Stuck Acrylic blank

Signed-In Members Don't See This Ad
Joined
Sep 9, 2019
Messages
10
Location
Virginia
My first attempt to make an acrylic pen. While drilling an acrylic pen blank the bit got stuck coming out. Is there any trick to get this stuck blank off the drill bit without destroying the blank? Its stuck pretty good.

Thanks
Roger
 
Signed-In Members Don't See This Ad

pshrynk

Member
Joined
Dec 6, 2017
Messages
742
Location
Lake City, Minnesota
That is one of the favorite ways of someone new to plastics to lose a blank. I did it twice the first two times I tried it. It sometimes comes down to losing the blank versus the bit. I grabbed the blank with a padded vise grip and twisted real hard with a pliers on the bit. Lots of swearing and muscle sweat later and I had the blank freed. And the bit was a write off. Fortunately it was a 7 mm and those things are sent out with "get started" pack a lot, so I'm not missing it. The second was with a much spendier bit, so I just sorta pounded it with a hammer until it split open and salvaged the bit.

Learned to do 3 things: 1) Make sure the bit is super sharp, 2) Use acrylic bits for plastics. You can get them from PSI. If you don't have the exact size, use a smaller one to make a pilot hole for the bigger, very sharp bit, and 3) Back out a lot and spray with soapy water to cool the bit and lubricate the hole. An auxiliary lesson was that when the bit starts squeaking, pull out and cool the bit.

Edit: I was typing the same time that John was. Essentially the same advice that.
 

WriteON

Member
Joined
Aug 21, 2013
Messages
3,266
Location
S. Florida
Been there a few times. I have souvenirs. They are fused together. I break the blank to save the bit. Take small advances and withdraw. Trying to drill too deep without withdrawing and cleaning bit & blank gets ugly when almost finished.
 

TonyL

Member
Joined
Mar 9, 2014
Messages
8,904
Location
Georgia
I would freeze it first. Then spray some wd40 in there. Having said that ...I had to cut mine off with a saw.
 

EricRN

Member
Joined
May 16, 2019
Messages
760
My first attempt to make an acrylic pen. While drilling an acrylic pen blank the bit got stuck coming out. Is there any trick to get this stuck blank off the drill bit without destroying the blank? Its stuck pretty good.

Thanks
Roger
Wouldn't be surprised if one of the threads linked to below is mine. Flood the hole with WD40; it'll help get the bit out. If you salvage the blank though, make sure you clean out the lube good. I did not and the thing blew apart on me while turning.

Have used lots of soapy water as a lubricant and also switched to Norseman bits and not had any issues since. Go slow. If you find yourself asking whether you can go just a bit further... you can't. Pull out. Spray with the soapy water. And dive back in.
 

penicillin

Member
Joined
Feb 27, 2019
Messages
1,036
I always drill a short distance, then pull the entire tailstock out and let the bit cool.

That is, I loosen the lock handle on the tailstock and pull it completely back while the lathe is turning. If you stop the lathe, the bit can get stuck, and certainly it will be much more difficult to back out.

After the bit is out, I backup the tailstock screw so that it is ready for the next small push. When the bit is cool, I turn on the lathe, then push the tailstock until the bit bottoms out in the back of the hole. I quickly lock the tailstock lever, crank the tailstock to drill another 1/2 inch or so, then repeat.

I do not run the lathe at high speed, but not at the slowest speed either. I use the Fisch pen blank drills for the most part. They are fancy brad point bits. I am undecided whether they are better than ordinary brad point bits or other bits for drilling pen blanks. I think not.

I have not needed a lubricant or coolant, and the process has worked well for me on standard "ribbon" type acrylics, the inlace acrylester, and similar plastic blanks.
 
Joined
Sep 9, 2019
Messages
10
Location
Virginia
Yes learned that the first time. Trashed the blank and saved the bit. (hammer, chisel, and a vise great tools) The Turncrafter Commander I originally
used yesterday would only go down to about 450 RPM. So I went to my NOVA Saturn and this lathe goes down to below 250 RPM. I drilled the blanks at 175 RPM. Much better luck. 1/4-1/2 inch at a time. Just like you said I pulled bit out to clean chips and cool the bit. Never got hot at the slow RPM and drilled perfect hole. Getting ready to put it n the small lathe and turn it. I am new at this and learning my retirement job.
Many thanks to all!!

Roger
 
Joined
Sep 9, 2019
Messages
10
Location
Virginia
It really helps when your learning and have this vast information data base and the folks here on this forum. So on my second attempt, I got to the finish line on this pen. Here s a PIC of the results. Thanks to all who helped.

Roger first acrylic pen.jpg
 

dogcatcher

Member
Joined
Jul 4, 2007
Messages
2,359
Location
TX, NM or on the road
When I drill acrylic and the resin blanks, I use auto transmission fluid as a cooling and drilling agent. Buy the cheap AFT fluid at the dollar stores and get squeeze bottles at Harbor Freight. Makes a mess, but it works. The first time will teach you to drill on a slow speed, eye protection is required.
 
Top Bottom