Tips from a veteran Robot Inspector

[EricH]

Originally Posted by wireties

Our bot pulls balls in on all 4 sides so we have small-ish bumper segments on the corners. Right now the numbers appear in order but with a gap on each side. Does that sound legal? Or would the complete number appearing across the corner work? The Q&As relevant to R35 are kinda vague. If you inspected our bot, what would you say?

TIA

If your number was split between the two bumpers, the Q&A is clear, at least to me. It's saying that you're going to be redoing the numbering to comply with the rules. I really wish they'd put it out in an Update, but it is what it is.

Game - The Robot » Bumper Rules
Q. We have a u-shaped robot, so will have split front bumpers. Can we split the our numbers; say "33" on the right and the "52" on the left or do all of the numbers need to be on one side of the robot? It may be a tight fit with the new number size criteria.
A. Per [R35], team numbers must be clearly visible. This means that they may not be inverted, obscured, fragmented, upside down, etc.

Game - The Robot » Bumper Rules » R35
Q. We are deciding to use a square U frame. So, we have to split the 4th bumper into 2 sections. Because of this, we can't decide how to place "3490" on our Bumper. Should we place the 4 numbers on 1 side, or should we split 34 and 90 across the Bumper. R35 doesn't explain how to handle this situation.
A. Per [R35] team numbers must be "clearly visible from a distance of not less than 100 ft, so that judges, referees, and announcers can easily identify competing Robots." Thus they may not be obscured in any way (disconnected, out of order, rotated, upside-down, mirror imaged, etc).

(emphasis mine)

So, no gaps, and I wouldn't go around the corner, either (too easy to construe as a gap in the number, or the wrong number altogether). But the GDC hasn't been asked about going around the corners yet, so that one might be an interesting one to see what they say.

[Al Skierkiewicz]

Keith and Joe,
The best answer would be to protect as much of the shooter (or any moving parts) as best you can. Field resetters, judges and refs aren't always robot team members.

[Al Skierkiewicz]

Next installment in the Al's Annual Inspection list. Thanks to Wayne for getting it started this year.

Bumpers.
Ok bumpers have been around for a while, they change a little every year but they are here to stay. You must satisfy all the bumper rules, not just selected ones. So here goes...
1. They must be backed by 3/4" thick plywood, 5 inches high. If you are not able to get 3/4" in your country then the nearest metric equivalent is OK. Pine boards and MDF are not allowed.
2. You must have two, vertically stacked 2 1/2" pool noodles. Color is not a consideration but they must not be modified by inserting round bar stock to add weight or shaped in any fashion to allow better functionality for your robot. Exception to this rule below.
3. Bumpers must be covered in strong fabric of red or blue color, closely matching the colors of the First Logo. 1000 denier nylon is recommended. You will need to change colors depending on which alliance you are assigned in any match. This means you either have a method of changing colors on one bumper system or you have two bumpers systems, one blue and one red.
4. You may add a 5" long piece of pool noodle in a vertical orientation to cover the corners of your bumper system. This is to insure that no hard parts of your robot or bumper is capable of contacting another robot or field parts. You may miter the corner pool noodles to accomplish this protection. See Fig 4-6 in the robot manual.
5. Bumpers must attach firmly to the frame of your robot, be able to be easily removed or mounted and all parts of the bumper system must remain inside the critical 2" to 10" above a flat floor. All sections do not need to be at the same height but they all must remain inside the bumper zone when mounted.
6. Bumpers need to have your team number displayed on four sides of your robot. The numbers need to be 4" high, 3/4" stroke and readable from a distance. Team numbers need to be white in color or outlined in white. If you are doing well, you want other teams to know who you are.
7. Small gaps behind the bumper system are allowed due to boltheads, fasteners and welds. However, bumpers only work when backed up by robot structure. So small spaces can be bridged by the bumpers but nothing greater than 8" long. See Fig 4-7 of the robot rules.
8. With this year's game, many teams will design their bumpers to have openings for appendages or ball handlers. That is OK as long as all exterior vertices are covered with a bumper section (backing board) of at least 8" in long on both sides of the vertice.
9. Your bumpers will be weighed separately at inspection so remove them but bring them with your robot to the weigh and size station. One complete set of bumpers must weigh less than 20 lbs. Both sets need to be weighed if you have a red and blue set.
10. Securely fastened to the robot frame means threaded fasteners, cleavis pin attachment or some other rigid form of attachment. Zip ties, duct tape, rubber bands or velcro do not meet the requirement of secure fastening.
There are several questions about bumpers on the Q&A forum, I suggest you search 'bumpers' on the forum and read them. You can find it here...
https://frc-qa.usfirst.org/Questions.php

[wireties]

Originally Posted by Al Skierkiewicz

Keith and Joe,
The best answer would be to protect as much of the shooter (or any moving parts) as best you can. Field resetters, judges and refs aren't always robot team members.

We put something like a "sneeze guard" all the way around the gear - should be safe now. Thanks for the advice guys!

