pfaff 145 binding up intermittently

[JDC]

Hey everyone! I'm new here and need help. I recently bought an old very well used pfaff 145 from where I work. They were selling it because it was dropping stitches when they were making piping, which was the only job it did for years. It worked fine at lower speeds and with normal thread, but they were asking it to go at essentially warp speed using monofilament thread so it didn't fill the need anymore. I got it home and went about figuring out how to use it. I found that the monofilament had worn some parts pretty badly in a few places and it was fraying and breaking thread in those places. I sanded the worst bits smooth enough that it wasn't too bad but I couldn't possibly keep up to the speed they had it set to, so I changed the pulley ratio. Now enter the problem: something seems to be loose in there somewhere. I can hear it rattling at a couple of specific spots and the hand wheel definitely gets tighter when the rattle occurs. Some times it even stops me hand turning it. Once it even stopped the motor. I've had all the inspection covers off and don't see a source of the rattle or binding. I remove the machine from the table and set it on its end to hand cycle it to see if I can see something at a different angle but then there's no rattle.

 

Does anyone have any experience with these or similar machines doing something like this?

[shoepatcher]

thread size and needle you are using?

glenn