Turret Alignment Yang ML60A?

We had a pretty bad crash on a Yang ML60A lathe. I was able to align the axis of the turret parallel with the axis of the spindle, but I can't seem to figure out how to adjust the tool position of the turret to its alignment with the spindle. I loosened the outer row of screws (smaller size SHCS) that go thru the turret assembly and mate to the curvic coupling, but the turret will not rotate?

I decide to remove the turret to have a look at what I am dealing with.........beside finding a lot of rust and corrosion, the turret side of the curvic coupling is dowel pinned to the turret? How does this allow for any adjustment for alignment?

What am I missing?

Any help would be greatly appreciated.

Thanks, Dave

hotrod1442 said:

the turret side of the curvic coupling is dowel pinned to the turret? How does this allow for any adjustment for alignment?

Click to expand...

G'day Dave.

Welcome to the forum.

You will probably find that the dowel pins are dog leg bent. It happens all the time, the bolts might slip in the holes because there is clearance, but the dowels will bend or bell mouth the holes. Good chance they are tapered dowels, and being Yang will probably be metric 1:50 taper.

You have to remove them to get your alignment back. You will also find a set in the curvic half that is bolted to the turret body. They could have moved also.

Opinions on the dowels are wide and varied. You can leave them out, or re-ream and put new ones back in.

On some couplings, you can find a master set of spare dowel holes. They wont have dowels in them. But you can use them to get back to factory alignment. I don't know if you will find that feature on a Yang. I've seen it in Okuma's.

Regards Phil.