One coiler wrote of using soft black plastic to build a rotary
switching system. I can't
stress enough the dangers of using soft plastics to build the rotary
disc. At one time, Lexan, poly carbonate was thought to be bullet
proof and thus was used by many coilers for the rotary disk.
I have done extensive research in this and found that Lexan or any
other poly carbonate is the
absolute wrong thing to use. It is not bullet proof and will also get
soft and distort with heat.
I did the bullet test and all it did was dent where the bullet hit
but the shock wave shattered the lexan like window glass. This was
after I had a beautiful Lexan rotary gap explode in my lab and I came
very close to being killed. Read a lot, get informed, use a lot of
caution. Good luck.