Setting up lathe speed with 7i76 digital pot

What are the values of:
hm2_5i25.0.7i76.0.0.spinena and hm2_5i25.0.7i76.0.0.spinout
when you have requested full spindle speed?

I changed the settings for .spinena back to how they were.

As long as spindle is On, .spinena is true.

I tried both in low and high gear (in PP) and the results are
Low: .spinout equals set RPM
High: Obviously my scale is not set correct, as my results are
RPM .spinout
200 145.3488
1000 726.7442
1800 1308.14

No change in actual RPM of the spindle in any of these tests.

Stig

If you only have 2.2V across the 7I76's digital potentiometer you wont get any output voltage. I suspect you will have to supply an external 10 or 12V power source for this to work since it appears that the motor controller cannot supply the couple mA that the 7I76's digital potentiometer requires. Beware that the potentiometer wiring on many low cost speed controls is _HOT_ = at line voltage potential so any external power supply
must be isolated (something like a wall wart may work)

So connect negative of the external psu to both speed controller (bottom of pot) and spindle- and positive to spindle+ ?

_Maybe_

Do you have any documentation on the drive?
Are you sure potentiometer+ from the drive is DC? (relative to potentiometer-)

The 7I76 (voltage output) potentiometer replacement is meant for DC voltage controlled drives,
not all inexpensive SCR drives work this way however

No, but it is the same clone of a KBMM-225 (or something like that) as used on most of these Chinese benchtop mills and lathes.

I measured 5.5v DC across the original potmeter, so I'm fairly certain it is DC controlled. I can test if there are any AC there as well.