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I need to make a number of new plexiglas templates for some classes I teach. I have intermittent success routing plexi, and am interested in hearing other ideas. I typically rout 1/4" or 3/8" cast plexi on the router table with various results, some not so pretty. I have been reading about various techniques on the web such as using WD-40 or cutting fluid as a lubricant, using the largest size bit possible, using the slowest speed possible, using only spiral bits, using slowest feed rate, using fastest speed rate, etc. All I need is to find a system that works good. Got one? Thanks, Bob

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It's very dangerous routing plexi (acrylic). It can shatter sending shards of shrapnel flying around your shop.
You are much better off with lexan (poly carbonate) for safety as well as the fact that it routes beautifully.

They make various special router bits for plastic that often has a single cutting edge with a 90° rake. This can prevents grabbing and melting/burning

O.K., I understand about routing cast plexi. Been there, done that many times and know about shattering. No experience with routing Lexan. I just called and ordered some. So what is the recommended technique, bits, etc. for Lexan? Thanks, Bob

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

I've found that no special steps need to be taken on Lexan. If you have a variable speed router, you might slow down the bit a little just to prevent heat buildup. But the stuff is really a dream to machine.

+1 on the Lexan. It is worth the extra money.

Have a look at these 0 flute plastic cutting bits:

http://www.toolstoday.com/c-432-plastic ... -bits.aspx
http://www.toolstoday.com/p-5882-solid- ... -bits.aspx

slower feed and use a coolant. In my machining days we would use a 2 flute cutter and a solution of about 1 tea spoon of dawn to a qt of water. It helped to keep the cutter cool and avoid plastic buildup on the bit. Also held the ships at bay. Doesn't take much a few drops leading the cutter will do the trick.

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John Hall
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