An example of our Reversible Bumper design. Switch from Red Alliance to Blue Alliance without removing the bumpers from your robot.
A word of caution: check the bumper rules very carefully, specifically R27. We’ve always used color-matched velcro to avoid issues with how that rule is interpreted.
Our team has used white or black velcro for the last 4 years. It will be fine. I feel comfortable arguing with an inspector for an hour about why the color of the velcro should not make a bit of difference. If they disagree, beg them to tell you how the color of your bumpers does not comply with the spirit of the rule.
That said, bumper rules are fairly simple for inspectors to grasp, especially the inspectors that are not heavily involved in FIRST for the rest of the year. The bumper police are ALWAYS ***wayyyyyyyy *** too strict about bumpers.
One thing to watch out for (for which we got repeatedly flagged last year, ugh) is if a flap becomes unvelcroed and even grazes the carpet and the ref sees it, you are penalized (or warned, and then penalized). Not sure if that applies this year since bumper zone goes from 0-7.5 inches, but you get the idea.
We made these last year and they were really great. If you have the velcro fold over behind the bumpers and attach there, then it’ll just be red or blue that is visible. We did that with black Velcro and had no inspection issues, but YMMV.
Um, no, that’s not the case. I can refute your always statement, and I can refute your “simple” statement, both from personal experience dealing with a missed item on the inspection list. (For some reason, people tend to get “frame perimeter” and “frame of the robot” confused–especially rookie inspectors.)
One thing to watch out for (for which we got repeatedly flagged last year, ugh) is if a flap becomes unvelcroed and even grazes the carpet and the ref sees it, you are penalized (or warned, and then penalized). Not sure if that applies this year since bumper zone goes from 0-7.5 inches, but you get the idea.
I don’t think you understand the rule(s) in question very well. Last year’s zone was from the floor to 7 inches. You probably didn’t get flagged for the flap being on the carpet. You probably DID get flagged for a volume or color violation–most likely a volume violation caused by the flap going outside the allowed volume. This sort of thing can be cleared up by a discussion with the Head Referee as soon as possible after the match (while they still have a chance at remembering why you got called for a foul).
This year’s rule is mostly the same, but you do have 16" of extension outside the Frame Perimeter allowed instead of having to stay inside your volume at all times.
You mean R27B, which happens to include an exception to the color rules for Velcro/snaps on the wood backing?
We learned quickly to have an elastic loop through the flap set so that if the velcro let go from vigorous robot interaction the elastic will pull all the flaps back in place. I think we’ve have reversible bumpers since 2012 and we’ve dealt with all sorts of hiccoughs related to them.
Yes.
Has anyone tried internal magnets instead of Velcro?
I’ve noticed more use of Rare Earth magnets in different wearables recently. I was thinking about switching to that, but didn’t have any data as to whether they would stay in place during rigorous game play.
Unfortunately I do not think the magnets will be able to stand up to the 2:30 of game play each match. (I could be and hope I am wrong) but from my experience with those magnets, they can not hold up to the rigors of robot to robot and field interaction.
This site is decent for strength calculations with the magnets though if you are contemplating:
https://www.kjmagnetics.com/products.asp?cat=1
Check your bumper rules and see if adding hard components to the bumper outside of the allowed plywood and metal brackets is legal.