This post was copied from the Antique machines forum on http://www.practicalmachinist.com where I am getting a lot of help from some very knowledgeable guys

Well I went back and did some more measurements, tests, etc. and convinced myself that the spindle wasn't bent. I DTI'd the inside of the spindle and discovered a lump which I previously hadn't noticed when I cleaned it up. Took some removing but eventually it was gone. Retried the taper and the runout was now a much more reasonable 0.04mm (2 thou) average (rotating the taper in the spindle), max .06mm, min 0.02mm. DTI'd the inside of the spindle and got .03mm (1.2thou) runout.

So then went back to the issue of the eccentric cut. Set it all up again, tried bar test for bearing movement and put more effort into it and was getting .2mm (8 thou) movement lifting vertically, but .4mm (16 thou) pressing down. I also discovered 0.4mm end play on the cross-slide (at certain positions of the handle you can physically move the slide - with a clunk!) that will have to be dealt with as well but still felt the problem was in the bearing.

Decided to take the plunge and get the shaft out. In the end it came out surprisingly easily... here are some pics of what I found...




can you see whats wrong yet :roll: