One question that's been nagging me - I'm using a lot of speculation from a position of relative ignorance so please bear with me!

- On a lathe, the absolute position of the spindle (and I mean absolute in the sense of knowing e.g. where a specific chuck jaw is from one work session is to the next) isn't important. What's important is knowing where the spindle is relative to the first cut that was made on a specific workpiece.

- If the above is correct, then the only need for a Z (index) output on the spindle encoder is for pulse-count verification.

- If both the above are correct, then there is no reason you couldn't increase the effective pulse count of the encoder by having a different drive ratio to the encoder e.g. having a 1:4 drive would increase a 2000p/r encoder to be 8000p/r of the spindle.

Does this make sense, or am I missing something? I guess you could run into non-linearity problems if one of the pulleys was too small and the belt had any 'set' in it.