Karl Townsend wrote:

I need to control a pot with my CNC control. One option is to get a pot
turner like this:
http://www.cnc4pc.com/Store/osc/prod...roducts_id=179

This would work but I'm not real keen on having a device to physically turn
a knob.

I've got a whacky idea that I'd like to run past the EE types in the group.
I have a large number of unused Opto 22 digital outputs
http://www.opto22.com/site/pr_detail...=4&item=G4ODC5

For sake of argument, lets keep the numbers simple. Get four resistors, 100,
200, 400, 800 ohm in series in place of the pot. In parallel with each
resistor put an opto output. Then using base two, any resistance from 0 to
1500 ohms is possible. The switch time on these outs is 100 microseconds -
I'm thinking a pot to control power level on the plasma cutter couldn't
possibly notice the switch time. I don't know if these devices will work at
0 volt between the otpo 22 output connections.

Or is there another easy way to do a pot with a CNC control?

Karl

What is the point of this "pot turner"? You seem to imply that you're
trying to control the cut current of a plasma cutter from the CNC, and
per the folks who make the plasma cutters, including the hi-def ones,
controlling the current during CNC cutting provides little to no
benefit.