Thread Jumping Off Tension Spring Think Juki Lu -55

[jerry895]

I have a Juki LU -55 which I believe is a clone of a Singer 111W-155. First off I am new at the whole sewing thing, I bought the machine not working and found a retired sewing machine guy to time it and get it working for me. My problem is when sewing at a nice slow pace ( servo motor ) every now and then the thread pops off the disk to the left of the tension disk, I start out with the thread being controlled by the spring and the next thing I know the thread pops out of the groove. Any suggestions? I want to learn more about my machine and not just call my guy.

[Constabulary]

Are you sure that the thread runs the right path?

[Wizcrafts]

Add back tension to the top thread by wrapping around the holes in the guide before the upper tension disks. This may cause too much top tension, so back off the beehive spring nut to compensate.

OR

If still no happy happy, feed the thread under the little stud on the right side of the tension disks, then up and over/inside the disks. The sharp turn up and down should keep the thread in the center of the disks.

OR

Some thread, especially black bonded nylon, is very springy. Try a different spool or brand of thread.