R401 says that “ROBOTS are required to use BUMPERS to protect the entire FRAME PERIMETER.” In this case, is the frame perimeter defined as a 2D outline (like the name would suggest) or does it include all the metal surfaces along the robot’s perimeter? I’m wondering if it would be legal to have bumpers that don’t cover the bottom half inch of the frame, to allow for a cutout of part of the frame in front that would make under the bumper intakes easier.
In other words, would the robot below (credit to @kingc95) be legal, even though part of its frame is exposed below the bumper?
R402 specifies the the horizontal positioning of the bumper (between floor and 7.5in)
R407 specifies dimension of the bumper implied by its construction (5in tall)
Those rules insure contacts between robots will always be between bumpers, and frames will never touch. I think having parts of frame uncovered by the bumpers is fine.
Frame perimeter has a definition in the glossary. The frame perimeter is defined as being in the bumper zone. Robot parts above the bumper zone are not frame perimeter. The bumper zone is 7.5 in high. The bumper is a nominal 5in. So the bumper cannot cover in entire bumper zone.
Should be legal as far as I’ve always understood the rules. The exposed metal under the bumper shouldn’t be contacted as the bumpers stick out 3.25 inches from the frame. Also long as everyone’s bumpers are in the 7.5 inch zone they will always contact bumper to bumper.
That placement is also exactly as high as it can legally be to get the most clearance while driving over a note. The top is at 7.5 inches on the dot.
If this frame was 2x1 bar stock rather than 4 inch tall wall plates you wouldn’t see anything. The KitBot plates are ~80% of the size of a bumper so if you start to shift the bumper up or down in the bumper zone some part is more likely to be exposed. Still legal though.
I’m hard pressed to find examples online of “high bumpers” on a robot in pictures because everyone takes photos of it running on the ground while standing so you can’t see the ground clearance well or if there’s parts of frame below.
We had about 3/8" of our 1x2 tube frame exposed at the bottom of the bumpers on last year’s robot, due to having a very low frame and purposely high bumpers (right at 7 1/2", to make sure the bumpers didn’t ground out as it climbed onto the Charging Station). It passed inspection with no problems. The real key is to make sure that the frame supports the bumpers:
R410 *BUMPERS must be supported. BUMPERS must be supported by the structure/frame of the ROBOT (see Figure 8-8). To be considered supported, a minimum of ½ in. (~13 mm) at each end of each BUMPER wood segment must be backed by the FRAME PERIMETER (≤¼ in. gap, ~6mm). “Ends” exclude hard BUMPER parts which extend past the FRAME PERIMETER permitted by R408-B.
Additionally, any gap between the backing material and the frame:
A. must not be greater than ¼ in. (~6 mm) deep or
B. not more than 8 in. (~20 cm) wide
So, as long as the frame is still backing and supporting the bumpers, it should be perfectly legal.
