[PSDkevin]

Anyone have any suggestions for drilling acrylic blanks? Do I need some plastic bits? How about those colt bits? They look good but there are mixed reviews out there. Sorry to shotgun blast the questions.

 

[sawdustfactory]

Just go slow.

 

[Dave Paine]

+1 about going slow.

I have Colt brad point bits, with the double spiral. I have only used in wood. I like them.

I also have Colt Maxi-Cut Forstner bit, also only used in wood. I LOVE these.

The reason for going slow is to minimize heat. If too much heat, the acryllic will melt rather than cut and you will not like the result.

I would experiment if possible on a scrap piece, to test type of bit, feed rate etc.

I would also slow down the drill press to about 500 rpm.

 

[RusDemka]

Very slow and clean off chips often

 

[duncsuss]

Even with the drill press at its lowest setting I've had blanks blow out due to heat build up.

My method:

1) never use brad point bits
2) slowest setting on the drill press
3) only advance the bit 1/4 inch into to blank before backing out
4) use WATER -- I have a few syringes I fill with cold water and dribble into the hole, each time I back out the bit I fill it up to the top with more water

You need plenty of paper towels, and there can be a little spray -- but you were wearing your safety glasses anyway, weren't you :yes:

 

[Itchytoe]

I normally do it on my lathe, at about 500 rpm. Slow and steady, back out to clear debris often and you should get a nice clean hole.

 

[RusDemka]

I normally do it on my lathe, at about 500 rpm. Slow and steady, back out to clear debris often and you should get a nice clean hole.

I should try it on the lathe...

 

[davidpensfan87]

Woodcraft sells a great bit. I believe they are Woodriver brand. Brad point bits are a must as they prevent blowout, especially in acrylic. Hope this helps.
David.

 

[Ibangwood]

Any bit will do just drill so slow and eject the chips every 1/4" problem solved

 

[lion6255]

Go slow,Back out often,keep tools very very sharp.....I even take breaks and go do something else to let the blank cool down. Heat is is NOT your friend.

 

[Gary Beasley]

Second the use of water. You can also stop the drill a sixteenth shy of going through and trim the end off if you consistantly have problems with catches and splitting out when drilling through.

 

[Ibangwood]

Drilled over 100 acrylics, some guys go over kill with suggestions, literally sharp bit eject frequently, don't need to use water nor take a break, your bit or blank would hear would NOT heat up if you drill slow and eject your chips SIMPLE , brad point bit, never had one crack

 

[cabinetman]

Lotsa good suggestions so far. I would only use blanks that are cast acrylic, not extruded. They look the same, but machine differently. I agree, any sharp drill bit will work if used slow. If you have a drifting problem at the start, place the bit to the mark and turn the bit backwards for several turns just to make a starting divot.

.

 

[Huey]

Hi All
Thats the secret go at a slower n steady feed on the drill press I found doing it on the lathe was not that successful unless you have the right chuck jaws to hold your work peace nice n square.
Good Luck
Huey