<R18>

A limited amount of custom plastic is allowed. Robots may use custom-made parts cut from certain types of non-shattering plastic. It must be possible to have cut all of the plastic parts on the Robot from a single 12” x 24” sheet, up to 0.070” thick.
  • The intent of the area/thickness constraints is to limit the number of custom plastic parts used in Robot construction, not to define an absolute volume. For example, using a sheet which is 0.035” thick does not permit two 12” x 24” sheets’ worth of parts.
  • Plastic parts do not have to be literally cut from the same original 12” x 24” sheet. However, all individual parts must be able to “nest” or rearrange into a 12” x 24” area. A collection of parts which theoretically have a total surface area of 288 in2, but cannot be nested onto a single 12” x 24” sheet, would not be legal. See Figure 36.
  • 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.
  • Legal plastic types include polycarbonate (Lexan), acetal monopolymer (Delrin), acetal copolymer (Acetron GP), POM (acetal), ABS, PEEK, PET, HDPE, LDPE, Nylon (all grades), Polypropylene, and FEP.
  • Shattering plastic, such as PMMA (also called Plexiglass, Acrylic, or Perspex), is prohibited.
  • Plastic sheets sold by VEX are considered “plastic” in the context of this rule, and are subject to the same limitations as “off-the-shelf” plastic sheets. Examples include the 276-8340 PET sheets, and the 217-6626 / 217-6627 polycarbonate sheets.
  • This rule does not apply to 3D printed plastic parts. 3D printed parts are not permitted in the VEX Robotics Competition, except as non-functional decorations (per <R8>) or as custom License Plates (per <R9>).
    • Note: The phrase “as cut from a single 12” x 24” sheet” is intended to mean that all individual plastic pieces must be able to theoretically “nest” or rearrange into a 12” x 24” area. The plastic pieces do not have to be cut from the same original 12” x 24” sheet. Teams are encouraged to “map” plastic use on a 12”x24” sheet of paper for reference at tournament inspection.


    Figure 36: Custom plastic parts must fit within a single 12” x 24” sheet of plastic.