In a 111W155 Singer or equivalent Consew, those familiar will know how the bobbin is loaded. That is, the bobbin is loaded in the case after lifting a latch on top. Then the bobbin thread comes out of the case through a slot and contines under the tension spring.
With that description, sometimes (definitely not frequently) during sewing the hook will pick up the top thread (needle thread) and during the wrap around that thread will get caught in the slot of the bobbin case that I described above.
I have checked the bobbin case for barbs and gone over the tension devices pretty closely including the take up tension spring but can't figure what might be cause the top thread getting caught in the slot of the bobbin case.
Timing is good, actually the machine sews good. I am probably correct to say; what few times it has happened, was when stopping to make a turn or to set the fabric being sewn better.
Again, it isn't consistant but happened couple times today.
Nylon 69 thread was being used.
Any ideas? Could it merely be a variance in thread tension, ever so small, that is caused by slight wear in tension disc or upper thread path?
Doyle
not any help but mine time to time thread catches under the bobbin case latch
Quote from: Mike on October 02, 2013, 03:28:03 am
not any help but mine time to time thread catches under the bobbin case latch
Me too. Usually when I'm rotating the wheel by hand.
Doyle: I would also suspect something in the tensioning. Perhaps the check-spring is "over checking", causing the top thread to be too taut as it wraps around?
Thanks guys,
I made an ever so slight tension adjustment to the take up spring and by golly it made a significant difference.
The timing of the take up spring with respect to the needle position wasn't touched, there are two different adjustments to the take up apparatus, in case.
Refreshing situation as I completed a project on the machine without a hitch.
Doyle