Bumper Height?

I just looked over the rules again in search of this, but I was unable to find where they specify the required bumper height this year. This seems to be another major oversight by the GDC in regard to bumper rules. If anybody finds it in the manual, let me know where. Otherwise, I can post on the Q&A forum.

I assume they haven’t changed from last year, what was the range they were supposed to be within?

Although it’s not given in <R08>, they do specify the bumper zone as being between 1 in and 7 in from the playing surface (in a playing configuration).

That is a change from last year: it’s been dropped by an inch and a half.

It is specified in the definition of “Bumper Zone” at the beginning of Section 8 of the Competition Manual.

BUMPER ZONE – the volume contained between two virtual horizontal planes, one inch above the floor and seven inches above the floor.

This brings up an interesting question when taken in conjunction with the definition of “Bumpers”

BUMPERS – Bumper assemblies designed to attach to the exterior of the ROBOT within the BUMPER ZONE, and constructed as specified in Rule <R08>. BUMPERS are excluded from the weight and volume calculations specified in Rule <R11>.

Emphasis mine

So the bumpers must attach within the BUMPER ZONE but the bumpers themselves do not have to be in the BUMPER ZONE? This is obviously not the intent and is lawyering of the rules, but it is interesting to note.

Ah, thanks for the clarification.

And I’m sure you wouldn’t get away with 4 ft high bumpers, no matter where they were attached. :rolleyes:

<R08>
P. BUMPERS must be mounted to the ROBOT within the BUMPER ZONE, and must remain there. The BUMPERS must not be articulated or designed to move outside of the BUMPER ZONE.

what i was just thinking tho is that the bumper zone is 1 to 7 inches off the floor… and the bumpers are required to be at least 6 inches long… does this mean we could vertically mount bumpers, say on the front of our robot?

Nice thinking, but <R08> B reads: “BUMPERS must use a stacked pair of 2-1/2 inch “pool noodles” as the bumper material.”

If those pool noodles aren’t stacked, you are in violation.

well it’s not as tho the bumpers would be any different then normal bumpers… other than their orientation. the pool noodles would be stacked inside the bumper… it’s just the bumper is oriented so that the length of the bumper goes along the vertical… if we were to interpret stacked that way then we can’t have inclined bumpers either? so no inclined chasis? or can we have an inclined chasis but we have to compensate? or can we have them at an angle but not vertical? how about 89.9 degrees?..

All the bumper rules seem to point to having them horizontal. Stacked is stacked is stacked: If I put two blocks in a stack, then tip it over sideways, is it still a stack? No. Replace “blocks” with “pool noodles”.

If you really want to, Q&A it. I have a hunch that the GDC will say, “Are you out of your mind?” or something similar.

I like your creative thinking (really: it’s useful to consider all options), but I do believe that Eric is correct here. (Also, while the use of “stacked” might not be completely airtight, it would be hard to say that a design in which one noodle was almost entirely supported on the other noodle doesn’t qualify. Maybe there’s an edge case where that definition would be inadequate, but I think that when taken together with the other limits that govern bumper construction, it’s sufficient for this purpose.)

There are other issues with vertical bumper segments: tolerance and length. The bumper zone is between 1 in and 7 in, with no stated tolerance on each dimension (which is reasonable, since you only have 5 in tall bumpers, so there’s an implied margin for adjustment). But what’s the length of a vertical 5 in × 6 in bumper? Is the length 5 in, and the height 6 in? (That’s doubly illegal.) If not, how do you justify measuring the height in such an unconventional way (i.e. in a horizontal direction)? And even if you do justify it, how do you fit a bumper segment that is MIN 6 in into a space that is 6 in ± 0 in (from 1 in to 7 in from the ground)? Absent FIRST specifying some other tolerance on these dimensions, you’d logically have to demonstrate that the bumper was exactly the right height. (This is impossible, for all intents and purposes.)

The bumpers have to be made from a 5" tall piece of plywood (and associated other parts…) So you basically have a zone of from 1-2" off the floor that the bumpers have to be mounted in.

The 6" inch requirement is for the minimum horizontal length. This would mean that the minimum size for a plywood backer is 5" tall and 6" long.

So the minimum coverage for a robot is:

Corners with plywood pieces 6" long completely supported by the robot.
For standard rectangular/square robots this would lead to 48" of coverage so a full sized (28 X 38) robot would need 40" more of bumper somewhere.

For a Pentagon shaped robot that would be 5 corners so 60" of corner coverage and they would need approximately 28" of extra bumper somewhere.

For a Hexagon shaped robot that would be 6 corners so 72" of corner coverage so an additional 16" of coverage

etc…

I believe this to be unambiguous in both the rules/updates and in the Q and A.

The only real issue might be if you design curved and not linear faces on your robot… and then you would have to make sure that in any configuration you would strike a wall with the bumper…and the bumper piece you strike the wall with is at least 6" in length.

I am somewhat mystified why everyone is still discussing this as it seems that the GDC made everything abundantly clear in the update and in the QA answers.