When this came up last year, here’s what I said:
I think that all continues to hold true.
Additionally, I would support the idea that bumpers be made optional again, as long as it’s clear that robots running without them would not draw more penalties against the opponent (despite being more likely to be damaged), and that they would have to identify themselves in an equivalent way (e.g. coloured, numbered placards in the bumper zone).
Mandatory bumpers do have one big advantage: they save teams that build the robot to the full 38 in × 28 in limits from huge trouble when the frame twists, or their tolerances are off. This can be obviated with a simple note in the rules: “Build your robot smaller than the maximum limits of size to account for manufacturing tolerances and distortion due to damage suffered during gameplay. As a rule of thumb, you should consider building the robot at least 1 in smaller than each limit.”
Things like supporting the entire backing of the bumper are not helpful. If a bumper breaks, who cares? It’s a bumper. Either fix it with some sort of gusset, or cut it and call it two bumpers. The rules should be written to permit a simple, effective resolution to a broken bumper, instead of imposing a basically-worthless constraint on everyone—which, due to the phrasing, affects teams even if there’s no reasonable chance that their bumpers will break. During inspections at three events, I saw two teams with essentially unsupported bumpers along two sides (including one at the Championship…). They were forced to add structure to support the backing of their bumpers—even though, in all likelihood, the bumper backing itself was much stronger than the structure. By contrast, I saw more than a dozen teams that had small gaps behind their bumpers which were technically illegal, but which posed no real problem from an engineering perspective. And yet, the rule is clear: they must support the entire length of each bumper with the robot’s structure or frame. So mounting points were adjusted, or bumpers shimmed. This wasted a lot of time, both for teams and inspectors. But basically: this constraint is useless, and even counterproductive—either get rid of it, or write in a clause that specifically allows inspectors to override it based on their engineering judgment.
Bumper colours were very helpful for identifying alliances, but quite the opposite for identifying teams. With the location of the bumpers this year, and the fact that many robots were low, it meant that a lot of robots were hard to identify from a distance or on the webcast videos. While in the past, unique bumpers were easy ways to identify robots, this year, everyone had to rely more closely upon the team numbers (which are quite invisible in many webcasts). I’d be quite happy to see the rules allow the bumpers to be any colour, except for an inset patch (at least 12 in long) corresponding to the alliance colour, and containing the team numbers in white.
Bumpers should be required to be removable in 20 s per bumper segment. No exceptions. This isn’t rocket science, but because the rules suggest threaded fasteners, teams tend to go with complicated arrangements that require the insertion of hand tools into tight spaces. Teams will rapidly discover the existence of various spring pins if forced to design bumpers to be removed quickly.
Finally, though it’s not technically part of the bumper rule, the frame perimeter rule was a significant annoyance. Hopefully there won’t be any reason to need this next year—but if it does come back, tighten the definition.