[DFTF] Bumper Tips...

[Coach Norm]

We have used 1/4" Hole Grip Cleco clamps to hold our bumpers on for past three years. They work extremely well. You will need Cleco pliers as well to remove the Clecos.


We attach a small piece of aluminum angle to the bumper. The angle has a 1/4" hole drilled to match the KOP chassis frame holes.

In the past we have made two sets of bumpers.

[Tristan Lall]

Use good-quality hardwood plywood. It's pretty dense (more free weight) and very durable. You could easily use it to span large gaps in the structure (even though the 2012 rules limit this).

I've often used it as a structural member—it's very stiff and tough, so it makes a good outer frame rail reinforcement, when properly supported. The actual outer rail can be relatively lightweight as a result.

Use some sort of quick-release mechanism. FIRST says it should take at most 10 min to change bumpers; I say each bumper segment should take no more than 10 s, and design accordingly. (This is useful in the elimination rounds.)

Originally Posted by Cal578

I did not see anything in the bumper rules prohibiting other materials or parts such as Great Stuff. I wouldn't use it structurally, but using a little to just hold the noodles to the plywood seems like a great idea (it's amazingly sticky). I don't think you'll get any advantage by trying to fill the empty space. In the end, the fabric will really be the main method of holding the noodles to the plywood.

For our prototype bumpers, since the fabric wasn't ready yet, we just used some industrial "Saran wrap" to hold the noodles to the wood. Quick, cheap, easy, works great. That alone is not ready for collision events, but it's good for testing the design. When the fabric covering is installed, we can trim off any exposed plastic, and we'll be good to go.

You should probably ask the Q&A about using materials not specifically listed. In the past, that's typically been impermissible, but this year's interpretation may vary, because of some changes in the way the rule is presented.

[artdutra04]

For quick and easy swapping of bumpers, nothing is easier than using using studs and hairpin cotter pins. 228 has used this method since 2009, experimenting with different methods of alternately having the studs attached vertically to the robot frame or having them attached horizontally to the bumpers, depending on the bumper configuration.

As long as you don't lose any of the cotter pins, you can swap bumpers in 20-30 seconds.

Here's a photo of 228's 2011 robot with the bumper mounts in the background.

[Brandon Holley]

Joe-

I believe Great Stuff would not be legal, but is an interesting idea. Maybe worth a proposal to the GDC for next season.

I would recommend making two sets of bumpers for changing colors. We tried the reversible bumper and while it worked, we found it to be a little more cumbersome than a nicely designed quick change set.

I would also encourage you to continue on the path towards a bumper set that is a total of one or two pieces. I'm partial to the two piece "U" assembly which is basically like two c's sliding on from each side and connecting in the middle.

Pulling the fabric tight helps to hold the noodles in place, and with the angled aluminum, the fabric will not tear after repeated impacts.

-Brando