?

Perhaps this would be better on Q&A, but since it doesn't really impact my team I wasn't going to request we ask it there.

Al's 2016 Inspection Thread
 

Ok I'll bite, why would the regulator be set to zero?
My point is the rule is open to not only interpretation, but also becomes a matter of opinion. The rules don't say must or shall be on the high side, but rather says must have one.
We had one that infact did empty the system completely, he just didn't like it on the low side, and seeing as there is no rule that says must be on high side it became his opinion.

How are teams going to be able to figure out what one persons opinion is going to be?

Re: Al's 2016 Inspection Thread
 

That's why teams ALWAYS have the right to appeal to the LRI. I know as an LRI, I will walk a team through any rule in question and make sure they understand why the ruling is the way it is. Most, if not all, of the other LRI's I know will do the same.

It's unfortunate, but it's practically an impossibility to properly train every inspector for every situation they may encounter when looking at a robot. I always tell my inspectors that if they aren't 100% positive about something, they need to come get me. If a team has a problem with a ruling, the inspector need to come get me. It makes it a busy day for me (50k steps during the 3 days at the Duluth regional alone!), but that's why I'm there!

Re: Al's 2016 Inspection Thread
 

That's usually the case, but not always. If you have working-pressure accumulators, for whatever reason, it can easily take less time to release if your dump valve is on the low side of the primary regulator.

Part of the issue is that the students don't want to come off as rude by pushing back against the inspector.
Don't want the proverbial target on their backs for the rest of event.
I was unable to be at the event this weekend, and would have pushed back and asked for LRI to come to pit had I been there.
They were able to replumb the system with the help of another team, but that time spent was really wanted to be spent on the practice field or in practice matches.

Re: Al's 2016 Inspection Thread
 

I can understand not wanting to be rude, and it can be difficult to come off gracious while tSelling an inspector he's wrong. I suggest a simple wording of "we've interpreted that rule differently, would you mind getting the LRI for a second opinion?" Train your students on that, and you should be golden :)

That is my plan for this weeks meetings. I really rather not have to bring legal counsel to the events. Lol

Re: Al's 2016 Inspection Thread
 

The best way to not seem rude is to ask the inspector which rule they are enforcing when they request something. Then look up the rule and see if they are correct or if it is a difference of interpretation. With the rule book in hand, feel free to discuss the inspector's ruling.

Most differences can be worked out with the rules in hand.

Re: Al's 2016 Inspection Thread
 

When in the pit & I don't want to dump the air out of the accumulators, but i don't want an actuator moving. Or if I want to release pressure on a cylinder. I will grant that the normal case is to have some working pressure, but you asked for a reason. Some teams have a lot of stored pressure. In that case it is fairly important to have the dump on the high side. In other cases maybe not so much.

I was not your RI. I do not walk away from questions & am always willing to review the rules and the reasons for my interpretation. I try to read the rules not as I what I would like, but what I think the GDC intends. Which is generally pretty literal. I will also suggest that they ask the LRI if they don't like my answer.

Re: Al's 2016 Inspection Thread
 

So be sure to label it a rear door motor?

Re: Al's 2016 Inspection Thread
 

As an inspector I love it when the students show me I'm wrong. It's a great learning experience for both of us.

Re: Al's 2016 Inspection Thread
 

If you change the setting of the Pressure Regulator, wouldn't that be a reason to be re-inspected to make sure the robot is in compliance with the pneumatic rules?

So is it safe to say based off of the responses that it is in fact legal to have the dump valve either on the high or low side?

Re: Al's 2016 Inspection Thread
 

Depends on where the regulator is in the system.
For instance, we've had robots that adjust the pressure on the fly.
What made them safe is the adjusted regulator was a secondary regulator downstream from the 60psi max regulator, so it couldn't have pressure greater than 60psi under any circumstances.

Re: Al's 2016 Inspection Thread
 

No. That is an adjustment not a modification. If you replaced the regulator with a different model regulator then that would be an modification that would require re-inspection. When checking robots in the queuing line, one of things inspectors look at is the air pressure.

Re: Al's 2016 Inspection Thread
 

This is why it's important to have quality bumpers.

https://goo.gl/photos/kiyM4gCH4qp42hXKA

Shall I take it no one wants to make an actual ruling on this?

Re: Al's 2016 Inspection Thread
 

I would rule it has to be on the high pressure side based on R78.

