Routing grooves in acrylic and polycarbonate

[jcrowe1950]

Hi Folks,

    I have a customer who needs to route grooves in plastic sheets for a job. He is having some issues WRT his CT VA plugging with plastic chips. Can anybody suggest a router bit and speed for both acrylic and polycarbonate groove routing. From my research it looks as if acrylic and polycarbonate require different bit speeds and feed rates to successfully accomplish the goals. Any information gratefully appreciated.

 

[Crazyraceguy]

He needs an O-flute bit. These are essentially a single flute that is very wide, wraps around in a slow spiral leaving it open to clear chips. They work well in plastics and aluminum, though there may be different specific geometries for each? Shouldn't be hard to find.
I use both 1/8" and 1/4" styles.

 

[Cheese]

Here's a Whiteside O-flute bit on the RH side.

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[Rick Herrick]

I have read that using 'cast' acrylic is much better than 'extruded'.

 

[jcrowe1950]

OK, you guys....

    Thank you so much for this information. If I ever make it to your neck of the woods, I will gladly buy you both a beer of your choice. Really, I appreciate the information very much....

 

[Packard]

I’ve tried my router on acrylic, and the blade speed is way too high. 

Some drill presses have bearings sufficiently robust for this type of work, but a milling machine is the equipment of choice.  Probably with a bit speed of 200 to 300 rpms. 

As a side note, I have cut plexiglass on the table saw using an all steel plywood blade.  It probably had 150 to 200 teeth.  The key was to mount the blade backwards.  I don’t recall where I saw this suggested.  I used that method for the vinyl soffit material and the cuts were super clean.

But I have never tried cutting dadoes in acrylic, so I cannot comment on that. 

I did flame polish the edges (you can find videos online how to do that).  It left the machined edges as smooth as a plate glass.  And it only takes seconds to do.  So a good technique to learn. 

 

[rst]

Plastic and aluminum saw blades have the same geometry, as far as routing I use the 3 setting on my Festool routers.  For other make routers, which I used before investing in Festool, you can slow the speed using a cheap 15 amp controller.  I use my controller also to slow my PC Sawboss for cutting in lite kits on commercial steel doors.