I am an idiot - stuck chuck - again

M

Makintrax73

H-M Supporter - Silver Member
H-M Supporter - Silver Member
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Jun 20, 2022
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I've had my lathe for almost a year. Apparently I don't learn. I did a very light boring job in AL on a face plate tonight. When I went to clean the machine the faceplate was hopelessly stuck. :frown:

This is not the first....or second....or third time I've stuck my chuck. Each time it has been from failure to inspect the threads for swarf and there being a few very tiny pieces (AL I think) in the threads.

The last time this happened I made a tool. A rod with left hand threads on one end that goes through the spindle. Except that didn't work. The rod kept spinning in the spindle bore despite being REALLY tight. So I got out the torch. Heated the faceplate pretty damn hot. And I got out a 1lb ball peen hammer, and bolted a nice chunk of steel to the faceplate to pound on. The shock of whacking it did the job (eventually) despite the rod wanting to rotate. I was starting to envision cutting the faceplate off the lathe and wondering how I'd do that without screwing the spindle up.

My lathe and everything else appear to have survived unscathed. But since I'm too dumb to remember my penance is admitting I'm stupid for not cleaning the
%$%ing threads every time I change out the chuck. Hopefully this reminder will help one of you to not be as stupid as I am. Clean and oil your spindle and chuck threads before you install it.

I wonder if anyone makes 3D printed chuck thread inserts to keep swarf out while they are sitting around? Or maybe I should buy a nice 1 1/2" piece of delrin and make one.
 
If nothing else, a tiny chip can cause my backplate to not seat properly. After screwing with my chuck and making my own backplate from scratch chasing the holy grail of damn near zero run out, I appreciate every little step to help improve that. If I could cause my chuck to not wanna come off, there would be no way I wouldn't clean the hell out of my spindle threads. Hopefully 3 is the charm for you!
 
Like this?

www.thingiverse.com

Lathe Chuck Wall Mount 1" 8TPI by agenkin

I designed a simple 3D-printed mount that allows me to store my wood lathe chucks on the wall or any other vertical surface. I mounted mine on the wall of my wooden lathe stand. The mount is designed for 1″ 8TPI thread, but if you like the idea, it should be very easy to design the same mount...
www.thingiverse.com www.thingiverse.com

There are a few others depending on the size you need.
 
Last edited:
Inferno said:
Like this?

www.thingiverse.com

Lathe Chuck Wall Mount 1" 8TPI by agenkin

I designed a simple 3D-printed mount that allows me to store my wood lathe chucks on the wall or any other vertical surface. I mounted mine on the wall of my wooden lathe stand. The mount is designed for 1″ 8TPI thread, but if you like the idea, it should be very easy to design the same mount...
www.thingiverse.com www.thingiverse.com

There are a few others depending on the size you need.
Click to expand...

Mine is 1 1/2"-8, but yeah that's exactly what I had in mind. Swarf can't really get in there when it's installed on the lathe so I think this would keep them clean when sitting.
 
I don't know how you locked your spindle, but I can tell you that what you are doing can break teeth on the bull gear or back gear if you are locking it that way. I don't know what type of lathe you have either, it makes a difference in the various solutions. I have had a few nasty lock ups. I now take a wooden wedge and lock my bull gear that way. it doesn't hurt it, I won't lose teeth that way. For some lathes there are 3d prints sold on ebay to lock the bull gear up. Would love to get one, but I can think of many other ways to spend my money. Also for the chucks : for 3 jaw, I lock a 6 sided piece in it and wrench on the piece rather than risking cracking the chuck by using a jaw. 3 jaws have more locking power than 1.
For a 4 jaw chuck I mount a square in and wrench on the square.
 
As noobie 1½-8 threaded spindle guy, I really appreciate reading all this.

Besides keeping both threads clean, do most folks just use way oil or something to avoid this?
 
woodchucker said:
I don't know how you locked your spindle, but I can tell you that what you are doing can break teeth on the bull gear or back gear if you are locking it that way. I don't know what type of lathe you have either, it makes a difference in the various solutions. I have had a few nasty lock ups. I now take a wooden wedge and lock my bull gear that way. it doesn't hurt it, I won't lose teeth that way. For some lathes there are 3d prints sold on ebay to lock the bull gear up. Would love to get one, but I can think of many other ways to spend my money. Also for the chucks : for 3 jaw, I lock a 6 sided piece in it and wrench on the piece rather than risking cracking the chuck by using a jaw. 3 jaws have more locking power than 1.
For a 4 jaw chuck I mount a square in and wrench on the square.
Click to expand...

As I stated in the OP: I had previously made a left hand threaded rod. It goes through the spindle. Nothing whatsoever touches the gears. The left hand nut on the back of spindle gets a 3/4 socket and breaker bar braced against the bench. Because it is a left hand nut when you (attempt to) loosen the chuck it can only make the nut on the back of the spindle tighter.


@OCJohn I use light machine oil on my spindle threads. I believe that's what the manual calls for, but certainly any oil is better than none. In my case I believe there was plenty of residual oil, and there is certainly no corrosion at all. For some reason I think when I get bits of AL in the threads they lock in when you cut with the machine.
 
The last time this happened I made a tool. A rod with left hand threads on one end that goes through the spindle. Except that didn't work. The rod kept spinning in the spindle bore despite being REALLY tight. So I got out the torch. Heated the faceplate pretty damn hot. And I got out a 1lb ball peen hammer, and bolted a nice chunk of steel to the faceplate to pound on. The shock of whacking it did the job (eventually) despite the rod wanting to rotate. I was starting to envision cutting the faceplate off the lathe and wondering how I'd do that without screwing the spindle up.
Click to expand...
well you said it didn't work the rod kept spinning, so how did you lock it up this time?
 
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