Lathe chuck removal

[Mr Ron]

Back in the days before D-1 chucks, chucks were fitted to a threaded spindle, via a back plate. They were sometimes hard to remove. I have been cautioned against engaging the back gears as an aid in removing a chuck. Teeth on the back gear can get sheared off in the process. There have been several ways advanced using wood wedges, levers, etc. What is the best way you old timers used to remove tight chucks? I sometimes have this problem and don't want to risk damaging anything.

[ronm]

This should get you started...(it has been discussed before...)
http://www.chaski.org/homemachinist/sea ... mit=Search

[dly31]

I have had good results from spinning the spindle backwards by hand and suddenly stopping the chuck by letting a jaw hit a heavy wood block on the back side. I have thought about a 'wrench' to fit over all three jaws and a short 'handle' to take the impact.

The forums are full of ideas; some use the back gears and 'have never heard of them being damaged'. There are plenty of first hand reports of broken back gears from attempts to remove a stuck chuck. I normally use my back gears to remove the chuck but not when it is stuck.

[OlderNewbie]

Somewhere or another--it might have been here--I saw that someone made a wrench that attaches to the left end of the spindle using a split collar that had a 3' or so bar threaded into it normal to the spindle axis. It provided plenty of leverage when worked against another bar placed between the jaws of the chuck. I'd probably try a strap wrench on the chuck to avoid overstressing the jaws, but that might not be necessary (and you couldn't get as much torque that way).

John

[scmods]

Mr. Ron, and I am sure others.

Back before stud camlock mounts, I too had screw thread mounts. You know when they would come off? When you were machining along a back inside edge or something when you were running in reverse, whether you wanted it to or not. For this reason alone, the camlock would be a huge blessing. There are others as well, but I digress...Again

Now I make a lot of things out of recycled axle shafts, as many of you know, and I got to thinking. What if you took an axle flange, with a short shaft for chucking, annealed it, and knocked the studs out of it. This would be mounted in the chuck, rotated backwards and cut around the outer edge with a good-big general purpose HSS tool (5/8 or so) mounted upside down in the toolholder?

If the chuck didn't came loose during the regular turning, when it began the interrupted cut over the stud holes, I'll bet the hammering would be just the thing. Put a board over the ways for protection, and save the axle part and the tool bit for just this purpose.

Hope this suggestion helps, as it avoids abusing the back gears, or risking injury from applying a lever or strap to an operating machine or any of a number of other effective but unsafe techniques

Bill Walck

[Mr Ron]

My old Sheldon 11" lathe is in near perfect condition after 60 years. It really hasn't seen much use or abuse. I want to keep it that way. I'm confident this machine will hold it's own against any machine made in China or Taiwan.

[Rich_Carlstedt]

You are correct about broken back gear teeth. Seen lots of home shop lathes that way.
The teeth break because of sudden impact.
I cringe when i hear about using a torch or other heat.
My recommendation which has been used successfully many, many times is as follows.

Get a 2 x 4 about 18-24 inches long
Get a mallet ( leather or dead blow preferred )
Open the jaws so the 2 x 4 can fit between the 3 jaws
Insert the 2 x 4 inside the jaws and have it at the 2 o'clock position ( viewed from the tailstock )
grab the 2x4 about 6 inches from the end and pull smartly towards you ( CCW )
When the 2 x 4 is almost level , smack it with the mallet...make sure you don;t hit your hand !
Very important that you do this with the pulling of the chuck as that keeps all play out of the back gear
and that way they cannot snap, and yet provide drag for the spindle.
Make sure you hold onto the board, else it will fly out of the chuck, hitting the lathe bed and bouncing into your face,
Watch that you don't drive your hand into the ways when the chuck comes loose
Rich

[Bill_Cook]

The 8"chuck on my not so nice 11" Sheldon weighs a lot more than the spindle. I snapped it tight enough that it won't come off in reverse. It is a belt drive spindle. A 2 1/4-8 thread can take a lot more than that.

The lathe came with a tooth missing on the large diameter gear on the back gear shaft. That cost me close to $200 around 1990.

The plan, if the chuck ever has to come off, is to make a spanner that will hook the bottom of a jaw groove. The hook and heal will be covered with phenolic or aluminum. To hold the spindle a wrench will go halfway around the spindle and push against the pin that gets pulled out to use the back gear.

I may mill a couple notches in the back plate 180° apart while it's off, but I'd rather not create an extra spinning hazard.

Whatever needs to be used to hold a part has been able to be held in the chuck. Before I got the chuck I did use the face plate with 3 buttons, a ring, and 3 threaded rods to make a bowling ball planter.

Also a 2 step "V" pulley was made by bolting the stock to it. Either of the two could have been done with the chuck on.

[mcostello]

I had to cut off the top of a bowling ball for a friends kids art project. I opened up an 8" chuck about 1/2 way,pushed against the end with a live center with a large washer, and held it from turning with a lot of duck tape. Worked to part off a lid.

[rudd]

For getting stuck chucks off without damaging the back gears, there is a simple, elegant solution. Backplates are cheaper and easier to get than gears.

https://tinyurl.com/nt69e74

[Mr Ron]

I came up with a thought. Chuck a 1/2" extension in the chuck and use an impact wrench in the extension to loosen the chuck. I haven't tried it, but I think it might work.

[tornitore45]

rudd the link you posted is misleading and not appreciated. It point to an item on ebay that has nothing to do with the subject