First off, the switch was no good and I rebuilt it without too much trouble. I got the mill running. I drilled some hold down holes in a 1-1/2" aluminum plate to start milling it today, running it on low speed. No problems.
I set it up to start milling, and turned it on to high speed. It ran for a few minutes, then the motor started speeding up. I looked up and a puff of smoke came out of the motor - I snapped off the switch immediately, of course.
On this mill, the wires are labeled (apparently by the manufacturer) such that 5 of the 6 are labeled differently at each end. They go like this, switch end/motor end: 1U/1U; 1V/1W; 1W/1V; 2U/2W; 2V/2U; 2W/2V
When I checked the wiring at the switch against what I had written down before I took things apart to repair the switch, I found that I had swapped two wires at the switch: 2U and 2V. But I don't think that is the problem.
The wire map shows that for Low Speed, power goes to 1U, 1V, 1W and 2U, 2V, 2W are open. For High Speed, it shows 1U-1V-1W tied together, and power to 2U, 2V, 2W. (At the motor, there is a double-side terminal strip, 1 UVW and 2 UVW. All the wires and their markers match at the motor terminal strip.)
But that ain't how things were switching! I disco'd all the wires at the motor and did a continuity check at the switch connectors. This showed another oddity: On Low Speed, power went to 1U, 2V, 1V with the rest open; and on High Speed 1U-2V-1V tied together and 2U 1W 2W had power.
BTW, the motor was turning in the right direction.
It is a simple matter to straighten out the wiring at the switch terminals w/o tearing apart the switch again.
But now I am wondering if it matters which way the wires from the converter to the switch are run to which terminal? Two wires from the single phase go to the converter and also the switch, and a third wire from the converter goes to the switch. Should this third wire be the one that does not switch for directional control? I thought it didn't matter, but now I am wondering.
I checked the motor with a digital ohm meter. On the scale for 200k ohms, it reads within 5-10% of a readout of 0.35 between all motor leads on the #1 side, and again on all leads on the #2 side. I'm hoping the motor isn't destroyed...is there any hope?
Any thoughts or suggestions before I try to power it up again?