Chamfer acrylic...

[Gene Buckle]

Has anyone tried putting a 45 degree chamfer in acrylic with any success? I need to do this for a project I'm working on and I don't want to ruin the part - do you need to ramp down the router speed or can you let it run full out?

Thanks all!

g.

[Bob Fraser]

Depending on the size of your project,
I have had the best results by doing it by hand.

You can plane an edge close to what you want, slowly.
Or you can use the edge of a chisel or cabinet scraper.

Too fast will chip or gouge small pieces out of the edge, even by hand.

Then when you are close to what you want use a sanding block,
bring it up to a final finish of 600 grit, then power buff.

bob

[Conrad Fiore]

Gene,
How thick is the acrylic, and do you want the chamfer to extend the full thickness, or somewhere short? What tools do you have at your disposal, router table, table saw?

[Gene Buckle]

The material is .25" thick and the chamfer needs to leave about .062" of material untouched.

The end result should look like this:

http://www.geneb.org/frame_example.jpg

The acrylic will be laser cut, but the laser can't do the chamfer for me. :) I don't want to try it by hand-carving as it needs to be 100% uniform around the inside perimeter.

Thanks!

g.

[Robert Reece]

I have made a few router bases over the years out of acrylic (Plexiglas G I think). I always chamfer the edges slightly with a 45 chamfer bit. I have never made a chamfer as deep as yours though. The one problem I see there is that the bit won't be able to ride on that small of ledge that you are leaving so you'll need to have a mating part that can guide the chamfer bit.
I am not sure how you would align the two parts to ensure you keep a 0.062" edge, that is pretty tight tolerance stuff.
I don't believe I adjusted the router speed, so I'd say full out. But the acrylic will melt so you better keep it moving and maybe take light passes.
As I think about it, you could make a guide by sticking a piece of 1/2" MDF to the acrylic and then use a pattern bit to match your opening. Obviously you would want to rough out the MDF before you attached it. This would effectively extend the material that the chamfer bit bearing could ride on.

[Gene Buckle]

Thanks Robert. I'll give that a shot and see how it goes. With any luck I'll remember to post a picture of the result. :)

g.

[Cliff Rohrabacher]

You will have a serious problem with stress introduced by any machining operation.

This won't be the case if you can use PolyCarbonate
But Alcrylic will need to be put in a stress relieving oven over night

[pat warner]

No surprises here (http://patwarner.com/images/fig20b.jpg). Use a new cutter at full speed.
Maybe take a swipe or 2 on scrap first.
Do expect to have chip every which way and may even foul the footway of the router itself.