Robot dimension

To get an extra couple inches of length on our bot, the corners are chamfered. Do inspectors measure the actual perimeter (length of each side) or just the length and the width?

Please post a sketch with dimensions. Are they chamfered significantly? To the point where your bumpers also follow the chamfer? If so, then probably.

Frame perimeter is normally measured with a fabric tape measure to measure the actual perimeter.

The frame perimeter is measured with a string around the FRAME PERIMETER as specified in the blue box under R1. If I understand the question correctly, it’s the actual convex perimeter (in the bumper zone) that matters, not the minimum bounding rectangle. Note that whatever FRAME PERIMETER is defined, all of the robot except bumpers and “minor protrusions” must start within it per R1, and the bumpers must conform to it due to a number of bumper rules (R24 through R33).


All 4 corners are like these 2, and our bumpers will be conforming to them.

Make sure you understand R33, specifically the portion about the last 1/2" of each bumper wood segment being backed (<1/4" gap) by the frame perimeter. I am not if you are planning to add anything to your frame perimeter or not but if you aren’t it would be unlikely to pass R33.

Please evaluate rule R33 and make sure your robot conforms to the bumper coverage so you do not have to redesign bumpers at your first competition.

The bumpers will be covering all 8 sides. The front, rear, and chamfers will have be supported across the whole lengths of each of those. The sides will be supported every 7 in. As I read it, as long as the chamfers will be in full contact with the bumpers, we are fine.

Not quite. Put a tab along from the corner across the wheel, 1/2" or more. Then you’ll be within the rules. That’s the “end of a segment” @AllenGregoryIV was talking about. Silly. I know. But that’s the way the rule is written.

Ah ok, I understand now. Thanks everyone for your help. I should have just kept things easy and made it a rectangle but we don’t do “easy” on my team so that’s that :smile:

If you measure your perimeter as Allen describes, what do you get? It is unwise to design/build so that you get 120" =- 0.5" since any small error on your part and you are over the 120" maximum limit. You may end up failing inspection and have to do some really nasty surgery on your chassis.

Unfortunately, I saw many teams last year that viewed the robot sizing rules as a target rather than a maximum limit.

All of our chassis rails will be machined so we aren’t really worried about accidentally going over. Currently it’s at about 118.25

Please review all of the bumper rules…i.e. R24 and Fig 10-2.
A robot’s Starting Configuration volume will be determined by inspectors as specified in R3 and R4.