BUMPERS ARGHHH!!!!

[RoboMom]

http://www.chiefdelphi.com/forums/sh...60&postcount=1

Another potential resource.

[lanigirl1019]

what are y'all using to fasten the bumpers to the robot??

[Bigflip2073]

http://www.chiefdelphi.com/forums/at...2&d=1233599363

Would attaching a brace to the outside of the bumper backing make any difference?

[powerkane]

if your talking about conectingg two boards to gether then putting the noodles horizontal acrost the board and one vertical at the corner thenn wrapping it all in fabric it is fine but your boards have to run the lingth of the robot so if it gets hit it will not break off your brakets but i sugest you do it all sepprate so it is easier to get in to your electrical from the side if you need to but i dont know what your bot looks like so i cant realy tell you how to build them but your idea will work just fine. i hope thats the answer your looking for

[EricH]

Bigflip, the proposed brace location would not be legal. If it's outside the backing, it's either a) dangerously close to the 1" limit in <R08-N> and violating <R08-O>, or it's out by <R08-O> due to this Q&A.

powerkane, check <R08-O>. You can't put the backing into the corner areas.

[jgraber]

Originally Posted by 2166BlueBotics

It sounds like you are thinking about doing something like this

http://www.chiefdelphi.com/forums/at...2&d=1233599363

If that is the case, I got this response from the Q&A about it

My interpretation of this is NO, you may not use a brace if you intend to permanently attach it to the bumper assembly. I came up with a solution to make a brace using "soft" parts of the bumper only. I can model it and post a picture here if you would like.

My meaningless vote is with BigFlip. I have a pending Q about it, something like this: is there a limit to how far inside the robot perimeter the bumper part of a bumper bracket may extend? Is there a limit to the number of bumper segments that may attach to one bracket?
Until overruled by tonight's conf call, or the Q&A, I intend to have two solid horizontal left side plywood braces whose edges are coincident with the robot perimeter but extend inward above/below the frame, and permanently attach the bumper segments to it. This will stiffen the frame as well. Attached with bottom bolts through the bottom/frame/tee-nuts in top brace.

Bumper weight: my prototype 48" x 5" x 3/4" oak plywood weighs about 3 lbs. With two full length noodles and fabric, about 4.5 lbs. This represents the weight of all left side bumper segments, so I have 4.5 lbs of margin to add braces, staples/glue to hold fabric, bolts, t-nuts, screws, etc, per side,
to add up to 18lbs.
I imagine I'll have to leave an inspection flap at the corners to show the inspector that the bumper segments meet point to point at the corner without intruding into the corner. Since this is stock frame, I'll have to have pockets drilled in the bumper backing for the axle bolts, which makes the robot perimeter a little fuzzy.

18lbs of bumpers seems like a lot compared to some fancy milled aluminum 3 lbs frames I read about here...

The top edge of the bumper needs much more bracing than the bottom,
given the bumper zone is not centered on the stock frame.

[powerkane]

i is pwned i need to read the rules sorry i was just sayin that it is a good design tho

[MrForbes]

Bumper weight....I seem to recall some teams in past years having trouble making the bumpers meet the maximum weight limit, because they built them as shown in the drawing in the rules, with aluminum angle on the the back corners to hold the fabric to the wood. Perhaps that's why the weight limit was increased from 15 lbs to 18 lbs?

[EricH]

http://forums.usfirst.org/showthread.php?t=11771

Please note, however, that this is specifically for the bumper part of a multi-part attachment system. I would assume that it goes for non-multi-part systems as well, but use caution.

I'm wrong in my previous post, I think. The way I now interpret this is: it depends on what you define as "outside". If it's relative to the center of the robot, my interpretation stands. If it's inside the backing from that point of reference, then it's legal.

The correct interpretation seems to be: if it's inside the perimeter, you're good, otherwise, you're not.