Chief Delphi - pic: Bumper Handles

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pic: Bumper Handles

Re: pic: Bumper Handles

I love the idea, but I'm concerned about legality in the face of picky inspectors. That's not part of a standard bumper cross-section, nor is it attachment hardware used to attach the bumper to the frame perimeter. Your handles basically don't have anything to do with bumper functionality. You couldn't get away with attaching a sensor system or motor to your bumpers (to save weight) and claim it was part of your attachment system.

I'd Q&A those handles and have a back-up solution worked out, unless running without any handles is acceptable.

Re: pic: Bumper Handles

I also love the idea. This would make loading and unloading the robot safer and easier. However, if your handles are mounted to the bumper, are your bumpers mounted to your frame securely enough to lift the robot? A good, secure bumper mount might not be load-bearing enough for this application.

Re: pic: Bumper Handles

Quote:

Originally Posted by Cothron Theiss (Post 1552189)

I'd argue the other way. If I wouldn't want to lift a robot by the bumpers, they're not secure enough for FIRST Stronghold.

Edit: That said, I concur that they do not comply with the bumper rules. The rules constructively specify that bumpers are for protection, secure attachment to the chassis, and alliance color and team number designation. Any part of the bumper that does not provide one or more of these functions should not be part of the bumper. If the same parts which fill these functions just happen to provide additional functions, that's OK, but it's hard to see how lift handles fill any of the required bumper functions.

Re: pic: Bumper Handles

Handles are good! although you might want to attach them to the robot itself, instead of the bumpers. We try to integrate handles into our robots if possible, or attach them to the frame if we can't find an elegant place for them.

This year, they are part of the skid rails on top of the robot...if you look close, you can see the finger holes in the polycarbonate cover.

Re: pic: Bumper Handles

The bumpers passed inspection this last weekend event and we used them all weekend. They were great. My view was that they make lifting the robot safer. Also if its not listed as illegal than they are legal until they say something. If they say something than we can easily remove them. We usually build the handles into our robot design but with going under the low bar it did not leave room for them. We had this Idea for last year but funny that we could not use them.

Re: pic: Bumper Handles

Quote:

Originally Posted by joeweber (Post 1552313)

Also if its not listed as illegal than they are legal until they say something.

With BUMPERS, it's the opposite, since R21 says "BUMPERS must be constructed as follows:". The specifications that follow make no mention of lifting handles.

Re: pic: Bumper Handles

Quote:

Originally Posted by joeweber (Post 1552313)

Also if its not listed as illegal than they are legal until they say something.

What cgmv123 said. Here's the entirety of that rule to remind you:

Quote:

R21 BUMPERS must be constructed as follows (see Figure 4-7):
A. be backed by ¾ in. (nominal) thick by 5 in. (± ½ in) tall plywood or solid, robust wood. Small clearance pockets and/or access holes in the plywood backing are permitted, as long as they do not significantly affect the structural integrity of the BUMPER.
Particle board or chipboard is not likely to survive the rigors of FIRST Robotics Competition gameplay and thus not compliant with R21-A.
B. hard BUMPER parts allowed per R21-A, R21-E, R21-F, and R21-G must not extend more than 1 in. beyond the FRAME PERIMETER with the exception of minor protrusions such as bolt heads, fastener ends, rivets, etc (Figure 4-5 and Figure 4-7).
C. use a stacked pair of approximately 2 ½ in. round, petal, or hex “pool noodles” (solid or hollow) as the BUMPER cushion material (see Figure 4-7). All pool noodles used in a BUMPER set (e.g. Red set of BUMPERS) must be the same diameter, cross-section, and density (e.g. all round hollow or all hex solid). Cushion material may extend up to 2 ½ in. beyond the end of the plywood (see Figure 4-8). To assist in applying the fabric covering, soft fasteners may be used to attach the pool noodles to the wood backing, so long as the cross section in Figure 4-7 is not significantly altered (e.g. tape compressing the pool noodles) All pool noodles used on a ROBOT must be the same in order to maintain the desired interaction between ROBOTs in the cases of BUMPER-to-BUMPER contact. BUMPERS containing pool noodles of vastly different construction may cause a “ramp” effect when interacting with other BUMPERS.
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. The cloth must completely enclose all exterior surfaces of the wood and pool noodle material when the BUMPER is installed on the ROBOT. The fabric covering the BUMPERS must be a solid Red or Blue in color. The only markings permitted on the BUMPER fabric cover are the Team number (see R28) and hook-and-loop backed by the hard parts of the BUMPER.
Visually, the Red or Blue must be as close to the corresponding color in the FIRST logo as reasonable (i.e. to a reasonably astute observer, they appear similar).
E. optionally use aluminum angle, as shown in Figure 4-6 or other fasteners (e.g. staples, screws, etc.) to clamp cloth.
F. Optionally use aluminum brackets (i.e. angle or sheet metal) to attach BUMPER segments to each other (see Figure 4-6).
G. must attach to the FRAME PERIMETER of the ROBOT with a rigid fastening system to form a tight, robust connection to the main structure/frame (e.g. not attached with hook-and-loop, tape, or tie-wraps). The attachment system must be designed to withstand vigorous game play. All removable fasteners (e.g. bolts, locking pins, pip-pins, etc.) will be considered part of the BUMPERS.

