I was wondering if teams have begun testing different bumper materials following the 2025 rules. I’m fairly certain not many teams (if any) have posted any tests yet (could be wrong). I know our team will begin testing in the next few weeks, so I just wanted to see what other teams were up to (if you’re willing to share)!
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I will be doing a presentation tomorrow for the Medtronic Foundation about new bumper options and rules. I have three samples prepared:
-one of standard materials and construction (backer rod/noodles, Baltic Birch ply),
-one of “cheap” newly legal materials (1/2"OSB, recycled foam floor tiles),
-one of “performance” new materials (1/2" UHMW, Flotex, 2# UVA, 3# cross linked PA).
Two of the options are shown in the photos above. None are tested but frankly I think there are things we can intuit that will help build better protection going forward. I’ll he happy to share the presentation here when I’m done with it.
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May be a good read
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Yep, I’m testing 
More data this weekend!
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Here is my slide show from the presentation at Medtronic this past Saturday.
For the event, I made three different sample bumpers; one of the “normal” materials, but with an innovative fabric attachment method that is newly legal and with 3X pool noodles to consider the “taller” bumpers that are now allowed. One is scrap material, including a stack of recycled Vex floor tile cutoffs and some 1/2" OSB backing. And one is my take on a maximally protective bumper.
Here are photos of the recycled materials sample.
One of the things these new rules are intended for is making it easier for low-resource teams to pass inspection and get on the field without penalty, so long as their bumpers won’t cause harm to the field or other robots. I applaud this idea. The “foam” floor tile recommendation is likely to get more specific when the game rules are revealed. Carpet tiles, rubber tiles, etc. are going to be illegal and there are probably foam tiles that won’t meet the “squeeze test” which is what I expect inspectors to apply to make sure bumpers are okay to play. But these old Vex tiles should be fine.
Here is the “normal but taller” bumper.
Pretty self explanatory. Three noodles instead of two. the channels on the back side are an upholstery technique that allows you to stretch and tighten your fabric without pulling it unevenly or using very many staples; just make two channels wide and deep enough to include both the fabric and a wooden dowel rod. Tamp the rod over the fabric into the channel, and use a few staples to tack it down.
This is the wildest new option.
The layers are (bottom to top):
- 1/2" thick HDPE plastic backing
- 3/4" Flotex foam (softest)
- 1 1/2" EVA foam, 2#
- 3/4" Cross-linked PE foam, 3#
The idea is to put the softest material nearest to the robot frame, and the hardest closest to the fabric wrap. I’ve also wrapped this piece in two pieces of Schoeller Keprotec fabric (maroon and navy) and one piece of Schoeller Schussmeister (Natural, it needs to be dyed). All of these are durable options.
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Thank you so much for posting this!
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Looks promising!
What’s your plan for testing?
When and if I get around to it I think the most effective test will be to bolt each segment to a 150# box or flat block of material, then put a 150# weight on a swing, and let it drop into the bumper sample. I am not going to go through the systematic testing with force sensors and such; I don’t think Woodie did that kind of testing in the beginning, I think he intuited that pool noodles and plywood would protect robots from each other, and in the same spirit I think it’s unnecessary to put lots of resources toward this effort. I’m sure some of the high resource teams will put the effort in to do that, and the rest of us will benefit from their results in a year or two.
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I like your plan. Perhaps take slo-mo videos (from a phone camera) of the collision to see how the impact is distributed.
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Ideally without cover material on the ends (corners), so the padding deformation is visible, I should think.
thank you for the post
question about using the dowel for holding the fabric in place.
what holds the dowel in place and how do you do the corners?
do you have a design/assembly guide for that you are willing to share
- Neil 4512 Otter Chaos
I recently did a live presentation about this and I believe it was recorded, including the portion about how the dowel works. I will reach out to the person who was making the video and see if she is willing to make it public.