Aluminum angle on bumpers

[Magnechu]

Is there any limit to how much you can have? Or can you just put it on the corners? Our bumpers only weigh 12.5 pounds, so we want to add another 5 pounds onto them in order to maximize our weight at the bottom of the robot to have an even better low center of gravity.

Any and all help is appreciated!

[Russ Beavis]

You could use steel angle instead to add weight. You can add whatever material you'd like in that 1" deep "hard parts only" zone.

Russ

[MrForbes]

I was thinking about this...we might need to reduce the length of our plywood bumper backing if we add angle, to keep the hard parts from extending past the bumper perimeter on the adjacent side, that is, into the corner.

[ZakuAce]

I've been smacking my head on the wall about this. What is the point of the aluminium? Last year we just stapled the cloth in place. I know it isn't really my place to contridict the allmighty GDC, but I'm flipping out about this because it is making my job of building the bumpers somewhat more complicated. Also, it says to attach the aluminium with wood screws, but won't the screw heads stick out a bit from the bumpers? Or do the screws go in from the top of the bumper, in which case the plywood has a better chance of cracking from the screws?

Argh, I wish this hadn't been thrown on me so late in the game. Oh well.

[EricH]

FYI, http://forums.usfirst.org/showthread.php?t=11394 says those angles are optional.

[ZakuAce]

:O Now I feel dumb. Thanks a lot, that helps. Disregard my sillyness, we're hectic here over other things.

[dlavery]

Originally Posted by Russ Beavis

You could use steel angle instead to add weight. You can add whatever material you'd like in that 1" deep "hard parts only" zone.

Russ

That is definitely NOT the case. You CANNOT add "whatever material you'd like" in the "hard parts only" zone. Please do not do this!

If there is any question about what can or cannot be incorporated into the bumpers, please be sure to ask that question on the official Q&A forums. Remember, any answers found here (including this one) are unofficial and will not carry any weight with the inspectors.

-dave


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[Russ Beavis]

Dave,
My understanding of the rule is that, as long as there are the 2 stacked noodles + durable cover that's securely fastened to a 3/4" thick x 5" tall plywood backing, there is no reason why teams can't add a 1/8" thick steel plate all around the plywood. That was the rationale behind my "add whatever material you'd like" comment (emphasis on "add").

Russ

[Mike8519]

Perhaps the point Dave is trying to make is that you cannot add whatever you want inbetween the robot and bumper if it is non-functional from an attachment point of view?

But.... if your multi-part bumper attachment system (R08-H) uses thick steel brackets for strength there is no reason why that is illegal.

[GaryVoshol]

Originally Posted by Mike8519

But.... if your multi-part bumper attachment system (R08-H) uses thick steel brackets for strength there is no reason why that is illegal.

Unless we are to interpret Figure 8 - 1 as a definition, whereas Figure 8 - 2 is only an example.

[MrForbes]

Gary--that might be the case, because

<R08> ...... BUMPERS must be constructed as described below and illustrated in Figure 8 – 1.

The angle shown in Fig 8 - 1 is labeled "aluminum", not "steel", and it does not appear that the angle is optional...???

Time for me to read up on more Q&As....

edit: apparently the angle is optional

http://forums.usfirst.org/showthread.php?t=11394

[GaryVoshol]

As opposed to

I. BUMPERS must protect all exterior corners of the BUMPER PERIMETER (see Figure 8 - 2).
J. Corners and joints between BUMPER segments may be filled with short pieces of vertically oriented pool noodle, by wrapping the pool noodles around the corners, or by beveling the ends between adjacent segments so they form a tight and complete protective surface (see Figure 8 – 2).

And, as you've found in Q&A, the clamping brackets are optional. (Although an earlier post http://forums.usfirst.org/showthread.php?t=11219 said they are required; that's OK, the GDC can change.) If 8 - 1 is to be definitive a note indicating the brackets are optional should be added.

[MrForbes]

Exactly!

[Magnechu]

So are steel brackets okay or not?
I'll try and ask on the Q&A but what do you all think?

[AlexD744]

I know we could add weight by sticking steel robs in the noodles. It's brilliant. jk.