Routing Lexan

[Bob Gleason]

Now that I'm involved in making some lap steels that require templates for routing cavities in solid wood, I'm wanting some clear Lexan templates for inside cuts, rather than the material I usually use so that I can see what I'm doing more easily. Normally, I'm just cutting Lexan on an outside line on the bandsaw and sanding to the line. Can't do that with inside cuts. No problem making the MDF template pattern for routing the Lexan, but I've had a couple of instances of the router wanting to melt and grab the polycarbonate when I try to pattern rout it. Just wondering about any learned advice on router bits, speeds, tips, etc. Thanks, Bob

[tippie53]

I use a 2 flute cutter and use water as a coolant with a touch of dawn soap If you have a variable speed turn it way down. Watch the chips they should look curled like a small sea shell. You want to cut as fast as you can get the heat in the chip.

[rcnewcomb]

A single flute bit such as the Onsrud Solid Carbide One Flute Downcut O Flute should work well. ->Link

As John said, keep the RPMS as low as possible, and also try to move the router quickly through the material.

[Bob Gleason]

John, Do you lubricate from just a spray bottle or what?--Bob

[Bob Gleason]

How about the diameter of the bit?

[tippie53]

I use a spray bottle a down cut bit will push chip into the work adding to the heat once your punched through you can use a down cut the important thing is sharp.
I use the bit that mates to my radius. but you can use a 1/4 in. That leaves an 1/8 in radius in the corner if your using a 1/2 in pattern bit on the jig use that as the corner radii match.

again try taking a 1/16 at a pass cutting as fast as you can with the router as slow as it will go
you have my number call me

[Bob Gleason]

Thanks for the replies. I'll make a pile of plastic chips later this week.