# Repairing the tail stock on a 10L



## Pacer (Sep 8, 2011)

As with the rest of my SB 10L, the tail stock was worn pretty badly. In this post I'll describe how I refurbished the acme threaded spindle screw and the threads in the spindle, then I had to address the slop in the spindles hole through the TS casting. Also the TS locking plate had to be replaced --- whew!!

McMaster Carr offers Acme thread stock suitable for lead screw applications, and also have matching threaded brass nuts. The thread stock comes in most any thread pitch and length, I went ahead and bought a 3" 1/2-10 left hand stick, was only a couple $ more than a 12" (about $10) The brass nut is a bit more pricey, at around $32.

I stubbed the worn threads off and turned the 1 1/4" stub down to 3/16", then taking a piece of the screw stock and reaming a 3/16" hole in it for inserting into the stub of the handle shaft with a bit of loctite.

Chucking the spindle up and turning very true (you want the thread dead center) I bored out the old threads to about 1" depth to 11/16" for the 3/4-16 tap. Then setting up the brass nut in the lathe - again, dead true - and cut it down to thread the outside to the 3/4-16 - I then screw &amp; seat the nut into the spindle with loctite.




Then I had to address the spindles slop where the guide pin rode in the slot that keeps the spindle from rotating. I first had to get the pin out?? Had to do a bit of head scratching on that... Taking a close look - for about the 3-4th time - I finally spotted a faint round outline under nose of the housing. Was so blended in that I at first thought SB had filled it in with babbitt, but a light touch with a drill bit showed no babbit and that the pin wasnt hardened. Was obvuous that it was in at angle (turned out to be 45Â°) so got a punch and it pretty easily was driven out, and appeared to be something like common drill rod measuring at 5/16" (SB loved 5/16 stuff, theyre all over the lathe!). Found a short piece of 5/16"drill rod, set it up in the vice at 45Â° and milled a 3/16" tip on it. On tapping it back in the housing and trying the spindle, it would only bind up - after fiddling with it a bit, I pretty quickly decided that the slot on the spindle had to recut in a straight line --- set it up in the mill and cut a 7/32" slot down the length of the spindle (and through the new brass nut), Then milled a matching 7/32" tip on the pin, put it back in, and --- whoa!! what a difference. really smooth action and almost no slop. Very satisfying results...










Heres a shot of the "before and after" on the slide locking plate --- that was a first class brazing job .... NOT!!


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## Davo J (Sep 13, 2011)

I must have missed this in the forum rearranging and only found it by a link from HSM.
You have done a great job on that, well done.  ;0 would be like using a new tailstock now.

Dave


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