drilling for router bushings?

[Rick Potter]

Any suggestions on how to drill the proper stepped hole in custom router bases for standard PC bushings??

I tried hole saws..pretty rough, and I don't really have the right sizes. I tried spade bits and forstner bits but they really have a hard time with the acrylic.

I have several trim routers that I want to make custom bases for.

Rick Potter

[Ben Hatcher]

Try a sharp forstner bit on a very slow speed and use a lubricant like vaseline.

[Tom Cornish]

+1 - a couple hundred RPM with a reasonably sharp bit works fine.

[Justin Chen]

You could also make a template and use a straight router bit with bushing. I know when acrylic routes pretty smoothly.

[Lee Schierer]

Instead of acrylic try polycarbonate (Lexan) it is easier to work with and less likely to crack.

[Rick Potter]

Lee,
You made me go look. I have several scraps of this stuff I picked up 10 years ago, 3/16, 1/4 and 3/8". The protective cover on the 3/8 says 'carbonate', and I had written 'polycarbonate' on it when I got it. The other scraps have 'acrylic' or 'acrylic GP' in various places. Hard to tell more, since the pieces are each about the size to make a router base.

Ben and Tom,
I will try that tip with a small scrap today. Thanks.

Justin,
A router? It works? Since I was melting it with everything else I tried, I never thought to use a router. Tell me you're not joshing me!

Rick Potter

[Norman Hitt]

Note: (This is just a thinking/musing out side the box), but.... I wonder if there is a "Step Drill Bit" that is the proper size, and if so, I wonder if it would work using a slow speed on a drill press for just the last pass to make the flat bottom countersunk portion without the melting problem, after drilling the slightly smaller hole that goes all the way through with a hole saw or other kind of bit???

[Lee Schierer]

Lee, Hard to tell more, since the pieces are each about the size to make a router base.
Rick Potter

If you look at the edges of the plastic the polycarbonate will be a grayish tint, the acrylic will be white.

[Myk Rian]

I use Forstner bits to make them. Had to open up the inner diameter a bit with a small sanding drum to get the guide to fit in. It is centered by the threaded ring on the bottom.
This one was made out of 3/8" phenolic. I am considering selling 10"x12" pieces for a small fee.