Quote:
Originally Posted by Kevin Sevcik
I submit the following two photos into the evidence:
http://www.chiefdelphi.com/media/photos/31159
http://www.chiefdelphi.com/media/photos/23644
A 38" span of bumper isn't likely to survive many of those.
As you say, high quality marine hardwood bumpers with reasonable length spans would be more than fine, and we both know that. But the bumper specifications don't call for high quality plywood, nor maximum span lengths. Instead, they call for the bumpers to be fully supported along their length, which serves a similar function of protecting rookies from underestimating impacts and ending up with snapped bumpers. The rule is, after all, ultimately there to protect less experienced teams from themselves. As are a large number of the rules. Which is why I don't spend time railing against having to electrically isolate everything from the robot frame, the various fusing rules, and other things that I know enough about to do differently and better. |
If you compare the failure modes of those electrical rules (burning wires, short circuits, etc.) to the costs of imposing them (it's easy to spot an out-of-place breaker, or test for a grounded chassis), it's a pretty reasonable proposition to mandate those things.
On the other hand, even assuming a violent collision, what's the failure mode of a snapped bumper—plywood hanging limply from cloth? That's hardly in the same league as an electrical fire. (And the bumper repair might even be straightfoward: cut the ends smooth to make two bumpers, and re-brace it somehow.)
So, while you could attempt to define what's a strong frame and what's sufficient structure, and then assess every robot by those standards, I don't think you're going to get much value for the effort (because most bumpers don't break, and the ones that do are probably not a big deal). I also think that you run the risk of inconsistent officiation ("strong enough" is probably a subjective measure) and dispute (because teams will probably believe that their solution is sufficient).
But if a guideline (rather than a rule) captures the intent to caution teams against weak bumpers, why not just opt for that? What's the point of trying to define a frame, and then having to enforce that ruling? And what's the harm in putting the (rather light) burden of building a robust bumper squarely on the teams? I hope that when this gets asked to the Q&A, that they take the opportunity to issue that caution, and just let teams pay harmless lip service to the rule (at their own peril).
After all, although I'm a fan of specificity in rule-making, I don't think that there's a significant benefit for FIRST to interpret this in anything but the most permissive manner.