[dingo0722]

We need to align our programable tow along tailstock on our Crown turning center. I have loosened the 4 hex bolts in the corners and got the center aligned with in .0004, but the elevation is off by 0.006. How do I adust for this?

[OkumaWiz]

Normally they sit high by about .003" to compensate for heavy parts between centers and to allow for wear over the years which actually may make it improve. They are hand scraped in at the factory this way and in most cases if it is off, your machine is not leveled correctly and has bow in the center.

I'd get a good precision machinist level and start there. Move the machine to the left and right and see if the level is changing depending on the turret location. Also when re-tightening the bolts on the tailstock be sure to tighten evenly to avoid distortion. (much like head bolts on an engine or lug nuts on a wheel)

This should get you closer to the factory spec.

Best regards,

[kawarta]

on the operation and maintenace manual is the procedure to align the Tailstock, turret and headstock.
good look

[underthetire]

And always start by checking the headstock first.

[dingo0722]

So I checked the head stock and over 4 inch I am getting 0.0003" of taper, big end Z+. I used 1.375 Al, so I might be getting a little deflection at the end. After I confirmed the head stock was reasonably square I aligned the tailstock using a coaxial indicator. I tried using a mag base indicator and was beating my head as I could get the tailstock within 0.0002 in the horizontal but it was sitting 0.008 high in the vertical. Turns out a the indicator was experiencing droop. Once I ditched that and went with a coaxial the vertical was perfect at 0.002" high and the horizontal was not measurable.

thanks