yet another "removing stuck chuck" question

[J Tiers]

Got a "nice" LW dividing head today.

Cleaning it up, I found that it does have the inevitable one serious problem.

The chuck (1 1/2-8, apparently) is stuck, and isn't wanting to come off. Looks like it might have some rust in that area, although the rest of the "rust" was really just discolored and solidified grease or oil.

I have various concoctions for loosening rust, P'blaster, etc.

The question is how to apply force without risking damage to the worm setup. I don't think I want to pull the spindle if I don't have to, as it's not loose, seems OK. I'd have to take off the gear, and the rear nut, etc, which seems excessive....

I can set up on the spindle lock, but that doesn't seem to make it particularly any safer to reef on or "tunk" on the chuck (or on a piece of hex clamped in it, actually). I kinda need to get the chuck off for cleaning and/or disposal, I think its junk.

Not much spindle sticking out....

Ideas?

[Paul Alciatore]

I think you are right in not wanting to risk damaging the worm. If there is enough spindle available behind the chuck (1/4" or so) I would try to fabricate a strap wrench with steel strap and a piece of stock of the same width.

Of course, you should soak it in your favorite penetrating oil for a while first.

Paul A.

[Bruce Griffing]

Can you disassemble the chuck in place? If you can remove the gear sleve, thread and jaws, you will have easier access to the back of the chuck. It may be open the the threads or you may have to drill into it. Access to the other end of the thread will allow you to try lubrication first. Failing that, I would try cut the chuck body in half without going down to the threads.

[drof34]

If your L&W dividing head is like mine,then the worm is on an eccentric which which can be rotated out of mesh with the worm gear and consequently pulled out of the housing.

It's pretty straight forward except for two set screws in the top of the housing that are perpendicular to the worm shaft. Their function is to keep the worm shaft bearing,which contains the eccentric,where you set it.

There is no roller bearing on the spindle,just bare metal to metal.The back bearing is just a straight bore while the front big bearing is tapered.The lock is just a screw pushing against a brass plug that pushes against the tapered bearing.I don't remember whether the thrust bearing is a brass washer or what.

If it were me I think I would pull the worm out and run one jaw about flush with the OD and flail the hell out of it,in a counter clockwise direction of course and after it was saturated with P oil.

Jim W.

[nheng]

JT: Does the worm have a little bit of backlash to work with ... if so how about if you tighten the lock with the backlash NOT taken up (in the unscrew direction). Then, apply gentle "impact wrench" style taps somewhere on the circumference with a brass or aluminum bar.

After a few test "taps" loosen the lock and see if the backlash is still there. If so, the lock protected the worm against the taps ... tap on, continuing to check periodically for the sake of the worm.

Den

[J Tiers]

drof: I don't think it is like yours. There is just one (double stacked) setscrew in the top, and the other pic shows the plate side has a bolt-on piece.. no sign of an eccentric that I can see.

As you can see. not much to grab anywhere. Might have to figure out how to get it out so I can hold the spindle.

In the first pic, the object along the bottom is a 6" rule that didn't get quite in the pic.

http://img4.photobucket.com/albums/0...y/lwinsids.jpg

http://img4.photobucket.com/albums/0...ey/lwfrnts.jpg

Also, looking at the first pic, there is a hole at the bottom. The bracket (one side, not double) has got a hole corresponding. Do you suppose it would have had a detent? Neither hole goes through.

Thanks
JT

[G.A. Ewen]

If you are ABSOLUTLY SURE that it is threaded on you can try this. It has worked for me every time.

[Mike Burdick]

G.A.,

Now that's clever! When one sees a good idea no words needed.

(should put that in the tips book)

-Mike

[J Tiers]

And I would if it were a lathe. But that worm and gear has me worrited. I don't want to strip teeth.

It is kinda like using back-gear for a lock, which wouldn't be too cool with impacts. Only I can't disengage the gears and use the rotating pulley mass as a counterpoise, as I might with the lathe. There isn't any mass to speak of, aside from the chuck.

I am not even too sure how to disassemble the thing further, even though it is pretty simple appearing.

And, of course, I have something for it to do, scheduled for the day before yesterday....so a chance of damage isn't really wanted. This stuck chuck was a surprise I didn't need.

I figured I could get it off and put a good chuck on it, grease and oil it, and get going. A full clean and so forth could wait until I had cut the one gear I need to cut....

[G.A. Ewen]

Mike,
One pull of the trigger is all it takes (about 30 seconds) The last time that I had to remove a stuck chuck was for a friend. He had got a bit hyper before calling me and had broken 4 teeth off on his back gear. He almost cried when he saw how easily it came off with the air chisel.

Neil can use it in the tricks book if he likes.