2012 Bumper rule gray area

after looking at the bumper rules, Bumper height seems to be not mentioned anywhere…

either I am missing something, they missed something, or they intentionally left it ambiguous (perhaps to allow robots to cross the center bump and why lift kits appeared in first choice).

Bumper Zone is defined in the Blue Box under [R01], 2 to 10 inches from the floor.

ah. Brain fart.

No, not a brain fart. Perhaps the lack of a search, but nothing more.

But - does anyone remember Blue Boxes specifically mentioned as not being part of the rules in previous years? I can’t find any such definition this year.

look for corrections in future team updates.

so is that 2 to 10 inches measured from the bottom of the bumper correct???

No, from the floor, as mentioned in [R01] “… within the Bumper Zone, which is between 2 and 10 in. from the floor.”

The bumpers need to be totally contained inside of that zone, meaning the bottom can not be any lower than 2 inches from the floor, or the top any higher than 10 inches from the floor.

With the bumpers that low, driving over the center bump (not using ramps) is going to take a bit more thinking…

[R01] states, “The robot must have a Frame Perimeter that is comprised of fixed, non-articulated structural elements of the robot. The frame perimeter of a robot is defined by the outer-most set of external verticies on the robot that are within the bumper zone which is between 2 and 10 in. from the floor.”

To me this reads like it is only covering the side perimeter of the robot and not the bottom as I am trying to see if we can incorporate an extra set of wheels on a swing arm under the robot to allow us to lift our (2" from the floor) bumpers over that metal curb in the middle of the field.

Any thoughts on that?

Notice, if you place the bumpers in the higher part of the zone, the bottom of the bumpers would be about 4.5 inches off the floor. The barrier is only 4 inches tall.

It definitely seemed like the rules were missing the whole “definitions” section that they’ve had in the past, where things like frame perimeter and bumper zone were defined.

How the bumper zone is calculated with a swing arm changing the height from the floor sounds like a question to submit to the GDC.

Yep, I spent a good half hour searching for it Saturday afternoon. The unobvious definitions seem to be scattered throughout the blue boxes.

Wouldn’t it be closer to 5", slightly less for bumper covering material?

Another thing with the bumpers, is that one of the images seems to be incorrect, figure 4-2


Although there is some unnecessary bumper, I don’t see an issue with the circled edge.

A frame perimeter is contained inside a convex polygon.

We decided a better caption for that arrow would have been “not required”. Have to see if they change it.

The Bumper must be against the Frame Perimeter. On that particular corner, there’s a bunch of bumper material inside the perimeter.

If you want to make a separate piece of bumper-ish assembly along that inside edge, and count its weight as part of the Robot, then I don’t think there are any rules against it, but you can’t make it part of the Bumper.


Over the past few years, a number of teams have asked questions about configurations exactly like the one shown. The response has been, almost universally, “No, it’s not part of the bumper. No, that’s not the frame perimeter.”

Could you do it? Yep. Does it get counted as a bumper? Nope. Does it therefore count against size and weight? Yep. At least, that’s my interpretation. (And no, I’m not on the GDC or remotely affiliated with them. So this is not an official interpretation.)

Notice that a portion of the “interior bumper-like structure” extends beyond the Frame Perimeter - that’s the primary reason it’s not OK. The section of the actual Bumper that extends partially across the cutout is also troublesome; I don’t know if the rules address it as “unsupported” or not.

And as noted above, any bumper-like structures that do not qualify as Bumpers must be counted in size and weight.