Rear spindle issue

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

Moderators: Harold_V, GlennW

Post Reply
sbordona1
Posts: 1
Joined: Tue Feb 20, 2018 8:06 pm

Rear spindle issue

Post by sbordona1 » Tue Feb 20, 2018 9:09 pm

I have a 7x12 mini metal lathe (Harbor Freight) and would like to add a rear spider tool. Presently there isn't enough room because there are two threaded nuts. If I can remove the most outer nut I would have enough room, but I don't know how to remove the most outer nut, can anyone help, thanks in advance for your input.

spro
Posts: 6998
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Rear spindle issue

Post by spro » Wed Feb 21, 2018 1:53 am

I can only suggest for I don't own that lathe. The inner nut is likely for preload of the spindle bearings and the outer nut, to lock it. Before trying anything, mark carefully the position of the inner nut to the spindle. It may need adjustment in the future but not now. Things can happen as you unwind the outer nut by two wrenches as the inner may try to compress the bearings. By all means look at the outer nut for some locking device and unlock it. If the chuck or back plate is tight, you can attach a bar across two holes and resting at the back of the bed. The outer nut should unscrew before the chuck would. You are still holding the wrench for the inner nut but allowing it to swing with your marks, NO tighter to the bearings.
The spider cap may be replacing the outer nut and there has to be a way to reliably secure it and allow for preload adjustments.

spro
Posts: 6998
Joined: Mon Feb 20, 2006 11:04 pm
Location: mid atlantic

Re: Rear spindle issue

Post by spro » Wed Feb 21, 2018 2:20 am

Oh. Welcome to the Site and forum ! You will receive better advise. This is only starters.

RMinMN
Posts: 30
Joined: Tue Jan 02, 2018 8:50 am

Re: Rear spindle issue

Post by RMinMN » Wed Feb 21, 2018 8:19 am

That does appear to be the nuts for preloading the bearing and locking. My mini lathe has about 3 threads beyond the lock nut. It might be possible to fit a spider onto those threads as there shouldn't be a significant load being carried by the spider. My manual shows the nut as a 27x1.5 so that has to be the thread to work with.

User avatar
tornitore45
Posts: 1499
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: Rear spindle issue

Post by tornitore45 » Wed Feb 21, 2018 8:39 am

Sometimes the best solution is a different one. You mentioned a spider which leads me to guess you want to place a centering device to keep thin stock protruding from the spindle to flap around dangerously.

A plug, with a suitable hole, with an O ring to friction keep it like GlenW posted
or as simple as a cork can achieve the same results.
Mauro Gaetano
in Austin TX

Post Reply