Stuck Drill chuck in Mill

The_Apprentice

Registered
Registered
Joined
Jun 14, 2017
Messages
263
So, I thought my problems of WEDGED CHUCKS were behind me by now. But no, I have yet a similar issue to handle with my Mini-Mill.

So, I've tried losening the drawbar and giving it multiple hard wacks with the mallet. No go. I even tried a traditional iron hammer after getting desperate. Nope, damn thing won't budge. Now I'm really starting to worry.

Unlike with lathes, I will not be able to target specific areas with heat to loosen things up. Well, maybe I can if I dissasemble the unit. I guess that could be an option.

Other ideas I had were spraying WD40 down the top, and hoping for a miracle there.

Last option, I can just leave things as is, and just place my end-mills into the actual drill chuck when working. Seems that works fine for every self-declared expert on youtube, despite the manual clearly states to never do this!

Any other ideas? LOL

It's just a 3MT here, very impressive how stuck it got. Seems main problems everyone else has with these is the opposite.
 
Get a can of co2 duster turn it upsidedown and spray the chuck down. Then wack it out.
I think this idea has some merit. But I'd go a step further. Get a suitable set of Jacobs taper (ie, chuck) wedges, and get the chuck off the MT3-JT[whatever] arbor. Then get a thin sheet of foam rubber (or even corrugated cardboard), cut a hole in it to just clear the JT stub, and hold or attach it at the top of the JT stub to shield the spindle. THEN direct the CO2 spray onto the JT stub. This should do a better job of selectively cooling the arbor.

Alternatively, you could get some penetrating oil (or the classic homebrew of acetone and ATF), apply liberally into the spindle, and gently heat the chuck/arbor/spindle a few times over a couple days to help the oil penetrate. If this fails, then try chilling the arbor.

I'd shy away from whacking too hard, as this might cause damage to the spindle bearings. Best wishes for a successful removal!
 
This is a good time to apply the "stop and think" approach.

Could you post a picture (share the make/model for a close enough internet picture) of the actual set up? Do you have any history of when / how this got stuck (is this your mill for a while or did you just get it)? Has that tool been in there "forever"? Is there any chance that the tool spun in the machine taper? The more you know about the actual issues, the better you (or anybody else) can plan what to do next.

BobK's advise about supporting the spindle is very sound advise - protect those bearings!

Beating on the actual drawbar is fine - so long as the tool is not really stuck. Beating on the threads is not so good if it is really stuck. Like "Cat" said, make up a heavier punch, threaded a bit on the one end - with a projection on the lower end that will bottom out in the pocket of the arbor (only make this new punch snug since tightened threads, or putting the force directly through the threads will slightly swell the arbor - the more force you put the tighter it sticks).

Can you get some liquid nitrogen? Make up a tube and pour some down into the threaded pocket of the tool - enough that you actually get liquid down there as it will be flashing like crazy in the tube, but not enough that you cool off the spindle.

Can you make up a "strong back" - just a bar and long ready rods with another bar across the bottom. Then you load up with your favorite penetrating oil, put some pressure on and leave it for a couple days, then try a few more whacks with a hammer.

Let us know how you make out. David
 
First I would soak it with kroil and just tap the chuck with brass hammer to make vibrations so it will creep. Then the next day try again . Till it pops out. After its out I'd find why it stuck ??? . In fifty years I've never stuck a morse taper . Somethings wrong , they don't need tons of torque to hold them in . Did it spin in use causing gulling ,, welding itself ,,, there's a reason but what.
 
Well, I haven't used Liquid Nitro since my university days.... But I did pick up some Liquid Wrench Penetrating Oil. Worth a shot?

I actually still have Liquid Wrench chain-lube, as I hear from some experienced users it does wonders for the plastic gears and rubber pulleys on mini-lathes. I use it for some other things as well, so I'm ok with the name-brand.

I'll do a little bit of squirting with the oil over the rest of the week, and a little taps here and there. I'm not expecting much, but we'll just have to take it a bit at a time.

I did take a look at some youtube videos, but dear god. Some of these videos I could swear are by people who have no business in the world telling people how to work or maintain their mills. Some I can not even tell if they are serious or just trolling. LOL

I should post some samples, just for newbies to watch as part of an exercise to spot on what "NOT TO DO!" And yes, I am actually serious here.

That said, the machine is new of course. But who knows how long items may have been sitting somewhere getting corroded in unprotected bits.

I will keep this updated...
 
I"m not familiar with your mill, but is the drill chuck in a collet, or does it fit into a taper? If a collet, just unscrew the drawbar until the collet comes loose, Catch it before it falls on the mill table or vise, though.
 
Like Chipper5783 said it would be helpful for pictures and a little more information---is your mt3 for a drawbar with threads or just solid or with a tang-is there a slot in the spindle for a wedged drift tool?--liquid wrench is my favorite but give it a day to work in good---you could use an air hammer with a hammer type head to get some good vibration along with many quick blows and then try a good heavier blow---Dave
 
Back
Top