dang....another JUKI LU 562 issue

[mixmkr]

So...following the Navy manual, (and Uwe's vids)  I felt good about all the adjustments I was able to do.  Set timing, presser foot height, centered needle (verified) in feed dog, presser foot lift and relative presser foot lift...   all went well.   Sewing great.  So...after running a bobbin or two thru test material, of course I put a "job" on the machine and the sucker was breaking upper thread after a couple of stitches.  Cleaned the bobbin case out, lubed sparingly...etc. 

My problem appears to be the upper thread when traveling around the bobbin case, is not easily making it over the little notch in the bobbin case, that fits into/under the needle plate.   There is a little slop in the notch and I'm under the impression the stud protruding out of the bobbin case kinda rides against the notch on the side away from the operator..  Guessing there's about 1/16" slop in the notch, so the bobbin case isn't just held really firm.  Also under the impression this is normal.  But why the thread is not clearing over this notch, I don't understand.  Being new enough to all this, I'm presuming it has to as well (dumb question??)

I'm learning bunches, but when one problem is solved, the next one gets in line.   What's the deal with the upper thread catching (and then of course breaking) on this little stud that sticks out the side of the case?

 

btw...Uwe...if reading this... routing the slippery thread around that pin on the first upper tension disk seems to be helping to keep the thread between those disks and not popping out. 

[Uwe]

Make sure your bobbin case opener is adjusted properly. The bobbin case tab in the throat plate cutout needs enough wiggle room to let the thread through. The tab wants to rest against the far edge of the cutout because of the clockwise rotation of the hook. The tab needs to be pulled back (counterclockwise) at the right moment just long enough to let the thread pass on the rear. The bobbin case opener arm does this.

To adjust it, turn the handwheel until the bobbin case opener arm is at its right-most position. Keep the handwheel in this position. At this point the bobbin case tab should be pulled far enough from the rear edge of the throat plate cutout to let the thread pass through. The bobbin case itself should have only a tiny amount of play without binding between hitting the bobbin case opener arm and hitting the front edge of the throat plate cutout. If that's not the case loosen the screw that hold the bobbin case opener arm and slide the bobbin case opener arm until the tab is almost, but not quite, touching the front of the throat plate cutout.  The bobbin case should be able to wiggle a tiny bit to make sure it doesn't bind.

I had one new throat plate that just didn't have enough of a cutout and I had to file and enlarge the cutout and polish it to let thread pass through properly. Don't start filing until you're positive it's necessary and don't file the throat plate while it's mounted in the machine! 

Lots of words, sorry. Perhaps this video (about a different topic) shows how the bobbin case opener pulls back the tab just as the thread needs to slip through. 

 

Edited January 6, 2017 by Uwe
typo

[mixmkr]

Uwe, I don't have the words to thank you...and such an immediate reply COMPLETE with video. 
The bobbin case open on the JUKI seems to be a bit touchy, but after getting it screwed just right, the stitches are now perfect again.

I need to take you out to dinner or whatever I can do.  

Just to let you know, you're putting smiles on my face.   Thanks soooo much!     (and what I've learned from you and these forums has been nothing short of exceptional)

[Gregg From Keystone Sewing]

Nice, I enjoy seeing people helping out people around here, that's what it's all about.