Stitching Forming Loops

[thunter9]

Color can sometimes read it's the same size but it isn't.I'd still look for lint buildup

[thunter9]

To get more even tension loop the thread through the eye on top of the machine before it goes under the attention spring hey just trying to help. Run the thread like you would and through the needle pull on the thread how does the tension feel. Compare it to the bobbin tension. They should be equal that's what you want

[dikman]

Sorry guys, I was talking about the wrong machine. This is what happens when I try and do more than one thing at a time! The used spool is on the Pfaff - that's been cutting the thread, but I've found a very small nick on the outside of the shuttle assembly which may be the problem.

The spool on the Singer is a new, previously unused one and looks good, so I don't think that's the problem - but I won't rule it out just yet. I'll swap spools to prove it. The fact that it works for a while suggests the tensions are reasonably close and everything is working correctly, so why does it suddenly start causing loops? That sort of points to an outside interference, and the spool is the only thing "external" to the operation.

Most puzzling.

[Uwe]

Is this the machine that you broke two needles on yesterday? Maybe your safety clutch popped and timing slipped a little, or is still slipping as soon as the going gets tough?

On my Tacsew, which was (and still is) having major timing problems, I noticed one setting where it made stitched, but the hook would occasionally catch the loop AGAIN after it had be pulled around the bobbin. If timing is off, no amount of thread tension adjustment will fix it.

I'd flip the machine back and turn the stitches slowly by hand to make sure everything is happening exactly as it's supposed to on the underside.

[dikman]

Nah, that was the Pfaff, it obviously decided not to like me yesterday.

I've already checked the timing, but yep, I guess it's time to start double checking everything again. It has to be something relatively simple.

[gottaknow]

Increase your latch opener gap and make sure the notch on the bottom of the throat plate is nick free. If the notch is beat up some, don't widen, just make it smooth. That is all.

Regards, Eric

[DrmCa]

Not sure if it helps, but I had loops previously when trying to stitch too heavy leather. Is the OP pushing the machine's limits?

[dikman]

Nope, Piece of veg, about 3-4 mm thick. Machine should handle at least 10mm. Going down later to finish off the Pfaff and then start on the Singer (again).

[dikman]

FIXED IT!!! I thought I'd checked the hook timing, but I obviously confused myself and it was the 111W that I'd re-adjusted. (BIG senior's moment, that's what comes of trying to fix three machines at once!) Anyhow, the needle bar was too low and the needle guard on the shuttle was actually pushing the needle sideways (can't help wondering who had adjusted this previously). I re-adjusted it, but it still did it. I then checked the thread takeup spring and noticed it was only operating on the first couple of coils. Turns out it was a very tight fit in the hole in the machine body, so I modified a spare spring from a junked machine. Unfortunately, this wasn't the problem either. I started running some stitches, very slowly, and watched the takeup spring. I increased the speed and when the spring went slack I stopped and looked at everything. Bingo, the thread had jumped out of the tensioner!! No wonder I hadn't seen it before, because pulling on the threads had pulled it back into place each time.

I pulled the tensioner apart, but couldn't see anything wrong, so I polished the inner faces of the discs anyway. The 3-hole thread guide next to it was in the same position as in the manual, but I shifted it in as close as I could to the tensioner. That was it, I ran stitches down the edge of an old belt and only missed one stitch (probably my fault). So Constabulary and hunter were right all along, but because everytime I looked it was ok I concentrated elsewhere. A nasty little problem, it's the last thing I would have thought could happen.

Also, I fixed the Pfaff. Another tension issue, but this was a tricky one. Mine didn't have a tension release rod fitted (to open the tension discs when the foot is lifted) so I made one. The Pfaff has this wonderful bit of design where, as the presser foot is lifting during sewing, the slide that pushes on the release rod is also lifting. Which means that the length of that rod is absolutely critical. Mine was a fraction too long so as the foot lifted it released the tension discs and allowed slack thread in the stitch cycle! By carefully filing the rod I got it to the point where it didn't trip the discs while stitching but would still release them when the lever was lifted by hand.

All in all, a pretty good day and my knowledge and understanding of these machines has increased tremendously. Mind you, if it wasn't for this forum I hate to think of the strife I'd still be in.