Motor on Mark 7 seems "stuck"

[Ash1562]

Hi all

I've been using my 60's vintage Mark 7 for about 6 months now and she's been running fine. I make sure to add oil every 6-8 hours of use, or sometimes even every 5 hours after running the lathe for extended periods.

Today, i was using it as a drill press and after about 20 minutes of on and off use (boring out a few holes for a wine rack), the motor didn't turn on. It makes a humming sounds as if it's "stuck" and if I try to turn it by hand, it'll want to start but just doesn't. I added oil just in case, no help. After trying to get it to start spinning a few times, it popped the breaker so I assume the engine is strained, somehow.

Any tips? I've never seen this before so I'm pretty much at a loss.

thx
Ashkan

[JPG]

Mark VII? Ya I know one tag says Mark 7(ignore it!).

With a soft face hammer whack the side of the headstock. The start switch(or start relay if applicable) has some crud stuck in the points preventing the contacts from completing the start circuit. Hopefully that will cause the crud to fall out.

If that fails, blow out the interior of the motor(gotta get inside the headstock to do that).

If that fails, disassembly of the motor will be required.

Regardless, STOP trying unsuccessfully to start it.(repeatedly/often) That leads to burnt run windings.

[Ash1562]

JPG - as always, thank you for the great response.

You won't believe (or maybe you will) the problem: the relay had come loose and fell of the motor from where it's normally fastened. The leads were touching the head stock housing and basically shorting out cuz now the head stock metal housing was part of the motor circuit too. I managed to get it back on and have to open up the head stock to screw it back but it works perfectly fine now.

Any good videos or tips on how to open up the head stock? I see a lot of Mark V how-to's so I assume it's more or less the same.

[edma194]

It should be the same as a Mark V until you want to take apart the drive assembly, and then it only varies a little.