Bumper zone height

[Vermeulen]

R33 says:

Bumpers must be supported by the structure/frame of the Robot (i.e. the gap between the backing material and the frame must not be greater than ¼ in. and no section of Bumper greater than 8 in. may be unsupported). See Figure 4‑7.

I would interpret this as saying that for a bumper to be supported, the gap between the bumpers and the frame must be 1/4 in. or less. The right picture would then be OK because the bumper is supported over that length.

[Kevin Sevcik]

See here:
http://www.chiefdelphi.com/forums/sh...threadid=99458

Summary for your question: if the backing is within 1/4", the bumper is supported.

[protoserge]

[Edit: Internet is too fast]


As for the image, it's a non-scaled drawing so the notated dimensions are overruling to any perceived scale.

[slijin]

Originally Posted by Duke461

Did FIRST make a mistake/typo in this picture? The two gaps labeled 10 inches are clearly not of identical lengths ( i even measured to make sure ). I understand why the "not ok" on the left is not ok, but, given the current numbers, i do not understand why the "ok" on the right is ok.

Originally Posted by Vermeulen

I would interpret this as saying that for a bumper to be supported, the gap between the bumpers and the frame must be 1/4 in. or less. The right picture would then be OK because the bumper is supported over that length.

Not really - that interpretation makes the 7"x7" intrusion illegal.

Although not phrased particularly well, what [R33] is really saying is that any intrusion into your bot cannot exceed both 1/4" of depth and 8" of width. In other words, it's an either/or thing - if you're exceeding 1/4" of depth, you can't exceed 8" of width and vice versa.

[Duke461]

Originally Posted by slijin

Not really - that interpretation makes the 7"x7" intrusion illegal.

Although not phrased particularly well, what [R33] is really saying is that any intrusion into your bot cannot exceed both 1/4" of depth and 8" of width. In other words, it's an either/or thing - if you're exceeding 1/4" of depth, you can't exceed 8" of width and vice versa.

Ok it all makes sense now

[Al Skierkiewicz]

Samuel is correct. If there is a gap behind your bumper structure due to bolt heads, welds, warped plywood, etc. that do not exceed 1/4" then the gap is legal. If you have an irregularity in your frame for any reason, that exceeds 1/4", the width of said gap may not exceed 8 inches. Any gap greater than 1/4" is interpreted as "unsupported".

R33 Bumpers must be supported by the structure/frame of the Robot (i.e. the gap between the backing material and the frame must not be greater than ¼ in. and no section of Bumper greater than 8 in. may be unsupported). See
Figure 4-7.

Please note that this allows certain drive train designs to have gaps in the frame for wheels while still providing support for bumpers that meets the above rule.
This rule is identical to last year.

[GaryVoshol]

Originally Posted by mdiradoorian

so bumper zone is within 2 to 10 in off the ground then and around exterior corners.

The Bumper Zone is a zone between 2 horizontal planes and extending outward forever. These 2 planes are 2 inches and 10 inches from the ground.

[Ninja_Bait]

The intent of R33 is to prevent bumpers from cracking under a hard impact. With the support restrictions, theoretically, the risk of your bumpers doing so is lessened. (Learned this in Hartford from an inspector.) Keep that in mind as you design bumpers.

[Kusha]

Off topic: Could you have a bumper start at the 10inch mark. IE the bumpers lowest point is at the 10" mark?

[Ninja_Bait]

Originally Posted by Kusha

Off topic: Could you have a bumper start at the 10inch mark. IE the bumpers lowest point is at the 10" mark?

No. The ENTIRETY of the bumpers must be in the bumper zone.

[SenorZ]

I can see an issue when a high-bumper robot is going over the Barrier and a low-bumper robot approaches from the other side. There could be some serious overlapping issues and possible [G27] violation.