Can't get lathe to Feed

A CNC lathe without threading is a very limited lathe, though.

You are making me feel bad

If you can find even one pin for a single pulse per rev (drive A and Z from one pin), then you can get threading working without much effort.
2 pins would be better (separate A and Z) though.

Theoretically you could get 2 PPR with 1 A+Z pin (and a 1/2 disk encoder wheel)
if the encoder component could be taught to count rising and falling edges of A

PCW wrote: Theoretically you could get 2 PPR with 1 A+Z pin (and a 1/2 disk encoder wheel)
if the encoder component could be taught to count rising and falling edges of A

To stray off the subject of this thread, we could also look at doing what the car industry do, and using a missing-pulse for index.

There are even systems that give position, index and direction on a single line, by changing the duty cycle of the square wave to indicate direction.

There are also some of the magnetic encoders that use PWM for absolute 1 turn data