Robot Bumpers Rules

[idoshamir]

Hello,

Can someone confirm for sure that the attached picture is a legal build?
Bumper-wise - do we have to go the full 8 inch in?
Frame-wise - is this legal?



( http://imgur.com/ToEyS1k )

Thank you!

[excel2474]

My understanding of the rules is that your configuration is legal.

[Kevin Leonard]

As long as you have 8 inches of bumper extending from each of those questionable corners, you should be fine. Really read the bumper rules carefully about how you have to support the bumper as well.

[MechEng83]

My understanding is that that configuration is not legal.

Bumpers must extend 8" from the corners of the FRAME PERIMETER. The FRAME PERIMETER is not defined as the actual perimeter of the frame, but the polygon defined by the external corners of the robot frame. The only exception is if one of the FRAME PERIMETER sides is less than 8". In your example, it appears there are 4 sides to your frame perimeter, so the extent from the corner that has a bumper should still be 8"

Disclaimer: I am not an inspector or the GDC.

[Jake177]

R19:
ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 8 in. of BUMPER must be placed on each side of each outside corner (see Figure 4-5). If a side is shorter than 8 in., the entire side must be protected by BUMPER (see Figure 4-6). For the purposes of R19, a round or circular FRAME PERIMETER has an infinite number of corners.

If you look at Figure 4-5 in the Manual, the lower-left picture expressly shows that this configuration would not meet the bumper requirements. The only time you are allowed to have less than 8" of supported bumper extending from a corner is when your Frame Perimeter has a side that is less than 8". (Such as in Figure 4-6.)

[FrankJ]

You must have a bumper 8" on each side of an exterior vertex.
each end of the bumper needs to be supported by 1/2" of frame.

So no you are not legal.

[idoshamir]

Thank you all. So the majority here agrees that if the bumpers extend into the "hole" 8 inches both sides we will be OK?

I am also trying to get a formal answer for FRC, but I need a quick decision...

[excel2474]

R19

ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 8 in. of BUMPER must be placed on each side of each outside corner (see Figure 4-5). If a side is shorter than 8 in., the entire side must be protected by BUMPER (see Figure 4-6). For the purposes of R19, a round or circular FRAME PERIMETER has an infinite number of corners.


Maybe I'm not understanding that correctly, but I think it would be legal.

[FrankJ]

The each end of the bumper will have to be supported by 1/2" of frame. If the bumper extends into a hole the end of it will have to be supported.

[Al Skierkiewicz]

Ido,
Your drawing is not a legal bumper. In inspection this would be explained to you. The 8" minimum rule applies to the highlighted part of your frame. The 8" is measured on the frame or bumper backing. See Fig 4-5, you robot is the lower left drawing.

[idoshamir]

I think we got it. Thank you all.

[Jake177]

The term "side" in R19 refers to a side of the FRAME PERIMETER. In the given case, the robot's FRAME PERIMETER has four sides, all of which are greater than 8". It doesn't matter that one of the sides happens to have a gap in it, it is still required to have at least 8" of bumper at each corner.

[Jon Stratis]

Originally Posted by excel2474

R19

ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 8 in. of BUMPER must be placed on each side of each outside corner (see Figure 4-5). If a side is shorter than 8 in., the entire side must be protected by BUMPER (see Figure 4-6). For the purposes of R19, a round or circular FRAME PERIMETER has an infinite number of corners.


Maybe I'm not understanding that correctly, but I think it would be legal.

No, you aren't understanding it correctly. The "side" that is being referred to is a side of the FRAME PERIMETER - it would be the entire side of the robot, including the gap in the actual frame. Wrap a string around the robot and pull it tight - that's the FRAME PERIMETER, and it spans openings like in the drawing. The two short bumpers in the drawing are both on the same side, and thus both have to be 8" or greater in length.