Spindle speed control via VFD on a Vari Speed 2J Bridgeport

With my VFD I can control the motor speed from only a few Hz up to 200 Hz. It's my understanding the motor produces the most power at 60 Hz. If my Varispeed head was cranked up to 3,500 and My VFD try's to command 100 RPM I'll have no power at all. In Mach 3, I utilized the step pulley feature where I carved out RPM ranges so the VFD had reasonable range it could work within. I had it configured My Varispeed head as if it was a step pulley head something like pulley 1 set head to 1,000 RPM, Pulley 2 the head set to 2,000 RPM Pulley 3 head set to 3,000 RPM. Any advice on how to do this in Linux CNC? I've done a good bit of searching, but I haven't found anything yet, no doubt I'm using the wrong search terms. Again I do have linuxCNC altering the VFD speed, but I need to set speed ranges by "Pulley".

Thanks!

Roger

I think instead, I'm just going to have the spindle switched on and off by computer and I'll just dial in the speed with the vari-speed manually. there were a couple of times where I had issues being on the wrong pully setting. I'm thinking I'll just take full manual responsibility for the speed since it can't be fully automated. I suppose someday I could get fancy and mount a stepper to the Vari-speed control.

I did cut my first parts in Linux CNC. It worked just fine. I managed to break an endmill, but that was my fault, not the software.

My Varispeed is not motorized. In Mach, I set it up as if it was a step pulley head. Rather than move the belt to pulley 1, I'd dial the vari-speed manually to say 1000. Pully 2 might be 2,000, etc. I also currently have no encoder for any feedback

I think I'm going to skip this fancy setup and just dial the head to the speed I need and keep it simple. Although I'm still interested to know how this would be accomplished.

Thanks