R78 If pneumatic COMPONENTS are used, the following items are required as part of the pneumatic
circuit and must be used in accordance with this section, as illustrated in Figure 4-15.

Figure 4-15 shows the dump valve on the high pressure side of the system.

Re: Al's 2016 Inspection Thread
 

Keep in mind although I inspect, I am not the GDC, Al, or even a LRI so mine is just an opinion. Q & A would give the official answer. I read to rules to mean on the high pressure side assuming the regulator is not off board (no storage pressure on the robot) for reasons previously stated. I see the other side of the argument & would cheerfully refer it to the LRI if it was an issue for the team. I also think it is a minor thing with little impact on safety and no competitive advantage.

Re: Al's 2016 Inspection Thread
 

IMHO, as long as the Dump Value empties the entire system within a few seconds, it would be ok on either the high or low pressure side.

Thanks for all the input on this.

Re: Al's 2016 Inspection Thread
 

I submitted the question on where the vent needs to be to Q & A. It is question Q933.

Re: Al's 2016 Inspection Thread
 

Thanks for doing that, Frank.

When I was a Lead RI, we had weekly conference calls with the Chief. Current LRIs I know tell me they still do that now. Several of them read CD frequently, so I expect that my Lead RI for this week's event will be able to give a ruling on vent valve requirements, should that question come up while inspecting a robot.

Before hearing from my LRI, my own opinion is the same as Richard Sisk's, based on my reading of R78 and Fig. 4-15. After I hear from my LRI, that could change.

I understand where you are coming from, but it is an example. My point is if the rule doesn't explicitly say it is open for interpretation, or opinions which leads to issues.

Similarly there is no official rule on where the main breaker has to be, and for the rule book to say "strongly recommend" doesn't mean has to be.

It becomes frustrating when others don't "feel" that the breaker or dump valve aren't in the correct place. If the rules aren't going to be explicit about such things then how can teams "fail" inspection? It's kind of like trying to say something isn't art.

Re: Al's 2016 Inspection Thread
 

Most of the inspection rules, especially those that are left to interpretation, are about safety. Make it easy on yourself and your inspector - unless you have a very specific reason, just follow the recommendations. When you deviate from recommendations, have your "plan B" figured out beforehand (e.g. the recommended part already in the pit and a plan to install it). The example here is one - what's the big problem with just putting the vent plug on the high side?

Re: Al's 2016 Inspection Thread
 

The rule on the main breaker isn't "strongly recommend".

It's "must be". I will grant you that "quickly accessible" is a judgement call on the part of the inspector... But I can't think of a way to word such a rule as to remove judgement from the equation. All robots are designed differently, and a location that works on one won't work on another. The bottom line with this rule is how you want the event staff to handle your robot should it start smoking - pull out the fire extinguisher and give your electronics a dousing, or kill power quickly and safely? One way you'll likely be back on the field for your next match. The other is a huge mess.

Honestly, I've never had a problem getting a team to move their main breaker or vent plug valve to someplace more accessible. They all seem to understand the safety reasons (at least, the mentors do) for it and comply quickly and willingly.


Now, I have to ask... why is it such a big deal to have the vent plug valve on the low side? What do you get from that that other teams don't get by having theirs on the high side? Why not just hook up the pneumatics similar to figure 4-15 like everyone else to begin with? You seem to be very adamant about this, yet your robot has already been changed to have it on the high side...

Re: Al's 2016 Inspection Thread
 

It takes noticeably longer to move air from the low-pressure side to the high-pressure side through the recommended regulator than from high to low. If there is air stored at working pressure, putting the vent on that side lets the pressure be released faster.

Re: Al's 2016 Inspection Thread
 

What was "on the low side"? You have the right to call in the LRI at your event for a decision and they all have my contact info to ask about a ruling they are unsure of. If your pressure was low, was it at the output of the regulator or was the storage pressure too low? In the case of the working pressure being low, that is within the legal limits. A team can set the pressure to whatever they want as long as it does not exceed 60psi. However, many valves get flaky at lower pressure.
If the "storage pressure" was low, was the compressor turning off? If not, you had a significant leak.

It isn't an overly big deal at this point. I was just wanting al to say it has to be on the high side, or it doesn't matter. In all reality it doesn't make a difference where the valve is located as long as the system is emptied in a timely fashion.

Now what's a timely fashion?? Our robot has two tanks, so it takes very very little time.

As for the breaker. I was referring to the blue box about the label saying breaker here.

