Drilling Acrylics with a hollow chisel mortiser

[pensmyth]

I wasn't sure which forum to post this under so I figured I'd try this one.
I'm working on several ideas for some inlays for some future pen blanks and was wondering. Can you drill an acrylic blank with a hollow chisel mortiser. I'm wanting to make a square hole in the body of the blank. Will it work just like with a wood blank or will it be to brittle...

 

[BigguyZ]

I don't think you would have a chisel sharp enough to cleanly cut through the acrylic. But you can always try...

 

[KenV]

Have not tried it - high risk of chipping based on how a hollow mortice machine works. Center drill bores a round hole and the corners cut by chisel action. Easy test is to use a corner chisel or veiner to cut the corner on a cut off of acrylic. We can be pretty sure the drilling part is practical given heat challenges, but the cutting of the corners???

There is an old fashioned approach of the square broach to make a square hole out of a round hole, or the square rasp/file combination.

 

[Texatdurango]

I used my mortising drill when making some segmented designs in wood blanks with great sucess but can only imagine shards of broken material flying around if I tried it with acrylic.

I have found however that Alumalite tends to be a little soft right after casting so it might be something to consider using. You might be able to drill a hole before it totally sets up OR you could just place a square plug of delrin into the mold while pouring then just pop the plug out when finished to reveal a square hole in your blank.

 

[JerrySambrook]

You may also want to worry about the speed that the drill has.
This may cause a problem with the acrylis as well

Some of the benchtop ones are high rpm machines.