1541 Alignment disk

I did say 'non trivial', not 'impossible' :-). This is not the sort of thing yuo coudl do with hand tools iMHO. Given that you want the cavity in he psindle to remain circular, I would think borign it out on a lathe is the obvious way to go. Settign ti up in the 4-jaw with a DTI would be entirley possible. But there is als othe issume that you want the disk to remain pproperly centred, so you can't make the cavity too large or the centring cone will not correclty laign the edges of the hole in the disk. I am actually not sure you ahve enough tolerance to recut the spindle to be eccentric and keep the disk correctly aligned. You make have to make a complete new spindle, dilbieratly offset. Agian possible give na lathe, but not totally trivial. -tony