Bumper help
 

I have cut 3/8'' plywood down to size, but I have recently found out that our bumpers have to be 3/4" plywood
do you recommend me either gluing or nailing two 3/8'' pieces together to form a 3/4" piece?

also, are you guys just using hex bolts to attach your bumpers to your chassis?

Re: Bumper help
 

You are not allowed to make your own plywood/laminate, according to Q&A. Sorry.

Re: Bumper help
 

The bumpers, especially in this game, are going to take a LOT of punishment... You'd have to cut additional 3/8 pieces anyway so I'd suggest you just start over with 3/4. You wouldn't want them breaking apart during competition. That might disqualify your team. After all that work it wouldn't be worth the risk.
I you just HAVE to use 3/8"... glue AND nail them.

My 2 cents

Steve

Re: Bumper help
 

Yeah, you'll have to start over again with a new piece of plywood. I know that is probably fustrating :mad:

Re: Bumper help
 

If you can, try and find something with at least seven plies. Three and five ply are not as strong. We usually try and use 3/4 T & G flooring plywood.

Re: Bumper help
 

We used hex bolts to attach our bumpers last year going straight into the KOP frame and it was a real pain. Whenever we had to remove the bumpers for inspection or working on the robot, and put them back on, it was not fun fiddling with nuts inside the chassis channel.

This year, we're attached L-brackets to the bumpers and have bolts that go vertically through the top and bottom of the KOP chassis channel and tighten down with wingnuts, and so far it has been so much easier to work on. I would recommend putting the effort in to make bumpers that are easy to remove and reattach.

Re: Bumper help
 

Brackets attached to the bumpers themselves are a non-standard construction and not allowed. You may have brackets attached to your frame, which are then used as the attachment point for a bolt that comes from the bumper. This is my opinion, and not official - please review <R08> and the various Q&A's regarding bumpers.

Re: Bumper help
 

There's a post in the Q&A regarding this. Mounting brackets are fine, but aren't part of the bumper, so they must meet the robot's size and weight standards.

http://forums.usfirst.org/showthread...t=bumper+mount

Re: Bumper help
 

Are we allowed to reuse bummers?
The bummers from last year are the same dimensions that we need for this years robot so it would save a lot of time, money and energy to just reuse them.

Re: Bumper help
 

Already been asked in the Q&A. The response was something to the effect of "bumpers are a fabricated item and therefore may not be salvaged from old robots."

Re: Bumper help
 

ohh ok, we weren't sure because they aren't included in the robot dimensions or initial weight. Thank you

Re: Bumper help
 

do u think trying to glue down the hex bolt to the plywood (or inside the plywood) is a good idea?

L brackets are a pain b/c they have to fit within the dimensions...and I doubt I have 1,5'' on the length and width to use

Re: Bumper help
 

Things like Blind Nuts work great for attaching bumpers.


http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXK019

The little tangs you see sticking up get pressed (re: Hammered) into the wood, and hold very well.
These require access to whatever you are mounting the bumper to from the other side, so because of this aspect, it may not work for everyone.