Best router bit for creating slots in 3/8" polycarbonate sheets

[Don Morris]

I need to cut several slots approximately 6" long in some plastic I have that is about 1' square. The plastic is 3/8" thick polycarbonate (Lexan?). I've cut it before on my TS and drilled holes in it, but never successfully made nice slots because I always suspected I was using the wrong kind of router bit. There must be a "best bit" for this. Your advice please. Thanks!

[pat warner]

3/8 solid carbide (http://www.patwarner.com/images/404_b.jpg), whether straight or twisted, no problem.

[Rick Lizek]

You need to start reading the tooling catalogs of Amana, Freud, Onsrud and others. They will answer many questions and give ideas of things you never imagined. I never ask questions on forums. I just go to the answer.

[Myk Rian]

Up-cut spiral. Whether you're doing the cut in a table, or hand held.
The thing to watch for is heat. A heated bit will mess everything up. Very light passes, especially the first one for a clean edge.

[Tom Walz]

If you have trouble finding a tool that works you can call one of our Cutomer Service Reps. They are bright and know quite a lot. One of the things they really know is how to contact the engineers at Vortex, Whiteside and others. Carbide Processors 800 346-8274 or csq@carbideprocessors.com

The suggestions given above are very good. However we often run into people who actually have something unusual with what sounds, at first, like a common situation.

Tom

[Mark Burnette]

Definitely up-cut spiral. Polycarbonate is fairly soft with a low melting temperature. If you don't get the waste up out of the groove it will liquefy and try to re-attach inside the slot. Makes for a dull messy slot and a very hard-to-clean bit.

If you want a pretty groove try "flame polishing" it. Fan a propane torch flame over the cut until it turns clear. Practice on scrap first til you get a feel for what you can get away with before it blisters.

[Richard Coers]

Onsrud single o flute. Cuts like butter. Either spiral or straight.
http://www.onsrud.com/files/pdf/O_Flute_Plastics_Brochure.pdf