Stuck Lathe Chuck

[vocatexas]

A few months ago I bought a large Lodge and Shipley lathe (36x72 inch). I'm in the process of finishing my shop, and when it's done I intend to disassemble this machine and go through it. It was built in 1917 and has sat unused most of it's life and, while it seems to be in over-all decent condition, most moving parts were stuck. In preparation of restoring it I've got everything movable now with the exception of the cross-slide. Out of curiosity today I decided to try to loosen the chuck. It appears to screw onto the spindle but I can't budge it; not even with a long bar chucked up. I'm almost certain this machine has babbitt bearings so I'm a bit hesitant to use heat, but I'm not sure how else I'm going to get it loose. By the way, it's a 24 1/2 inch 4 jaw. The machine isn't currently powered.

 

[Bob Korves]

Don't use heat on the spindle. Use cold on the spindle. Use a light amount of heat on the chuck. For cold, use dry ice in the spindle. A friend did that recently on his lathe of similar size and vintage for the same problem. No luck until he used both the heat and cold.

 

[vocatexas]

Bob, thanks for the reply. No, I would not directly heat the spindle, I would heat the chuck to expand it. I was just worried about transferring the heat from the chuck to the spindle, thence to the bearings. I hadn't thought about dry ice on the spindle. It's not available in my area, but I know a friend of mine uses it in his winery from time to time. I'll have to find out where he gets it.

Thanks!

 

[Bob Korves]

Whatever you do, do not use back gears to hold the spindle still. It is quite likely you will break teeth off if you do that.

 

[markba633csi]

Soak it for at least a week with penetrating solvent before you try to remove it

 

[brino]

A search here for "stuck chuck" will find dozens of hits. Some of them have some very useful and creative advice.

My favorites:
-lots of penetrating oil applied over a period of weeks
-a good safe way to lock the spindle; like a split wedge bar that locks inside the spindle from the out-board end
-a hex bar tightened in the chuck, with a socket and air ratchet on the hex bar to loosen (a thousand little blows vs. a few big ones)

also be sure to have some protection for the ways so that wrenches, bars and the chuck itself don't ding it up.

Wow a 24 inch chuck!
hopefully you have a safe way to lift it too.

-brino

 

[benmychree]

In my shop I had a 30" swing American lathe with geared head; to remove the 30" chuck, I would put it in the lowest speed in reverse, and put a 4X4 between the bed way and one of the chuck jaws and engage the clutch and bump it until the chuck started to unscrew.
When I worked at Kaiser Steel, we had a 36" Nebel lathe that I had to remove the 4 jaw chuck and put on a faceplate with chuck jaws to work on a larger part, and tried the 4X4 method, and made a bunch of kindling; finally I had to insert a 4" square boring bar diagonally through to chuck jaws and downward between the ways and bump the direct connected (no clutch) motor (30HP) multiple times to break it loose.

 

[vocatexas]

I had read that using back gears was a bad idea, but thanks for mentioning it. Someone else might read this and not know that. I've been soaking almost every moving part on this machine with Liquid Wrench for about a month. I should buy stock in Liquid Wrench. I've used nearly two cases of it so far. It's done a great job on most parts, but not the chuck or cross-slide. I tried putting a wooden wedge between the bull gear and drive gear and used a pry bar to pull on the chuck. I found out how toothpicks are made...The bull gear is around 24 inches in diameter.

 

[benmychree]

I have a 9" Monarch lathe about the same vintage as your lathe that had a broken tooth on the cone pulley back gear, I figure that it was broken by using a wrench on a chuck jaw and hammering on it; I repaired it by turning the teeth off the gear and turning it undersize and making a new gear to press over the remains of the old gear and pinning it on like a keyway. My go to method of removing chucks is to put the lathe on back gear with the belt on the largest step on the cone pulley and pulling the belt down on the backside with of course a wood block under the chuck jaw. For my gear head Regal, I put it in the lowest gear speed and use the wood block under the chuck jaw and bump the motor; I have made a quantity of kindling over the years, but never broke anything. I think that rust does not much get into threads on a spindle, but it is the constant hammering of (especially) interrupted cuts that gets chucks on so tight. I would not worry about babbit bearings on that lathe, likely they are bronze; I have only ever seen one lathe where the bearings were babbited, it was a Leblond from about the WW-1 era, and they were poured in the rough casting, not in shells.

 

[jcp]

John......The shop I worked in had an American 30" with a 10.5" hollow spindle, double chuck oil field lathe. 10' bed I think. We needed to remove the bed side chuck to fish out a chip in the labyrinth spindle seal that was pumping out oil almost as fast as we poured it in. We tried several methods to no avail. Chuck is still on there. That was about 25 years ago. Shop is still using the lathe.