Bumpers *other* than pool noodles?

I’ve been browsing the internet to try and avoid the CD summer lull and came across this gif.

If someone was to make bumpers out of insulation / spray foam, aside from legality, would they work? Would they crush and not fix themselves after impact? I’ve been tempted to find out myself, but I don’t know if anyone else has already ventured down the road already.

I had 8 inches of that polyurethane spray foam installed in our attic. Very effective insulation and vapour barrier, but very not cheap.

Also it’s definitely not what you want in a bumper (that has to take more than one hit). It’s pretty rigid, and it does crush.

I wouldn’t expect this stuff to take impacts very well since that’s not what it’s designed for. However it is pretty soft (at least, the open cell kind we have in our attic) and could probably go back to its original state a couple of times. The other thing is that you would definitely need fabric coverings (like we have now) since pieces might fall off. If you used a lightweight open cell foam which is mostly CO2, you might be able to get decent impact resistance. It would be an interesting experiment though.

If nothing else, your robot would be nice and toasty :yikes:

My thoughts are you could do it, but maybe not with the spray foam in the gif. A range of foam properties is possible, as you can see in this video, for example. The last spray foam products I’ve used would be too rigid for bumpers. I think house insulation would be similar but can’t say for sure.

To function properly for FRC, the foam would have to be quite resilient (return to original shape in short order, even if it doesn’t return full energy), and moderately stiff (probably closed cell so that the air pressure is a cushion). Building insulation foam is usually relatively brittle (does not return to original shape when deformed), though most of it is closed cell, and probably is too stiff on light impacts. A spray foam designed to fill boxes for shipment would probably be more appropriate. You would also need a rather contrived bounding material to get expanding foam into a shape to support the variation in the bumper height allowed in recent years through definition of a 7" bumper zone to contain a nominally 5" tall bumper.

Heh. Like pool noodles, er, pool bumpers?

Getting teams to make proper bumpers even now is hard enough, and that just involves cutting the pool noodles to the correct length. I wouldn’t even want to think about the difficulty we would have with getting teams to build bumpers to the right dimensions with spray foam, nor the absolute mess that would ensue for every team trying to use it.

Australian pool noodles disagree


Way back in 2006 before bumpers were well defined (and counted against your 120lb weight limit) we used strips of old flat-belt tank tread as bumpers. Hard to tell how something like that would hold up today considering how much more durable chassis were back then, but it certainly did the job of preventing damage to our robot at the time. :rolleyes: