Juki LU-563 keeps thread jamming

[hemiyota]

I picked up this machine about a month ago. Got it cleaned and oiled. Threaded it and started practicing on vinyl. Got tired of practicing and decided to actually sew something.  Made a cover for the machine. Couple days later, tried to sew again and no way. Thread keeps jamming. It will actually pull the top thread, that I'm holding, into the machine  and jam. Popped the safety clutch once. Set the hook timing. Same thing. I've had it apart, those 3 little screws, about 8 times. It just keeps pulling thread in and jamming.. Nothing was changed since I made the cover, it just quit....Any ideas?

[friquant]

Try this: Start and end each seam with the take-up lever at its highest point. (Otherwise the machine will yank the thread out of your hands when the seam begins)

Also post a photo of how you've got the top thread threaded, from spool to needle eye. Just in case it's misthreaded.

And check the timing. I like to check where the hook shoulder is when the take up lever is at its lowest point. If the timing is retarded, the take up lever will yank hard on the thread before the thread reaches the apex of its path around the bobbin.

If still not working, can post a close-up video of the needle and bobbin area with the bobbin cover off. Turn the handwheel very slowly for the video, on the order of ten seconds per revolution, so we can see the interaction of the different pieces. Hope this helps!

[kgg]

5 hours ago, hemiyota said:

Thread keeps jamming.

A couple of questions:

i) What are you trying to sew?? Leather or fabric and how thick??

ii) What size of thread are you using as a top thread??

iii) What size of thread in the bobbin??

A few photo's of the top threading from the thread spool to the eye of the needle would really be helpful in narrowing the problem down.

Assuming your hook to needle timing is correct check

i) incorrect threading

ii) damaged bobbin case

iii) faulty bobbin or installed backwards

iv) improper tension settings bobbin and top thread

v) needle bent

vi) wrong system needle. 135 X 17 X needle size is for fabric and 135 X 16 X needle size is for leather,

vii) wrong size of needle vs thread size

viii) dull or bent bent needle

ix) debris buildup in or under the bobbin area.

x) threads (bobbin and top thread) not being held for the first few stitches before being back stitched and locked.

kgg

 

 

 

[hemiyota]

It was sewing perfectly fine just a couple days earlier. Nothing was changed. Still threaded the same. Sewing vinyl. T90 top thread, not sure of bobbin, but it isn't too small or large, and worked fine for all the other sewing I was doing. Set the timing and needle height. I'll take a video.