Author Topic: Stuck drill fragment -HELP!  (Read 3425 times)

Offline kvom

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Stuck drill fragment -HELP!
« on: August 09, 2015, 11:36:07 PM »


1/8" cobalt twist drill broken in through hole in CI.  There's only about 1/8" of the drill still stuck, but it's resisted pressing out with vise and arbor press.  Also broke a carbide EM trying to drill it out.  Heated with a torch a bit but probably not enough.  Could resort to 20-ton shop press.

Any ideas.  I have a day's work already in the piece and would prefer not to have to make another.   :shrug:  :headscratch:

Online b.lindsey

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Re: Stuck drill fragment -HELP!
« Reply #1 on: August 09, 2015, 11:58:39 PM »
Is there enough sticking out there on the inside of the steam chest to grab like with small vise grips and possible get it to twist enough to back it out after spraying it first with WD 40 or PB Blaster or something like that. I am afraid the 20 ton press may break the CI. Know anyone with a ram type EDM? Not the fastest solution but it will burn it out.  Bummer when that happens and it always seem to be after a full day's work invested too. I feel your pain  :(

Bill

Offline mklotz

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Re: Stuck drill fragment -HELP!
« Reply #2 on: August 10, 2015, 12:42:33 AM »
Do you happen to have one of those vibrator type engraving tools?  If so, try oiling everything up with Kroil and then "tattooing" the drill stub.  I've had (limited) success unsticking broken drills this way.  May not work but worth a try if you have  the tool.

This trick also works on frozen nuts.  Sometimes it's necessary to use a Dremel to form a depression into which the vibrator tip can seat.  This prevents the vibrator from "skating" over the offending bit and concentrates the vibrations in the direction needed to unstick the part.
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Offline peatoluser

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Re: Stuck drill fragment -HELP!
« Reply #3 on: August 10, 2015, 11:43:48 AM »
I'm assuming thats a piece of the drill sticking thru' into the cavity. You could try putting a piece of square steel through the valve chest, open up the bench vice enough to rest the ends of the bar on top or the vice jaws with the drill tip sitting on top of the square bar. Then place a nut or a small socket to fit over the drill on the outside. Give the nut/socket a smartest blow with a hammer. This way you are trying to knock the drill out in the opposite way that it went in. It might just dislodge it enough for some of the other ideas to work. A piece of HSS might be best to use as the 'anvil' so you won't be driving the tip of the drill into some BMS.

you might be able to grind it out with a very small diamond burr in a dremel or proton type tool . Although I can imagine this being quite time consuming.

good luck with which ever method you use and I hope you can salvage the part

yours peter

Offline Vixen

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Re: Stuck drill fragment -HELP!
« Reply #4 on: August 10, 2015, 12:51:06 PM »
You have a bit of a dilemma, I fear.
You have tried all the quick fixes without success. I you are not carefull you can easily waste a further day or two trying to avoid the one day lost in making another.

Good luck

Mike
It is the journey that matters, not the destination

Online Stuart

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Re: Stuck drill fragment -HELP!
« Reply #5 on: August 10, 2015, 01:02:34 PM »
Make up a hollow drill out of silver steel ,like a spot face one

Then core out the drill as it CI should go ok the bore , tap the hole and fit a plug and start again


Stuart
My aim is for a accurate part with a good finish

Online Jo

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Re: Stuck drill fragment -HELP!
« Reply #6 on: August 10, 2015, 01:08:33 PM »
CI is normally self lubricating so things don't usually get stuck  :noidea:

Hollow drills sometimes work  :ThumbsUp:

The other thing to think about is you can get at the bottom of the drill.... so you can also try pushing it up rather than down. My guess is that the bit of swarf doing the jamming migh be jammed harder one way than the other.

Good luck.

Jo
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Offline kvom

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Re: Stuck drill fragment -HELP!
« Reply #7 on: August 10, 2015, 02:15:10 PM »
We have a winner -  Had same advice as Jo's as well on another forum.  Bar of steel through the cavity against the broken top, and two other bars on each side against vise jaws, and it popped free!   :whoohoo:

Online b.lindsey

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Re: Stuck drill fragment -HELP!
« Reply #8 on: August 10, 2015, 04:22:49 PM »
Nice save kvom :)

Bill