Stair-Step Bumper Design - Legality of Tetris-style bumpers

[AccurateFilms]

If my team (3161 Tronic Titans) decides to build a bumper set of 4 Tetris-shaped panels, does this violate the 2010 FRC Robot Regulations? The bumpers would basically be identical to the standard 'overlap' design, but would be offset by 2.5" so that the front of one panel is overtop of the next panel. Here is an illustration in two layers. Imagine one of the images being one plane of pool noodles, and the other image is the second plane. The colours indicate which pool noodles are connected. A side view is also included.

[Alan Anderson]

As long as only "soft" components (pool noodle and fabric covering) are used in the half-height extension into the corners, I believe that design satisfies the requirement to protect the corners. But I'm not sure the 5" bumper height rule can be interpreted to permit it.

I'm curious why you'd want to do it that way, though. It seems an unnecessarily complicated shape, and it strikes me as likely to have problems with the narrow bits of bumper getting bent and going outside the bumper zone in normal gameplay.

[AccurateFilms]

The soft parts are definitely the only ones past the corner, but we have determined that this way the impact is distributed along both axes instead of just one. Since the bumper is specified as two pool noodles, with only soft parts past the corner, is this not qualified to be part of the bumper? The backing must be 5", however the soft parts are two 2.5" pool noodles. In our design, both pool noodles are 2.5" and backed by 5x3/4" plywood. However, the corners even allow for a single vertical pool noodle, so why would two 2.5" noodles not be qualified? Could you specify which rule disqualifies this bumper setup?
Also, if we were to have an overlap design (say, the side panels are longer than the ends by 2.5" in each direction), wouldn't it suffer more from bending outward from the bumper zone? In our design, an impact that would normally be exerted on a side panel is partially distributed to the front panel. Here is an illustration.

[EricH]

It's not the sticking out we're concerned about, it's the fact that the side view shows only one on top and one on bottom in the corner zone.

I can specify a rule that could possibly disallow it: <R07-C>, which specifies a pair of stacked pool noodles. Granted, you meet the spirit. However, if you get a particularly nit-picky lead inspector, you won't meet the letter.

However: If you pay attention, you'll notice that beveling the corners is permitted. This may have the same effect.

You can also ask Q&A. If we say it's legal, and your inspector says it isn't, you'll have to redo your bumpers at the event. If Q&A says it's legal, and your inspector says it isn't, you can show him the Q&A.

I believe that another configuration you might ask about would be simply continuing the pool noodle around the corner, without backing in the corner area. This is shown in Fig. 8-2, but the figures are only for illustrative purposes. I remember seeing it legal, but I can't remember where or when (might have been last year). Ask about that.

[Alan Anderson]

<R07L> might be giving a list of the permitted ways to have bumper segments meet, of which the stairstep design is not one. Or it might be giving examples of ways to do it, and not restricting other designs. I won't guess as to which interpretation the GDC intended.

Originally Posted by AccurateFilms

Also, if we were to have an overlap design (say, the side panels are longer than the ends by 2.5" in each direction), wouldn't it suffer more from bending outward from the bumper zone?

What does "bending outward from the bumper zone" mean? I was referring to possibly bending up and/or down. The BUMPER ZONE is defined by a vertical measurement from the floor of the field.

[SteveJanesch]

The overlapped bumpers could be bent beyond allowable dimensions up, down, or out, so even if it's legal at inspection it could incur a penalty during match play. If your intent is to distribute impact along two sides of the chassis, some corner bracing connecting two bumper segments above/below the frame should accomplish this. Also, could you build four L-shaped bumper modules to cover half a side, around a corner, and halfway down the next side with some bracing around the corner? Last year we had two U-shaped bumper modules, one for the left and one for the right.