Mini-Lathe Electrical Issue

Correct. The emergency stop button is the cover for the green "on" button and red "off" button.

The MicroMark website claims the motor to be a DC motor. Given there are no brushes, I guess it's a permanent magnet motor fed by 3 phases?

I believe there is a electronic latching mechanism to hold power on when the green button is pushed and power goes away when the red button is pushed which releases the latching mechanism. I'm thinking this is where the issue is. If I hold the green button, I can sometimes get the motor to run. No fault light ever comes on.

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I would wire a toggle switch in, to remove that "safety"switch.
 
I pulled the switch out and tried to measure the resistance with a DMM, but it seems to jump around. Is this a latching switch/relay or just a switch?

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I looked this part up and it is an electromagnetic switch. So, it is basically a latching relay. I was able to jumper 120VAC around this switch to the lathe directly and it ran fine. So, I guess the switch went bad. Amazon has an exact replacement. On order.
 
If the green light goes on when you press the power switch, and the power switch is not engaged (motor is not turning) and the green light goes off when you don't press this button, the circuit that keeps the power switch active is open. This could be caused the safety switch of the spindle protection cover. You should check the witch and/or wiring of that switch (temporary replace the switch by a wire).
This switch is a safety switch that must release in case of a power failure so that the motor isn't turned on if the power is restored.

I had the same issue and found a bad connection (lose screw) in the safety switch.
 
I'm not sure what you are referring to when you say safety switch. I only have the power switch. There are no other switches.
 
devils4ever said:
I'm not sure what you are referring to when you say safety switch. I only have the power switch. There are no other switches
Click to expand...
Some mini-lathes have a micro-switch on the pivot to the chip guard. It can also give grief on occasion. Typically it blocks the spindle motor rotation, unless the chip guard is in place. Disregard if there is no chip guard...
 
I’ve replaced this switch in both my little machine shop mill and micromark lathe. I now keep a spare switch handy just in case
 
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