You can get narrow gap gauge sets are most any auto parts stores.

Joe

pretty sure the copy rite has expired by now.

1.5 is your usual setting? That's terribly low...

I agree, that should be a snap,..

It would be worth trying the same sort of thing on a test sandwich that doesn't have glue in it...

Shredding indicates abrasion - needle, glue, burr somewhere... it's possible the burr is somewhere the thread doesn't normally feel it, but with the added bulk and possbility of even a little deflection of the needle it could be just enough.

If the spool jumping wasn't from the bobbin case teleporting, it got a giant fast yank of the thread. It would be worth investigating the whole thread path for burrs and other snag spots.

It might be a good idea now anyway with the bent needle and displaced bobbin case. There may be a new burr. :(

Is there any chance at all that when you speed up, you tend to push the fabric rather than just guide it? I used to do that a lot. When the motor first starts, there's a little bit of lash to take up at the handwheel because of that motor gear, but I don't -think- it would cause a problem here....

When the machine runs faster though, like anything - the more motion, the bigger a deal everything is. Something just a little out may be a big deal at higher speed.

Update: I got the measuring equipment and, following Joe's instructions, the gap at the top (D) was too big. I adjusted it. I tested it. The first five tests of very fast sewing were great and on the 6th test, the thread again frayed and came unthreaded. I decided to test it on an actual quilt. The stitch was just great for the first part of the seam and then frayed again and unthreaded. I rethreaded, checked the bobbin, and tried again. This time, even on a slow speed, not only did it fray and unthread, but it unseated the bobbin again AND CURVED -- not even bent -- the needle, a Singer 16. Grrrrrr! I cleaned out and oiled the bobbin area, rethreaded, reseated bobbin, etc. This time I gave it a Schmetz 90 needle. I was aggravated by then and went off to treat my sunburn. I'll try again tomorrow.

I think I will check along the whole path for any burrs, try a different thread (previously done), and see about the difference a needle makes. I may have to play with the gaps again (thanks, Joe!). I'll just do one thing at a time.

I'm hesitant to say timing; I think it is more likely to be a bobbin area issue. Do you agree?

Why won't that darn machine work right???

Cricket

Cricket, look for something ON the bobbincase that's grabbing thread.
Here's my theory: Twice the bobbin case has been yanked out of its position. I don't think this is really supposed to be possible in regular use. Not with that retention system. The only way I could see it dislodging would be with a giant yank to the back and upward. Pretty much what the take-up lever would be doing to the thread that's probably yanking the case out of place. The other place I would check is on the thread path to the right side of the take up lever. If it were caught there, and the TUL wanted thread delivered from the right side, it may yank the case out of place while trying to grab thread from the other side. Does it pucker the seam at the same time?

You could also try the throat plate and bobbin case from your 401. Heck, even the tensioner. That could eliminate 3 places for burrs.

Cricket,

You need to check and adjust all 4 specs they work together. And as Tammi said said, check for burrs or other things.

When I set the gaps on these machines I try to set them in the middle of the allowances. So far that's worked good for me.

If you needle is being bent, there has to be a physical cause for that. Either the hook is out of time or the fabric is being pulled and is deflecting the needle.

Joe

Hi Tammi. Your theory sounds good to me, so I went over every bit of the entire thread path. I found one slightly rough area after the tension, but not on the exact tread path.

The seam does not pucker.

I would have tried switching parts with the 401, but at this moment, it doesn't seem necessary. I've sewed three long, very fast seams with no problems so far, but have not yet tried it on a quilt. The difference is that I followed Joe's instructions and measured and adjusted the part that holds the bobbin in, and I used a Schmetz 90 needle. Oh, I also flossed the tension thoroughly. I did catch some shredding there. I haven't done anything about that (crocus cloth) yet because of the three good seams. My philosophy is that "if it ain't broke, don't fix it."

Thanks, Joe. I did check and adjust all 4 specs together. Sorry if I wasn't clear.

Good idea on setting gaps in the middle. I'll remember that and do it next time.

Maybe I am pulling the fabric. It is hard to handle a quilt in the space of just the cabinet. I don't have any other tables upstairs to support quilts nor room for them. I do have them downstairs but I also have knee issues and stairs are not doable right now. I'm guessing it isn't out of timing because the stitch remains perfect. Would you agree? Also, I see no needle marks or indications of timing problems. Unless you know something I don't? If so, do tell, please.

I will try to quilt my quilt and I'll let you know how it goes.

Cricket

Change/reverse your needle.
This should correct your problem of machine coming unthreaded

yes. that's what i am thinking too. in most cases, skipping thread/unthreading issues are due to needle. get a new needle.

Cricket,

Here is a trick I tried with Rusty, my rusted 99K. His thread path was rough with rust and that was causing trouble.
So I got some really thick thread, probably carpet thread, coated it with jewelers rouge and then ran it through each guide as if it were the machine doing it. I used a back and forth stroke with the string until it broke from the friction. Then I cleaned out the thread bits and rouge and noted a huge improvement. It's just and idea to try for the burrs if you still have some.

Joe