+-10 volt spindle?

Actually quite a few people use the Mesa analog outputs for tachometer simulation.
It works fine especially since the encoder velocity signal uses timestamping for better velocity estimation than Counts/DeltaTime

JR1050, Do you have any recommendations for a good drive for these servos that wont break the bank?

Ive used AMC amps before,they are easy to set up and can be found cheap as pull outs. The smaller ones are not real expensive new. If your Fanuc drives work, keep them, they are bullet proof. Changing the drives will allow you to run in current mode with out tachs, but I have found current mode drives more difficult to tune. The black cap motors used scr drives and the yellow cap transistorized. Your lathe probably had a 5T, 6T or 3T ?

It was a 5t. I got it going again with the old control but reliability was a joke. Also programming it was too much fun.

I know about 5t. I had an Ikegai with one and my Mori has one. Not fun to program at the control.... With a btr and getting used to no.decimal point, not really that bad.....

Yeah that was the problem. the BTR in it would not work. I wrote a simple program from the control and that was enough to tell me it was time to fix that problem.