Thanks for pointing me to this thread. Here is a curve showing the linearity we get out of the C32:
As you can see the curve is a little higher than it is supposed to on the lower end (usually when accuracy counts more). I think this circuit may be improved. I will take a second look at it.
In your case, you think you may be just fine by moving the curve just a little bit down. You can do that by lowering the max speed or y playing with the on-board potentiometer.
Other solutions could be:
- Closed Loop Spindle: This used to work in Mach3, but the latest I know it is not working on the current versions of Mach3. It is not currently supported on the PoKeys or ESS, but I am sure it will get implemented soon. You can also implement it on the pokeys using brain, macro or LUA script by writing a script that would do the PID to correct the PWM to reach the commanded spindle speed.
- Another solution would be to implement spindle speed control via Modbus.