So far I Cannot find anything in the Game Manual stating that the use of Functional Plastic Parts (NOT 3D printed) is illegal. Does this mean that using Plastic for Functional Parts (Such as a Gear) is Legal?
The game manual does not restrict what parts you can make from your plastics allowance given in rule R25; therefore it looks like you could make, for example, up to 12 four-inch diameter gears (but they’d be pretty thin, and probably not work well).
if you check 2654e’s reveal video they do have a plastic sprocket. I would say that the main reason to use plastic gears or sprockets is to get a certain amount of teeth that regular gears/sprokets do not provide.
On a related note, are we allowed to glue the plastic together so it is thicker, but we used two sheets?
Please check out the game manual (and maybe use the search bar) before you type these three words into the forum. This page has a link to the current game manual: Competition - V5 - VEX Robotics
For your question, please take a look at rule R27 (e)