[cmanning]

I'm in the middle of trying to setup a Sherline variable speed motor to be controlled by my G540. I'm looking at the control board for the motor, and there is a Max, Min and Accel attached to the potentiometer. Does anyone have any idea which of those relates to the VFD GND, VFD OUT and VFD +10V that the G540 uses to control the speed? With all of the warnings about not hooking it up wrong, I really would like to get this right the first time around.

Thanks
Chris

[Jeff-Birt]

Depending on the type of speed control it is you may not be able to run it in voltage following mode. Is there any manufacturers info on the board?

[cmanning]

Jeff,

The motor does accept voltage to control speed (Homann Designs has a board that does exactly that for this motor.) I haven't found anything from Sherline on this motor yet, and I'm waiting for a reply from them.

Thanks
Chris

[Jeff-Birt]

I think you are mixing up two different things. The motor speed control takes 115VAC and gives you the 90VDC needed for the motor. The pot you turn controls how that 90VDC is 'chopped up' to allow the motor to spin at different speeds.

Some motor speed control boards will take an external 0-10V signal in place of the pot. This allows you to vary the speed automatically, but you need a way to generate the 0-10V signal. (Some will also take a PWM signal.)

There are several places that sell small boards that take step/direction signals or a PWM signal and give the the 0-10V signal.

You have to have both boards and the motor speed control's output voltage needs to match the spindle motor.

[HPearce]

Check out the cnc4pc web site, there is a wiring diagram for a KBIC speed controler..... that is the one the sherline uses. it will take a standard 0 to 10v to controll it, not sure what the g540 puts out?

[cmanning]

Check out the cnc4pc web site, there is a wiring diagram for a KBIC speed controler..... that is the one the sherline uses. it will take a standard 0 to 10v to controll it, not sure what the g540 puts out?

Thanks I'll check that out. The G540 can output at least 10v, and I think up to 12v.

Chris