Lathe Motor Making Loud Noise On Start Up

[Gator-J]

Hi all - not sure where to post this, so here it is.

I have a 3 phase 3HP motor with an electric brake on my Standard Modern lathe. On start up it makes one hell of a racket. Lots of banging from, what sounds to me to be, the electric brake. Sounds like gears grinding, but I am guessing it is the electric brake turning on and off really fast. It stops after a short time once the lathe is up to speed. This time is determined by the speed I am starting at. At 50 RPM it may be about 0.25-1 seconds, at 1000 RPM it is closer to 3-4 seconds. It appears to run fine after the noise stops.

This is a new noise since I got a new phase converter. I had to get a new converter because i was stupid and did not realize that my kids had messed with the controls and the lathe was on when I turned the converter on. That shorted the phase converter motor.

I don't really want to take it off and cart it to an motor shop if I can help it.

Any ideas?

I think I figured out how to upload my 1st video:

 

[dutchgray]

Check the generated leg from the phase converter is not running any controls on the lathe, since its not a real phase weird things can happen. This should only be if the new converter has been connected differently than the old was.
If not then remove the brake assembly and see what that does.

 

[Gator-J]

So, disconnecting the brake does not work. I think it is power on open, power off closed.

I did manage to melt down a HF mulitmeter testing the legs. Not sure how, but it happened.

 

[VocaTexas]

Gator, you might try posting here: hobby-machinst.com