Vintage Sewing Machine Repair Answered
I acquired a older sewing machine at a thrift shop, but it needs a little work. There appear to be two issues, possibly interrelated:
-The motor makes a strange intermittent screeching noise after the machine has spun up for a few seconds, and smells like ozone. I think the commutator is arcing. I'm not entirely sure though, I'm no expert on universal motors.
-The hand wheel sticks at one point during the revolution. This occurs when the needle, as well as the feed dogs, are fully up.
I'm guessing the sticking is demanding too much toque from the motor, causing the weird sound and smell. Regardless, de-gumming the thing and getting smooth motion seems to be the logical first step. I've applied mineral oil to all the moving parts I could find that looked like they would benefit from it. Now the motion is extra smooth, until it sticks, just as bad, and at exactly the same place.
I'm a bit stumped. Any ideas on what I should try next?