The pressure release valve was on the low pressure side of the regulator in the system.

Re: Al's 2016 Inspection Thread
 

Their vent plug was on the low pressure side of the regulator.

It just hit me that the point of it will vent faster if on the high pressure side doesn't exactly hold true. If teams were to have the accumulator tanks on the low side for whatever reason the stored air would have to flow back through the pressure regulator as well. I have seen regulators that only operate in one direction. That is to say air won't flow through from the regulated side to the supply side, which would prevent the system from being completely emptied.

Re: Al's 2016 Inspection Thread
 

The regulator is required to be relieving, per R82, for exactly that reason. When high pressure is released in this case, the low pressure side would be vented through the regulator.

Agreed. Was just bringing up the fact that some do not vent both ways. But the fact of the tanks being on the low side and having to vent back through the regulator and it "taking time" still applies.
My biggest reason for continuing this debate is so I can have something to show my students after the fact. I strive to not just teach them how parts fit, and or interact, but also how to question things when needed, and that if you ask several people the same question you will get several different views. Not saying mine is right, or wrong and the same for the others that have posted, but rather different ways of looking at it and the importance of being able to do so constructively.
I do thank you all for all your views and comments, our team is actually going to devote about a half hour to this topic and how to interact with the inspectors in a constructive manor. You all have provided me with more info and knowledge to pass along than most might realize.

Re: Al's 2016 Inspection Thread
 

But the relieving regulator will stop relieving when it reaches the working pressure set point, correct?

That I have never tested. But I don't believe it will hold pressure on the working side like you thinking it may. Time for a test !!

Re: Al's 2016 Inspection Thread
 

Merely being a relieving regulator wouldn't necessarily be enough. A relieving regulator vents to atmosphere when performing its "relieving" function. Every regulator I have seen on an FRC robot does let air flow in reverse when the input pressure is lower, but nothing says it must do so.

While I've never actually encountered one in the wild, I know there are regulators that don't care whether the "high side" pressure is lower than the "low side". Such a regulator would maintain the working pressure even after the stored pressure part of the system was emptied. <R89A> would make it illegal to put the vent valve on its stored pressure side even though the regulator satisfied <R82>.

Re: Al's 2016 Inspection Thread
 

I do want every team to know this. If you question an inspector's decision, it will not be held against you. If it does, I want to know about it. You have every right to ask the LRI at your event for ruling and to explain the rule he is using to make his decision. If there still is a question, the LRI is instructed to give me a call or text. If I cannot be reached, Jonathon Bryant should be called, and after that Frank Merrick. All the LRIs have my number and Jonathon's.

Re: Al's 2016 Inspection Thread
 

Thanks for this Al! I know in the past my kids have been hesitant to push back. One year at QCR the RI wanted them to completely rewire the main breaker in order to relocate it because he felt it was not easy to access. They were getting ready to start moving it, when I walked up and stopped them and asked for an explanation. He pointed out the restrictions. I agreed that it wasn't the best place, but it was protected and where he wanted it was not. Additionally his hands were giant so of course he would have problems that none of us had. I asked for the LRI to make a ruling and she simply asked us to make it more visible by placing the main breaker stickers around the location.

We were gracious and non-confrontational about it, which is the key when questioning/pushing back against what you think is within the rules.

Al's 2016 Inspection Thread
 

Well the answer is in from gdc. Does not matter if on high or low as long as rest of R89 is met.

Now word just had to be spread so other teams and inspectors are aware.

Re: Al's 2016 Inspection Thread
 

If a team questions my call, it doesn't bother me if they ask for the LRI's opinion. If I am overruled, I learn something in the process.

Most times, if it would cause a lot of hardship to fix, I will ask an LRI for their opinion. I don't want a team to do a difficult fix if they don't have to. I also would rather have the LRI take the heat, rather than me :yikes:

Re: Al's 2016 Inspection Thread
 

That's why we get paid the big bucks :)

Re: Al's 2016 Inspection Thread
 

IIRC, LRI pay consists of a very condensed trip to Manchester, generally during a snowstorm. And maybe some donut priority at events.

The black vests do not contain asbestos or kevlar. But they do have a lot of pockets. :)

Re: Al's 2016 Inspection Thread
 

Wait a minute... Donuts? I've been underpaid for years!

Re: Al's 2016 Inspection Thread
 

Wait no Kevlar, talk about risk. :D

Re: Al's 2016 Inspection Thread
 

And they are very hot even in Minnesota.