Bumper Figure 4.4

[aldaeron]

R24 B Says

hard BUMPER parts (e.g. plywood, fasteners, etc) may not extend more than 1 in. beyond the end of the FRAME PERIMETER (see Figure 4.3 and Figure 4.4)

It does not specify which direction beyond the FRAME PERIMETER. Does that mean the attached image is legal (i.e. attaching a mount on the bumpers that picks up the chassis members on the inside of the FRAME PERIMETER)?

Thanks!

-matto-

[androb4]

I would say it's legal because we've used this method for a while now.

[GaryVoshol]

I concur that you should be OK. "Beyond" means outside the bounds.

This is truly a unique choice of words:

hard BUMPER parts (e.g. plywood, fasteners, etc) may not extend more than 1 in. beyond the end of the FRAME PERIMETER

The FRAME PERIMETER, being defined as a polygon, has no end:

FRAME PERIMETER: the polygon defined by the outer-most set of exterior vertices on the ROBOT (without the BUMPERS attached) that are within the BUMPER ZONE. To determine the FRAME PERIMETER, wrap a piece of string around the ROBOT at the level of the BUMPER ZONE - the string describes this polygon.

If you look at the pictures, what they are trying to convey is that hard parts can't extend more than one inch beyond the end of the corners of the FRAME PERIMETER.

There are two corners they mark OK, with ones with the butt joint and the mitered joint. Actually the outside point of the plywood would be 1.06" from the nearest point of the FRAME PERIMETER, so that fails if they left out the word "end" in R24B.

[MARS_James]

FRAME PERIMETER: the polygon defined by the outer-most set of exterior vertices on the ROBOT (without the BUMPERS attached) that are within the BUMPER ZONE. To determine the FRAME PERIMETER, wrap a piece of string around the ROBOT at the level of the BUMPER ZONE - the string describes this polygon.

We got flagged on this rule last year by another teams mentor who was a robot inspector who saw our robot early.

We had attachments that were above the bumper zone by more than an inch thus by being beyond the frame perimeter vertically since it is defined in the bumper zone of 2-10 inches

[aldaeron]

Thanks all. I think it was just late and I was getting worried and started reading into the rules things that aren't there. Just wanted to confirm with some others.

-matto-

[DELurker]

Quote edited...

Originally Posted by aldaeron

R24 B ... does not specify which direction beyond the FRAME PERIMETER. Does that mean the attached image is legal (i.e. attaching a mount on the bumpers that picks up the chassis members on the inside of the FRAME PERIMETER)?

The frame perimeter is a vertically-oriented (ie - perpendicular to a level floor supporting your robot in a natural resting state) infinitely long surface wrapped around the outside of your robot's frame, connecting all of the exterior vertices of the frame in order to form the smallest convex polygon possible (round robots have infinite vertices). There are only two directions of consequence: inside and outside. The GDC would hardly care what you do inside the frame perimeter. Therefore, the rule must be referring to the direction of "outside" the frame perimeter.

I think the key word here is "beyond" ...