There's nothing in there about making lifting the robot safer. Your handles aren't part of your rigid attachment system. If the handles were integrated with the cloth cover in some fashion, they'd pass, but they're clearly different material that's been added on to act as handles.

Bumpers are meant to act as bumpers and bumpers only. You're given a certain allowance of FREE weight and space to add bumpers to protect your robot. The rules are so strict here because there's a history of leveraging that free allowance to gain an advantage. More weight is more pushing power, so teams would make bumpers as heavy as possible. I think 3847 is responsible for the wording about not compressing the noodles. They made a set of highly compressed bumpers that probably cushioned collisions much less, but gave them a distinct advantage in pushing matches, as they would wedge under uncompressed bumpers. Just this year, the GDC almost made any velcro at all on bumpers illegal. A pointed Q&A modified that ruling to allow velcro backed by hard bumper parts, but we nearly ended up with a LOT of illegal bumpers in FRC. And so on.

By your own admission, you're gaining an advantage with your bumpers unrelated to their purpose. You have handles on your robot that you otherwise wouldn't have. Yes, you may have passed an inspection with them, but "It passed at my last event." is not going to persuade an inspector that notices you have illegal bumpers. It certainly never persuaded me when I saw something illegal on a robot. Also, it's your responsibility to follow the rules to the best of your knowledge. Inspection determines gross legality, but there's any number of ways you could violate the rules and still be 99% certain to pass inspection. So. You've got a few opinions that your bumper mods aren't legal. You might want to post a Q&A to determine whether they are or not.

Re: pic: Bumper Handles

At the LRI Training, I discussed the need for handles on all robots with Frank as a safety issue. I think we need them and my team regularly uses either a set of fixed handles, or eyebolts in the frame that we snap lifting strap handles to. It makes controlling the robot much easier and safer and keeps the CG lower for better control. One of the other inspectors reported that he had a robot dropped on his head while sitting at the inspection station table!

With having to go over the wall to the secret passage and other elements to get on or off the field this year, lots of kids are going to be tripping while carrying robots. We need handles!

Having said that, however, I believe putting them on the bumpers will get you into trouble and your inspector should not have approved them for the reasons given above, mostly that they don't meet the description of a legally constructed bumper. In addition, I think you may have created a potential for other robots to snag and get hooked on your handles since they are outside the frame perimeter.

Re: pic: Bumper Handles

Quote:

Originally Posted by joeweber (Post 1552313)

The bumpers passed inspection this last weekend event and we used them all weekend.

Past results do not indicte future performance. Just because your inspector missed them doesn't mean they're OK.

That being said, thank you for clarifying that they can be removed easily enough.

Re: pic: Bumper Handles