VFD updates - The initial experiment is coming along nicely with one exception.
The first tests made use of a single phase 240 V input source. I randomly selected a "pole set", the right hand set of three terminals in the motor junction. After some initial programming to enable the pot and keypad, I had the motor spinning nicely at 60 Hz output, about 1800 RPM. The current draw was higher than I thought. This is a 10 Amp / 3HP VFD, and this motor is drawing 7.5 Amps. It's a good thing I bought a "bigger" VFD.
I set the accel and decel rates... it's nice to push a STOP button and have the spindle braked to a halt rather than having to apply a manual brake. 4.0 seconds is a nice accel, while 1.5 seconds for decel is perfect.
Thinking I was hooked to the slow set of motor junctions, I swapped the 'gator clips to the other... and found that the motor output was identical.
Hmmm. Maybe the function of the original switch was to route power to ALL SIX motor junction screws. I'll have to sit down with an ohmmeter and map that switch. It may be as simple as putting a shorting bar between the corresponding motor junctions to activate the high-speed.
The only bad part so far was that when I tried to feed the VFD input 3-phase power from my Phase-A-Matic, the VFD tripped (error), and the error code indicated "DC bus overvoltage". I'll need to do some research there. The VFD manual is almost 200 pages! There's plenty of protective logic built into the VFD, so short of a horribly incorrect wirng job, it looks like it will take care of itself.
Hu, thanks for the advise. I'm going to get a 115V AC fan and mount it on top of the motor. It'll run all the time to augment the internal motor fan, which will have little airflow at slow speeds.
I'll keep plugging and get some more data and pictures up. So far so good! The whole idea behind this VFD was to get rid of the rotary converter, and obtain variable speed to boot.
Swede