[loyal]

If the plywood on a bumper measures 7-7/8" lets say, then when you add on the fabric and noodles, if the bumper now measures 8" would an inspector accept this as a legal bumper? Or think about discrepancies in measuring devices like a tape measure as apposed to a machinist rule. Just asking how exacting will a inspector be? I realize that 7-3/4" is totally to short but where would an inspector draw the line? an 1/8", a 1/16", a 1/32"? zero tolerance? Just asking

[rsisk]

Originally Posted by loyal

If the plywood on a bumper measures 7-7/8" lets say, then when you add on the fabric and noodles, if the bumper now measures 8" would an inspector accept this as a legal bumper? Or think about discrepancies in measuring devices like a tape measure as apposed to a machinist rule. Just asking how exacting will a inspector be? I realize that 7-3/4" is totally to short but where would an inspector draw the line? an 1/8", a 1/16", a 1/32"? zero tolerance? Just asking

The inspector should be measuring the frame backing the bumper you are describing to determine if it is 8", then measure the plywood to make sure it is 8" as required by R27. I'll be using an ordinary measuring tape and if it is at 8" according to my tape measure, then I would pass the bumper. I wouldn't consider 7-3/4" to be 8".

[remulasce]

I don't see why people interpret [R28] to be so restrictive. [R28-B] has the phrase "(e.g. plywood, fasteners, etc)", which clearly opens up other parts. [R28-E] likewise has "All removable fasteners (e.g. bolts, locking pins, pip-pins, etc.) will be considered part of the Bumpers." And [R28-F] mentions "structures", without any definition of a structure or what materials may or may not be used in a structure. When I see "e.g." (==for example) and "etc." (==and so forth), I definitely think the list is not exclusive.

[R28-B]

hard Bumper parts (e.g. plywood, fasteners, etc) may not extend more than 1 in. beyond the end of the Frame Perimeter(see Figure 4‑4).

The (stuffinparens) do open up other parts- as an adjective to the collection, "Hard Bumper Parts". Then a restriction is placed upon these "Hard Bumper Parts", which thus restricts all those other parts now included in "Hard Bumper Parts". It does not legalize all hard bumper parts.

If a rule specifically enumerated that all lasers in the bumper must be within 1" of the frame, it would still not legalize lasers.

You may be confused why time was taken to enumerate through these specific parts. For this, see [R28E], which specifically requires you to build something on your own. It's because of this stuff that broader restrictions are necessary.

Basically, everything in the bumper must be exactly as proscribed, except for that one part in which you must design your own mounting system. This could include hard parts (plywood, fasteners, etc), so there had to rule limiting hard parts. But because the rule proscribes a mounting system, it has to be just a mounting system, even if it seems strong enough to be part of the frame.

[Jaxom]

Originally Posted by loyal

If the plywood on a bumper measures 7-7/8" lets say, then when you add on the fabric and noodles, if the bumper now measures 8" would an inspector accept this as a legal bumper? Or think about discrepancies in measuring devices like a tape measure as apposed to a machinist rule. Just asking how exacting will a inspector be? I realize that 7-3/4" is totally to short but where would an inspector draw the line? an 1/8", a 1/16", a 1/32"? zero tolerance? Just asking

If both the frame behind the bumper segment and the plywood part of the bumper are 8" or more, they pass. If they're shorter than 8" I tell them to fix the problem, but if they're within 1/4" or so and haven't figured out that they can ask for the LRI to take a look I'd remind them. If they're a rookie team AND if it's going to be really hard to add the distance I'd be inclined to give them a bit of a break, and would recommend that to the LRI.

And I'm quite happy with the accuracy of my Stanley tape measure, thanks.

[martin417]

Originally Posted by Jaxom

If both the frame behind the bumper segment and the plywood part of the bumper are 8" or more, they pass. If they're shorter than 8" I tell them to fix the problem, but if they're within 1/4" or so and haven't figured out that they can ask for the LRI to take a look I'd remind them. If they're a rookie team AND if it's going to be really hard to add the distance I'd be inclined to give them a bit of a break, and would recommend that to the LRI.

And I'm quite happy with the accuracy of my Stanley tape measure, thanks.

Again, what problem? (ref my post above). The Q&A answer seems quite clear, if the bumper parts are described by (R28) they are part of the 8" requirement. The 2-1/2" noodle extension is described by (R28-C), so is therefore part of the 8". Nowhere does any rule state the the plywood backing must be 8" long.

[Jon Stratis]

Originally Posted by martin417

Again, what problem? (ref my post above). The Q&A answer seems quite clear, if the bumper parts are described by (R28) they are part of the 8" requirement. The 2-1/2" noodle extension is described by (R28-C), so is therefore part of the 8". Nowhere does any rule state the the plywood backing must be 8" long.

This is the problem:

[R27]

Robots are required to use Bumpers to protect all exterior vertices of the Frame Perimeter. For adequate protection, at least 8 in. of Bumper must be placed on each side of each exterior vertex (see Figure 4‑1, Figure 4‑2, and Figure 4‑3).

