Blank seized my bit, now what?

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joefrog

joefrog

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Joined
Mar 14, 2012
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409
Location
Birmingham, AL area (Alabaster)
I was drilling a relatively expensive blank this morning, and it LOCKED my bit in. I tried putting it on the drill press, no dice -- still can't get it loose.

I hate, hate, HATE to lose this blank -- but is it Hammer Time? Options?

Thanks!
 
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Lathe off. Hold the end of the drill in your lathe chuck. Wear gloves or wrap the blank with a rag. Get someone to hold the chuck while you unscrew the blank from the drill. Good luck....:wink:
 
I've had that happen when the plastic gets too hot starts to melt and them basically re-hardens in the flutes of the drill bit. If that's what happened it's very very hard to get out without destroying the blank.
 
joefrog said:
Sorry, it's a segmented acrylic blank. One of these, tiny little pieces.

Pen Makers Choice Mosaic Acrylic Pen Blanks | Pen Making | Craft Supplies USA

I'll try the freezer trick in the meantime.
Click to expand...

The freezer is exactly the opposite of my suggestion.

Put it in a 200 degree oven for 15-20 minutes. Find a vice grip pliers and an oven mitt. Take the blank out of the oven, grab the drill bit with the vice grip and the blank with the oven mitt and turn them, reversing the bit out of the blank. IF it does not work the first time, leave it in the oven a little longer on the second try.

IF possible, do NOT raise the temp., But, if all else fails.......

When you get it out and get the blank tubed, douse the outside with thin CA a day or so before you turn it. Then, as you turn continue to use thin CA to reinforce.

Should work fine,

Ed
 
Twist it off...caused by several things...to high a speed, dull bit, poor angle, un-stable wood, or poor technique. Correct those and there should never be another problem.
 
One thing that worked for me in the past was once it seized I did put it in the freezer actually over night, when I took it out I immediately hit the blank with a butane tourch (lightly) the plastic will heat up / expand quicker than the steel which should help break it loose. It still may need the help of visegrips. I am glad this has never happened to me, Ha Ha!!
 
Listen to Ed!!!!! Your bit probably got stuck because it got hot either because it was dull, you were drilling to fast, or you were putting too much pressure on the drill bit, or a combination of these.

The bit got hot, melted the "Plastic" around the bit, bogged down and cooled, hardened around the bit, and you used colorful language.

The idea is to warm up the bit and the blank so you can back the bit out and save the blank. And.... sharpening the bit is a good idea anyway.

Listen to Ed, he knows alot about pen making and problem solving.

Ross
 
Well, I don't know how strong bonding the blank is made off so, I would consider and protect/strengthen that blank the best way I can before I cart twisting, bashing, pulling, pushing, etc. so, I would use medium CA and some masking tape to created a solid wrap around the blank, spread some medium CA at half of the blanks and wrap a couple of layers with the masking tape, repeat the process on the other half, use thin CA to coat the whole tape surface to create a hard, stable protecting cover to that blank.

Now, is my believe that, the plastic melted inside the drill bit flutes, bonding with the inside of the blank so, based on that believe, heat is the way to reverse the process so, when the CA on the tape of the blank is dry/set, put it in a vice making sure the blanks top is level with the vice jaws, (this is when a aluminium angle set of jaw covers would be handy...!).

Use a vice clamp and attach it to the top end of the drill bit, make it quite firm grip (use some masking tape on the drill bit to protect it), now you need a small torch flame to heat the drill bit as close as possible to the blank but not touching it.

Allow the colour of the hot drill bit to go red and downwards, keep one hand on the clamp vice and put a slight pressure on it in the reverse orientation, don't force it but maintain some pressure so that, as soon as the heat spreads to the bit area that is stuck, the plastic will soften/melt and you can put the torch away and quickly (before the heat starts to dissipate) , continue untwisting the drill bit until is all out.

Heat and a steel brush will remove ant melted plastic from the drill bit, as for the blank, the end close to the torch my be a little burl but not spoiling it, you will need to re-drill it so, make sure the bit you are using is sharp, go slow and remove bit before it get hot inside the blank, keep all the wrapping on that blank, it is the only thing you have to maintain its structure integrity, it will come out when you start turning it.

It wouldn't hurt to soak the drilled hole with this CA, let dry, re-drill to clean up for the tube to fit.

After the blanks went from square to round, stop the lathe and inspect the blank, with some magnification if available, to give you some piece of mind, put a layer thin CA all over the blank, it there is a minor separation somewhere, you will notice the CA to disappear into that small crack(s), in that case, pour some more thin CA until it absorbs no more, spray some accelerator on it or, let it harden or use a hair drier/heat gun to accelerate the drying process and, continue on...!

This is what I would do if I wanted to save the blanks or avoid unnecessary damage to it...!

Good luck,
Cheers
George
 
the oven trick is the best for sure....I've tried both and the oven worked every time....oh, and making sure I was using a sharp bit.
 
Haven't tried the oven, but that sounds like the trick to me. I've done the torch thing and was able to remove the bit -- sorta dicy though. :eek: A little more controlled heat sounds reasonable.

As above, thin CA after you get the bit out to stabilize and fill any voids.
 
This happened to me once, of course it was a cheap blank so experimentation was in order. I found out that if I heated up the drill itself slowly while keeping the blank cool (kept the blank immersed in cool tap water) I was able after a period of about 15-20 minutes to extract the bit by turning it in reverse with a pair of pliers.

Hope it helps.
 
Make sure you back he bit out frequently as well when drilling plastics. No matter how sharp the drill is, once it gets loaded up and the plastic starts to cool away from the cutting edge it will bond to the drill.
 
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