Use of Lexan and ABS


#1

There is some question that has arisen based on the use of plastic on a robot. Can a single robot use both the Lexan and ABS plastic sheets as long as the total surface area of the plastic does not exceed 288 sq inches (12" x 24" = 288" sq) or could be cut from a single sheet of the material. If all of the pieces could be cut out of a single 12x24 sheet of Lexan, could you cut several of the pieces out of ABS and use the ABS parts instead of the Lexan. So a single bot would have both Lexan and ABS, but the total area would still be cutable from a single sheet of one or the other material.

R7 States -
Non-shattering plastic from the following list; polycarbonate (Lexan), acetel monopolymer
(Delrin), acetal copolymer (Acetron GP), POM (acetal), ABS, PEEK, PET, HDPE, LDPE, Nylon (all
grades), Polypropylene, FEP; as cut from a single 12" x 24" sheet up to 0.070" thick.
i. Shattering plastic, such as acrylic, is prohibited.
ii. Plastic may be mechanically altered by cutting, drilling, bending etc. It cannot be
chemically treated, melted or cast. Heating polycarbonate to aid in bending is
acceptable.

My interpretation of the rule is that the 12"X24" is simply a limit on the amount of plastic that may be used within a bot. Not a restriction to using only a single type of plastic. Please provide clarification of this for us.


#2

For me the word single implies one.

For a real answer you’re going to have to put this on the official q and a.


#3

You have to be able to tetris all of the parts together into a full sheet. This means holes drilled count against your total area, and you are not simply claiming that less than 12*24 in^2 of lexan is in use.


#4

Your interpretation of the rule seems to be correct, as stated by Karthik many times throughout the years. The rule is meant to be a limit of plastic from a two-dimensional perspective without regard for the type of plastic, so long as it’s VEX legal.

This means:

  1. You can use varying thicknesses of plastics as long as no pieces exceed a thickness of 0.07" and can fit within a 12"x24" rectangle.
  2. You can use varying types of plastic as long as no pieces exceed a thickness of 0.07" and can fit within a 12"x24" rectangle.

YesToThickness YesToThickness2 YesToThickness3

Hopefully, this finally clears things up!