[How-To] Running a threaded spindle in reverse?

[woodchucker]

I just acquired my first lathe (SouthBend heavy 10L) that has a threaded spindle to attach the chuck and other equipment. I have heard never to try using this lathe in reverse as this will unthread the chuck. Is there a safe way to use this machine in reverse?

I drilled my chucks and spindle. In the spindle I have a drilled hole for a dog point set screw. I used to have a brass set screw, but this is more positive. I still need to take light cuts. On my Bison there was not a lot of room for the screw, so it's small... don't remember, maybe a 10-32. I put the dogpoint on the set screw. you don't need a dogpoint, only for the screw to seat down, I didn't want to have a problem with the screw when I want to back it out.

 

[WobblyHand]

Doesn't this limit the length of stock you can put in your chuck, or am I misunderstanding (most likely!) what you've made here?

Yes it does. But it is still useful. Larger stock has more potential to unwind the threads, and that stock wouldn't fit through the spindle.

 

[mickri]

You can't put anything through the spindle. I lose about 1/8" of depth on the ID of the bore of the chuck.

 

[durableoreo]

My lathe has a threaded spindle. The original dual contract arrangement. Anyway there's a groove in the spindle. If you fit your backing plate with a threaded hole, you can secure it.

 

[woodchucker]

correction. I noticed I did not use the dog point. I probably realized it was too small, it looks like I used the screw full size.

 

[Jimsehr]

You can't put anything through the spindle. I lose about 1/8" of depth on the ID of the bore of the chuck.

 

[woodchucker]

You can't put anything through the spindle. I lose about 1/8" of depth on the ID of the bore of the chuck.

yea, that's not making sense to me? Obviously Jim either.. whatcha mean... a little clarification.
never mind. I searched back and found out what you were talking about.