Hi Ron,
Bruce found the taper of the ball/cone made it difficult to chuck them securely in the lathe especially so that they'd run true the full length. Consequently the morse taper drill he was finishing with snagged when in deep and twisted off part of the drill thus stuffing it. Maybe boring a taper or step-boring into a length of round or square bar stock and tacking the ball into it might help but one is trying not to tool up for mass production where it can be avoided
He is looking into making new shafts but hasn't decided yet.
Jack, appreciate your experiences. I think by compressing the springs Bruce managed to cut the shaft without damaging the springs (or is that one of the things you also did) but I'll get him to verify that to me and let you know.
Regards
Alex