# Perimeter

Hello, I am confused with the purpose of measuring the perimeter of the robot, this statement is found on bottom of page 63

Once you have installed everything but your bumpers, wrap a piece of string around your robot at the level of your bumpers, and pull it tight. Just like in geometry class, the length of string is the frame perimeter of your robot. Note that minor protrusions such as bolt heads and other fasteners are allowed to extend past this perimeter, but no more than 1/4 inch.

R23. BUMPERS must be located entirely within the BUMPER ZONE, which is the volume contained
between the floor and a virtual horizontal plane 7 in. (~17 cm) above the floor in reference to the
ROBOT standing normally on a flat floor. BUMPERS do not have to be parallel to the floor

So your Bumpers must be at or below 7" off the floor

Now this…

The ROBOT (excluding BUMPERS) must have a FRAME PERIMETER, contained within the BUMPER ZONE made up of fixed, non-articulated structural elements of the ROBOT

Then pull string around it This is your FRAME PERIMETER.

To recap its the robot frame below 7" that defines your frame polygon.

The importance of this is …In the STARTING CONFIGURATION which is how your robot starts each match : no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER, with the exception of its BUMPERS

So lets say you have a gear mechanism at 13 inches and during Tele-op you want to reach to 37" well that mechanism must START within your frame perimeter which when measured at the BUMPER ZONE and you extention is 5" longer than your frame. …so you would need and articulating mechanism to reach to 37" during Tele as at START it would stick way beyond your FRAME PERIMITER.

I’ll try to clarify a little bit.

There are two measurements affecting your robot:
–Volume: The volume your robot needs to fit in during the match.
–Frame Perimeter (which is NOT robot frame, but is determined by it): This restricts your starting volume, and is where your bumpers attach. In the past, it’s also been your robot’s size restriction, but not this year.

Now, the real purpose of Frame Perimeter: Take a string and wrap it around your frame in the bumper zone, stretching tightly. (You may want to use long surgical tubing, or a bungee cord, instead of string.) Anywhere the string changes direction is a corner of the Frame Perimeter, and needs to have bumpers on both sides for 6" from that corner, that are constructed and supported per the bumper rules. (And, in perimeter-measuring years, if it was longer than a certain length, you’d be figuring out how to shorten it. Don’t worry about that this year.)