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Help please - new lathe spindle wobble

S

Steve Appling

Joined
Sep 14, 2025
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Location
Acworth, GA
I would appreciate some help. I'm a complete newbie. I took a class, got the turning bug, and began looking for a good deal on a lathe. I bought my first lathe, a Jet 1221vs on Facebook marketplace and thought I got a great deal. I may have figured out why.

When attempting to turn my first spindle piece, I rounded it, cut a tenon, and put it in a chuck. It really seemed to wobble. After more investigation, I see the chuck is at a slight angle. I placed the tool rest very close and parallel to the side of the chuck. As I rotate the chuck, I see the angle of the chuck change :(

Now that I have it home and look more carefully, I also see that the threads on the spindle are messed up. I understand from the post here, that it is normal for the first couple of threads on the Jet spindle to be flattened like this, but I'm not clear if these threads are right. I can't actually thread either of the chucks I have completely onto the spindle.

I'm guessing that:
  1. The threads might be messed up
  2. The spindle is warped in some way
  3. The bearings are messed up
Any thoughts? Should I just get a replacement spindle and bearings?
 

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I'm somewhat of a newbie as well so take what I say with a grain of salt.

It looks in the first two pics that the chuck is not screwed all the way onto the spindle?

If it were mine I would take a file and try to clean up the threads and try to get the chuck all the way on. That will straighten it hopefully.

Maybe the spindle needs replacing? But at this point what do you have to lose?

Ya, what he said, he beat me to it.
 
Obviously the thread crests have been trashed (likely by a set screw someone forgot to revove). In your third picture, the third thread from the end is deformed on the right side and is likely what is preventing the chuck from seating against the spindle shoulder. Clean it up with a triangle file and get the chuck to seat against the shoulder and it will likley run much better.

Tim
 
I have had 2 experiences similar to yours. Due to a monster catch I had when beginning to turn, the spindle on my Jet 1014 got bent and had to be replaced. This was a surprisingly simple procedure for someone with no experience. The new spindle was tolerably pricey.

When I bought a used Powermatic 3520, the chuck wouldn't screw all the way on. With the help of the folks on this forum, I cleaned up the threads with a triangular file and fixed the problem. Also surprisingly simple, if you are careful.

Maybe it's the camera angle, but your third photo looks to my eye like the threaded portion of the spindle is at an angle from the shoulder. If this is the case, the spindle is toast and you can learn for yourself how easy it is to replace.
 
Well, not sure, but those threads may be able to be fixed by a machine shop. One thread in particular looks VERY bad. The chuck has to seat against the headstock, and must be flush. It may just take a bit of filing with a triangle file or saw sharpening file. Don't really know.

robo hippy
 
Sounds like you need a new spindle. It may be worth replacing the bearing while you're at it. I would search the numbers on the bearings, because it is probably standard size and you won't need oem.
 
I had a lathe that came with a steel spacer to be used if a chuck or faceplate was not seated solidly against the spindle shoulder. (longer spindle than usual)
I believe you could use this to get your chuck to seat properly, easier and less costly than going to a machine shop.
Also the thread on the spindle can be repaired with a file ( there are thread files to do just this )
 

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No reason to replace, or even remove the spindle. Those threads can be filed to work just fine, just take it slow with the filing, and use a file of appropriate size. Spindles are soft steel and easy to file (I have experience unfortunately). There will be plenty of thread engagement to hold chucks etc on the spindle safely.

As others noted the chuck must seat against the shoulder. The only time a spacer should be used on the spindle shoulder is if the spindle is too long and bottoms out in the threaded hole, and in such a case the interference should be addressed on the accessory item if possible vs using a spacer.
 
This spindle is goofed up enough that filing the threads may be a futile exercise, unless the original poster is experienced in this. If he was experienced, he wouldn't have made the posting. I think it's a bit to far gone to try filing also, as the threads are sufficiently buggered as to keep the file tracking true difficult. I'd try a rethreading die first. The threads at the very nose are still pretty good, and a rethreading die would get established on those before getting to the damaged area.

Here is one of many examples available online: https://www.amazon.com/CARBON-STEEL...&sprefix=1+x+8+rethreading+die,aps,138&sr=8-6

Rethreading dies are hexagonal instead of round, so that you can use a big crescent wrench on them. If you go page three of this document: https://www.turnrobust.com/lathe-maintenence/ I discuss using a file or a die to clean up spindle threads. If all else fails, a replacement spindle is in order. Yes, do the bearings while you're at it.
 
Steve Appling said:
I would appreciate some help. I'm a complete newbie. I took a class, got the turning bug, and began looking for a good deal on a lathe. I bought my first lathe, a Jet 1221vs on Facebook marketplace and thought I got a great deal. I may have figured out why.

When attempting to turn my first spindle piece, I rounded it, cut a tenon, and put it in a chuck. It really seemed to wobble. After more investigation, I see the chuck is at a slight angle. I placed the tool rest very close and parallel to the side of the chuck. As I rotate the chuck, I see the angle of the chuck change :(

Now that I have it home and look more carefully, I also see that the threads on the spindle are messed up. I understand from the post here, that it is normal for the first couple of threads on the Jet spindle to be flattened like this, but I'm not clear if these threads are right. I can't actually thread either of the chucks I have completely onto the spindle.

I'm guessing that:
  1. The threads might be messed up
  2. The spindle is warped in some way
  3. The bearings are messed up
Any thoughts? Should I just get a replacement spindle and bearings?
Click to expand...
When I first started turning I made the set screw error and wrecked the threads on my Jet 1221, Bought a replacement spindle and swapped it out. Still running true 10 years later
 
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