Yet another bumper thread

[Tristan Lall]

Originally Posted by EricH

This year, the GDC has allowed pockets for bolts, etc.
http://forums.usfirst.org/showthread.php?t=11389

I hate to be the bearer of bad news, but if a team is trying to make their bumpers clear a protrusion on the robot, then by definition, that protrusion forms part of the perimeter. Bumpers have to follow the contours of the perimeter.

I fully support the idea of FIRST issuing a clarification on this subject. It's just that I don't think this is a good interpretation of the rules. It's particularly bad, because although the answer is technically correct (there is no such direct prohibition), the rest of the bumper rule makes this technique at best useless, and in pretty much all cases, illegal (because of the perimeter requirement in combination with the minimum bumper coverage and length).

This could be salvaged, however, by loosening the requirements a little bit: just as they stated (in a Q&A, not an update) that a little gap between the bumper and its supporting structure was (sometimes) legal, they could clarify that bumpers don't always have to follow the perimeter, in cases of small protrusions. Put these two things in an update, and everybody's interests will be satisfied. (Of course, some suitable definition of a small protrusion is necessary here, to avoid neutering the perimeter clause completely.)

I also think that it's interesting to hear that the GDC no longer feels that this will introduce undue weakness into the bumper. (This was their rationale for the 2008 prohibition on this design feature.) Do they believe that requiring a structural element to span the entire bumper alleviates this concern? I never personally felt that this was a structural issue, except in extreme cases, and I would have preferred FIRST to either define a strict requirement in the rules, or conversely, give inspectors latitude to determine what is and is not strong enough. The former has the advantage of maintaining consistency, while the latter is at least forgiving to the teams and the officials.

Incidentally, the rulings last year depended on teams reading the one or two Q&As out of hundreds that dealt with this topic, and noting that for the particular case of the 2008 bumper rule, the Q&A was clarifying an existing requirement (teams must build to the bumper specification), and not making up a new restriction (which would be dubiously valid). That's a fine point, but under last year's rules, the teams were expected to follow it.