You can't count the material in the corner - you need 8" on each side of the exterior vertex of the frame perimeter. That means you need 8" of frame with 8" of plywood and 8" of pool noodles and 8" of durable cloth covering in front of it. That is the absolute minimum length a bumper section can be when attached to the corner of the robot. It can be longer - you can have another 1" of plywood hanging off the end of the frame perimeter (R28B), you can have "soft parts" of the bumper extend another 2.5" past the frame perimeter (R28C), and you can extend the bumper further down the frame perimeter away from the vertex (you can even have the entire length of the frame perimeter covered in bumper if you want!).

People keep trying to lawyer this rule, and have been for a long time now... it's written clearly, and your LRI will tell you to fix it if you have 5.5" of bumper with 2.5" in the corner - argue all you want that it meets the requirements for R27, you won't get your sticker until you fix it.

[martin417]

Originally Posted by Jon Stratis

This is the problem:


You can't count the material in the corner - you need 8" on each side of the exterior vertex of the frame perimeter. That means you need 8" of frame with 8" of plywood and 8" of pool noodles and 8" of durable cloth covering in front of it. That is the absolute minimum length a bumper section can be when attached to the corner of the robot. It can be longer - you can have another 1" of plywood hanging off the end of the frame perimeter (R28B), you can have "soft parts" of the bumper extend another 2.5" past the frame perimeter (R28C), and you can extend the bumper further down the frame perimeter away from the vertex (you can even have the entire length of the frame perimeter covered in bumper if you want!).

People keep trying to lawyer this rule, and have been for a long time now... it's written clearly, and your LRI will tell you to fix it if you have 5.5" of bumper with 2.5" in the corner - argue all you want that it meets the requirements for R27, you won't get your sticker until you fix it.

OK, I understand. As I said, I originally interpreted the rule as requiring the hard parts to be 8", but after reading the Q&A and (R28) I re-thought my interpretation. I now see that I should have also re-read (R27). That makes it all clear.

(By the way, our bumpers do comply, I was just trying to understand the intent, not "lawyer" the rules". I hate that term by the way, everyone need to understand the rules in all their nuance, because the GDC rarely answers a question in a way that removes doubt or adds much to clarity.

[Al Skierkiewicz]

Martin,
You have pointed out a common mistake when checking the rules. In the case of the Q&A the answer is referring to the bumper. Another part of the rules say that the bumper must be fully supported by robot frame.

[R33]
Bumpers must be supported by the structure/frame of the Robot (i.e. each end of the Bumper must be rigidly attached
to the Frame Perimeter, the gap between the backing material and the frame must not be greater than ¼ in. and no
section of Bumper greater than 8 in. may be unsupported). See Figure 4-7.

It is for this reason, I always add..."all bumper rules must be satisfied".

[45Auto]

Read R27 and R33.

You must have at least 8" of bumper on each side of the exterior frame vertices.

Bumpers must be supported by the structure of the robot, and rigidly attached at each end.

Do you really think you can rigidly attach 2 1/2" of pool noodle to the structure of your robot?

[Al Skierkiewicz]

Now that we are less than a week to Stop Work Day, (and since a new Inspection Checklist was released last night) it is time to remind all teams that robots need to be inspected before all competitions. As it appears that many teams are choosing pneumatics this year for some functions, let's start there.

1. The compressor used to charge the robot storage system must be an FRC legal compressor controlled by the Crio. If you choose to keep your compressor off-board, it still must operate under Crio control and all other robot rules must be followed.

2. Valves must meet the max volume spec of 0.32 Cv per R71.

3. Components may not be modified. This includes painting, grinding to remove weight, etc. You may remove the pin from a cylinder as long as the cylinder itself is not modified in the process.

4. Tubing can be a maximum of .160 ID and all tubing must carry a working pressure rating of 125 psi.

5. Working pressure must be supplied through one primary Norgren regulator at 60 psi. Working pressures less that 60 psi can be supplied through additional regulators downstream of the primary regulator.

6. The pressure relief valve is not calibrated from the factory. You must adjust it to open at greater than 125 psi. This can be accomplished by bypassing the pressure switch and adjusting the valve while monitoring the high pressure gauge. Be sure to tighten the locking collar and test again.

7. The pneumatic system will be checked during the "Power On" test portion of the Inspection Checklist on p2.

Please have several of your students and one mentor assigned to checking over the Inspection Checklist prior to sealing the bag next Tuesday. It will save you considerable time at your events. Remember that when you inspect early, you get to go into the practice fill in line and get some extra practice time on the field.

One quick reminder...The rules have changed this year for maximum size of the operator console. This is due to the ball return's size in the driver's station.

[R82]
The Operator Console must not exceed 44 in. long by 12 in. deep (excluding any items that are held or worn by the
Drivers during the Match).

[MrForbes]

Originally Posted by Al Skierkiewicz

2. Valves must meet the max volume spec of 0.32 Cv per R71.

Are all previous year KOP valves considered legal?