Hello,
Not sure what happened with settings here, I got a notification regarding the first reply, but nothing after.

Thanks John, I will read through.


Brian,
Steppers: I went for nema 34 only because the original steppers have the 34 frame. Without much guidance, I was trying to limit the number of modifications to a minimum.
But very soon, I ran into a "problem" : the belt profile is 100XL037, the original pulley has 12 teeth, and the new motor has a 14mm shaft. Can't find a pulley with such a spec.
I ordered one 12T XL profile, but I have to open the bore and cut a key. I could have bought a nema 23 but only recently I found an adaptor frame 23 to 34.
After your post, I ordered DM860H drivers and a 60VDC source to use the original motors. I will play with the 34 closed loop once more knowledgeable.
Do you have an wiring diagram for the motors/wire color combination? I found a discussion about parallel and serial connection. I am planning to use the original wire combination.

The encoder on my lathe is a 5V (four wires : SYN, +5V, SPD, GRN). I been advised by the P-CNC tech support to buy opto isolators for all inputs and outputs. There were some questions around the encoder being PNP or NPN that I could not answer. I will updated with the progress once my 5V source will arrive.

VFD - If easier/ safer , I will buy a new one. No point of taking the risk of grilling the board. Any recommendations for a decent modern one? What should I look for? 1 phase to three? 750whats?

thanks,
a