How to unstick drill bit from acrylic blank?

[KP]

Folks - I was drilling an acrylic blank for a long click, and the bit got stuck when I got deep into the blank. I'd like to save the bit, 'cause it's a good brad-point, and, if possible, also the blank (My daughter chose this one). Ideas on separating the dang thing? Thanks -

Ken

 

[Wheaties]

Usually twisting in the opposite direction will get it out

 

[ed4copies]

You can warm it, in the oven, about 150 degrees for a while (15-20 minutes) then use an "ove-glove" or equivalent and a vice grip (on the drill shank) and back it out. Let the blank cool and you're back in business.

Now, you know why we say back your drill bit out frequently (so you still CAN).

 

[jack barnes]

been there and done that what Ed said use toaster oven

Jack

 

[TellicoTurning]

You can warm it, in the oven, about 150 degrees for a while (15-20 minutes) then use an "ove-glove" or equivalent and a vice grip (on the drill shank) and back it out. Let the blank cool and you're back in business.

Now, you know why we say back your drill bit out frequently (so you still CAN).

Wish I had know this a while back... did the same thing... got too aggressive and waited too long to back out of the blank... I wound up taking a hammer and cracking the blank off the bit.:frown:. really hard on the blanks when you have to do that.... :redface:

I also got a spade bit stuck in a peppermill blank once....... you can't take a hammer to a 4" square chunk of wood.... that one took a while to work the bit out..

Now I remember to back out of the drill hole frequently and clear the debris...

 

[skiprat]

Also try to unscrew it to match the drill bit flute helix once you have warmed it. In other words, pull it while turning the drill backwards.
The debris will be melted inside the flutes and just twisting it will probably break the blank. DAMHIKT:redface:
Good luck:wink:

 

[KP]

Thanks folks. The temp change and using my hand drill clamps on the bit as hard as I could did the trick. There was a nice crack as it let go, but the blank was ok, so I guess that was the melted stuff in the flutes breaking free. I also tried the drill first on forward, then backwards, might have helped.

Filed the scoring off the bit, back in business, saved a $10 drill bit and a $3 blank. Small victories, that's the ticket....

Ken

 

[ed4copies]

'Spose you don't wanna hear, "Retract the drill bit frequently and empty the hole"??

 

[DennisM]

'Spose you don't wanna hear, "Retract the drill bit frequently and empty the hole"??

Also Go Slow! Slower.... Even Slower...

I have also started to use a little plastic polish on the bit as drilling really hard blanks. Keeps it cool and helps the shavings run out..

 

[Daniel]

Chuck, getting a spade bit stuck is not that hard to do. they are pretty prone to it since they can pile up so much waste behind them compared to other bits. so don't kick yourself to hard for that one. I got one stuck in a beam in the attic of a house once. Far as I know it is still there. basically it was in a tight spot and wasn't worth the fight to get back.

 

[TellicoTurning]

Chuck, getting a spade bit stuck is not that hard to do. they are pretty prone to it since they can pile up so much waste behind them compared to other bits. so don't kick yourself to hard for that one. I got one stuck in a beam in the attic of a house once. Far as I know it is still there. basically it was in a tight spot and wasn't worth the fight to get back.

I wasn't so much concerned about the bit as I was the mill blank... I think it was a chunk of wood I'd paid close to $30 for and I wanted to save it... I don't use spade bits on pepper mills any more.

 

[snyiper]

When drilling acrylic I use a spray bottle of water.

 

[Super Dave]

WD 40 worked when it happened to me.

Dave

 

[KP]

This was indeed my first acrylic, but I'd read many threads here about going slow, and believed them. Actually, I had been going pretty slow, or thought I was. I'd been drilling maybe 1/2 to 3/4 inch at a time, retract, and then let bit and blank cool for a couple minutes. I think what got me into trouble was that this was a blank for a long click, and I don't have any bits long enough to keep the flutes clear of the blank when I'm getting close to the full length. So, I end up finishing the drilling by pulling the bit farther out of the chuck and getting the bit in deeper than the flutes. On wood, I've not had a problem, but I guess the acrylic heated up fast when the shavings couldn't get out, and melted to the sides of the hole.

Once I got the bit free, I still had to drill maybe an inch into the blank. I did it maybe an 1/8" at a time, retract, let cool, etc.

Oh, yeah, I'm a believer now.......

Ken

 

[ed4copies]

Well, Ken,

IMO!!!! Drill at about 1000 rpm (NOT too slow).
For very deep holes, put cool water in the hole, change the water every inch or so of drill penetration (retract drill bit every half inch or less) And, of course, DON'T drill through, cut off the end.

Follow these guidelines and you will never lose another bit, once in a while, you will still ruin a blank--but SELDOM.

REMEMBER this advice is worth EVERY penny you paid for it!!!

Good luck, have fun, have two of every size bit, so you can continue to the next blank!!

 

[wyone]

I guess I have been lucky.. so far have not gotten a bit stuck.. but I use an air blower pretty much continuously as I drill, raising up to blow out the chips VERY often. It is a bit awkward, the point I have thought of making a foot air switch and a stationary nozzle on my drill press.

 

[t001xa22]

I have had my best luck drilling acrylics by using a sharp twist bit, lubricating the bore with each round using dishwashing liquid/water, blowing out the bore each time with air, and limiting my round to about 1/4"-3/8". I still use brad-point bits on woods, but have found that these bits, of course, are very aggressive and want to pull in on their own, somewhat.

 

[WriteON]

Just when I thought everything was under control. Hello trash can.

 

[Fay Prozora]

I have been very fortunate that I haven't had this happen but I did have a little bit of trouble with the wood burning, but that pen came out pretty nice and you can't even tell it had burned. when using acrylics, I like to use a pipe cleaner to clean out all the debris from the hole but I do that when the blank is cool. I do that even on my wooden pen blanks or any thing that I have to drill a hole in. It's been awhile since I used acrylics and I have some coming next week.. Fay

 

[lteton]

Had this happen to me the other day on a perfume pen. Broke the acrylic off. Had a similar problem with another. I was only advancing around a quarter inch at a time and still having problems I think because the depth of the hole was more than my fluke length. I went to a local tool supplier (Beaver Tool) and told them I needed a bit for plastic with at least 3 1/2" flukes. They supplied me with one for about $9 and while I haven't tried it, I believe I could drill the whole depth in one go if I wanted. I'm drilling 1/2" and 3/4' at a time with no problem. Not hot at all. Well worth the price.

 

[t001xa22]

One thing I have found out over time: even when you have a bit long enough to complete a particular bore, the thing to watch out for is when the twist flukes finally sink below the bore hole. Once a boring reaches that point, none of the waste can be carried out with the bit rotation. So, this usually means having to retract and dump the waste more often.