Leblond Regal 15" Cross Slide Leadscrew Help

[mikeyjones]

Hey guys -

I'm working on a Leblond 15" Regal lathe and want to remove the 90thou backlash in the cross slide leadscrew. So I set out to replace the screw, however I'm running into a bit of a wall and wanted to get advice here.

I ordered this: McMaster-Carr to replace the screw part and a 2.5" drop of brass to make a new nut.

The issue that I'm running into is I can't get the spline off the old screw. I knocked out the pin, but the spline won't budge. Any advice?

Thinking maybe to cut the old screw right past where the pin sat, bore out a bit of a hole, turn down the new screw for an interference fit, then just drive a pin to hold it together. I'm just worried about concentricity, but not sure how much it really matters in this application if I'm off by even 5 thou.

As an aside, anyone on here want to make the nut for me? I can't seem to find my 4 jaw chuck.

 

[Richard King]

On page 37 it looks like there is a Woodruff key (567) that could be holding it. http://vintagemachinery.org/pubs/2102/20006.pdf

 

[ClappedOutBport]

What are the threads on the nut? Got a tap?

 

[James H Clark]

Mikey: Have you thought about just re-cutting the screw and making a new nut to fit? If the rest of the screw such as splines and other diameters is OK, just recut the screw.

JH

 

[moonlight machine]

Hey guys -

I'm working on a Leblond 15" Regal lathe and want to remove the 90thou backlash in the cross slide leadscrew. So I set out to replace the screw, however I'm running into a bit of a wall and wanted to get advice here.

I ordered this: McMaster-Carr to replace the screw part and a 2.5" drop of brass to make a new nut.

The issue that I'm running into is I can't get the spline off the old screw. I knocked out the pin, but the spline won't budge. Any advice?

Thinking maybe to cut the old screw right past where the pin sat, bore out a bit of a hole, turn down the new screw for an interference fit, then just drive a pin to hold it together. I'm just worried about concentricity, but not sure how much it really matters in this application if I'm off by even 5 thou.

As an aside, anyone on here want to make the nut for me? I can't seem to find my 4 jaw chuck.

Order new proper lead screw material and threaded oversize material for the nut from Green Bay Mfg. They have many thread pitches so your dial will be accurate and have the lead screws and nuts in left and right hand threads. The nuts are available in bronze and iron. Green Bay Mfg. has an amazing amount of lead screw and nut options.