Spindle or Chuck runout on LeBlond Regal

Hello All,

I actually don't know I have a good enough dial for this work as mine is only 0.001 per/div. Using that I get about 0.001 at the face of the spindle where the rear of the backplate would register and 0.003 on the diameter of the spindle just forward of the vertical face BEFORE the threads start.

I also measured the ID of the rear of the backplate where it would register against that shoulder of the spindle and it is 0.010 larger than the same location on the spindle.

Moving to the right the first step (photo "A") on the exterior of the back plate shows 0.003 runout and the second step (photo "B"), or the one that is supposed to match the diameter of the rear OD of the chuck, is measuring 0.013 runout.

See the pics.





I just ordered a complete set of 1-3/8" x 8TPI Plug & Ring "GO / NOGO" gages and now looking for ductile iron rod or discs to turn into my own backplates. At least this sets me up for any work I may need to create for this spindle size. I really enjoy this little lathe so far and it will be here for the foreseeable future. Might as well be as equipped as is reasonable.

Any of your thoughts moving forward from here would be greatly appreciated. I have no idea as to how much work this lathe has done or how often the chucks moved on or off, but there is a 0.025 taper on the threads of the spindle. My plan was to first start by VERY carefully facing the spindle to register with the rear face of the backing plate while waiting for the ductile iron to arrive.

Once the new iron arrives I will chuck her up with the 4-jaw, drill, and cut the threads to match the existing taper of the worn spindle threads. Then install the new backplate on the spindle, turn the two diameters, face it off and create the concentricity registration shoulder for an interference fit with the rear of the chuck.

Am I going down the correct path with the proper order of things or have I missed something a more experienced eye would see?

Cheers,

David

I'm not sure why your putting an indicator on the backing plate and I'm even more unsure of what your trying to do.
How does round stock look when spinning the chuck? Taper on the spindle nose thread? I'm not familiar with them but it might just be a lead in to screw the chuck on easier. I would imaging there a land area where the chuck registers to the spindle, but again I don't really know. Maybe some else with more knowledge will chime in and help you. Sounds like your over thinking things.

Haney

Before you go charging on correcting things, have you made sure the spindle registers are running true (they will be unless someone screwed up bad.) Where are you chasing runout? It doesn't really matter that you have runout on the non critical OD's of a backing plate, who cares so long as the face runs true.