Crazy stitching

[Clintock]

I cannot figure out what is wrong with this machine. It's sewn one holster and I've played around on scraps a bit. The (locking knot?) keeps showing every other stitch. Sometimes on bottom sometimes on top. Here's a pic of what I mean.

I've taken the bobbin out and respooled it. Making sure it's laying flat and the thread doesn't stick out the side hole. Installed it making sure it's turning counter clockwise. Cut the thread off at the spool and re threaded making sure I went through each keeper or hole etc.  

I have not adjusted any tensioners on the machine. Honestly I'm scared to for fear of not getting it back where it's supposed to be. I know it's nothing major but I can't justify spending that much money on a machine just sew test runs.

Any help would be appreciated!

[Clintock]

I cannot figure out what is wrong with this machine. It's sewn one holster and I've played around on scraps a bit. The (locking knot?) keeps showing every other stitch. Sometimes on bottom sometimes on top. 

I've taken the bobbin out and respooled it. Making sure it's laying flat and the thread doesn't stick out the side hole. Installed it making sure it's turning counter clockwise. Cut the thread off at the spool and re threaded making sure I went through each keeper or hole etc.  

I have not adjusted any tensioners on the machine. Honestly I'm scared to for fear of not getting it back where it's supposed to be. I know it's nothing major but I can't justify spending that much money on a machine just sew test runs.

Any help would be appreciated!

As you can see in the pics it's not all the time. And on this piece of scrap it's mostly on the bottom With only only one row being on top. 

[dikman]

Type of machine?

[Clintock]

Thought I put it in the tags. It's a cowboy 3200

[dikman]

My first thought is something in the thread path is causing the tension (probably upper) to vary slightly during stitching. Can you attach a photo showing your thread path? (It will help the more experienced here to diagnose the problem). There can't be too much wrong.

[Wizcrafts]

I would watch how the thread uncoils off the spool. Maybe it is hitting sticky spots, then loosening, then grabbing? Twisty thread can also cause the knots to move.

I also recommend that you wind a different bobbin with the same thread and see if the problem persists. Some bobbins have a longer end to end profile than others. Over-length bobbins squeeze the bobbin thread against the shuttle driver frame at certain points of rotation, as the thread feeds out. I

I've actually had to sand down and polish a few over-length bobbins for my harness/holster stitcher.

[Clintock]

Here's the thread path pics 

[Clintock]

I've tried it now with 3 different bobbins. I've watched the thread uncoil while I was stitching. It's coming off fairly easy. And not hanging up anywhere. It's crazy cause  it started it outta the blue. 

[Evo160K]

Is the needle in correctly?

[JLSleather]

Isn't the thread supposed to wrap around this disc all the way, THEN go up over the pin?@

[Clintock]

Needle is in right. @Evo160K  groove on left and flat spot on right  

@JLSleather sposed to be a wrap anna half. And it is. Or am is it sposed to wrap around that post that it's going over too? 

Btw this is cowboy brand 277 on top and bottom. Thinking I may go to a smaller thread on bottom. 

Edited June 16, 2018 by Clintock

[RockyAussie]

If you are sure it is coming through the thread path on top without any tight and loose happing as you pull it through have a look and make sure that your foot pedal is not letting the spike that separates the tension discs at the back touch. If there is no gap from the discs it may be enough in operation to make the tension loosen and tighten a little. Make sure your foot pedal where it hinges is moving freely because if it gets caught up it could be holding the tension discs apart as well.

[Clintock]

@RockyAussie checked and good. 

[Wizcrafts]

It could be a problem with the leather varying in density as you sew. Or, the bobbin thread could be getting twisty, forming microknots as it passes under the tension spring.

[Clintock]

@Wizcrafts there is a little "pop" when stitching. Always thought it was the thread popping as it came over the bobbin. The leather is WC 7/8oz glued and doubled. I believe I may have most of the knots worked out. Doesn't do it every other stitch now but sometimes. I adjusted the tensioners a little. Is there anyway to "reset" the tensioners? 

[RockyAussie]

It looks like you have your thread return spring held at the uppermost height in the picture. Does the thread start to go slack at the needle just as it is entering the leather? That is what it should be doing and It may make some difference. When you say you adjusted the tensioners a little what do you mean? The tension disc adjustments or the foot pressure or the bobbin spring or?

[Bugstruck]

You could try running the top thread through the upper tension then back through the eylete before descending to the lower tension. One of the clone vendors recommends that path to keep the thread well secured in the upper tension. I have had your experience and tried that alternate thread path with success one one occasion. The thread angle from the upper tension to lower looks agressive using that path but it has not caused me any issues.. Worth a shot. Sometimes the thread looks well seated in the upper tension but isn't. 

I don't know this but suspect the issue occurs when releasing foot pressure for turns or other reasons. The clones and presumably the Juki start releasing upper tension nearly as soon as the foot starts lifting, so you don't have a release delay there like many of our machines. Nothing wrong there, just how it is engineered, and the top of the discs stay tight which helps keep the thread where it belongs and engaged. Does ride up on rare occasion though and can give your results.

[Bugstruck]

I should clarify, they do have a tension release delay but not as late in the lift as many machines. My experience.

[Clintock]

@RockyAussie not sure what piece you're talking about that's at the uppermost point. thread does go slack just as needle penetrates leather. Since most of the knots were on bottom I adjust the discs. Going tighter up top till knots starting showing more on top then slacking off till the disappeared in the leather. They may not be right and the tension might be off but it's better now. Mostly does it in a curve now or a sharp corner. 

@Bugstruck I've seen a video on that or read it somewhere. Never give it a try but I guess it wouldn't hurt. Will double check to make sure disc are closing fully when foot is down. 

[Bugstruck]

I was in the middle of a post and lost it. Tablet is squirrelly.... The wide range of thread our machines throw has an impact on tension release point. I usually sew 207 so that is what I was commenting, occurs fairly low. Run 346 and the release point is higher, closer to what we see on the narrow thread range machines. We ask a lot of these clones and they do a good job.

What Rocky Aussie meant I think is the thread tension spring should seat on it's built-in rest just as the needle enters your material. 

[Clintock]

@Bugstruckthat spring with the loop holding the thread coming off check spring does rest on the stainless seat. I tried to wrap the thread around the upper disc tensioner but I don't see how it can be done with the tension release hits it when you raise our foot. It puts my thread at an angle that it'll glide over the end of that "disc splitter"? Changed out bobbin again. So I'm on the 4th one. Still the same. 

 

 

Is there a way to reset all tensions on machine and start over? There has to be. But where would one start?

[Wizcrafts]

@Clintock

Try this. Pull the top thread out of the second hole in the top post and just run it through one hole. Then loosen the screw on the thread loop in front of the tension disks and push it as far down as it can go, then lock it in place. The rational is that by lowering the thread guide it will feed the disks from a greater downward angle, better securing the thread inside the disks.

Pay attention to whether the disk separator is interfering with the full closure until you lift the feet. It should not push them open at all until you lift them, nor should the point hit the thread as it feeds down to the roller disk.

Resetting the tensions means remembering how tight they were when you got the machine. Just set the bobbin tension for a moderate pull (not too tight, nor too loose), then balance the knot position with the upper tension nut. You can play with the bottom roller tension to see if it makes any difference. But, to have any tensioning affect, it needs at least 1.5 full turns before it exits over the pin. Anything less and the thread will just slide around the roller disk.

[Clintock]

@Wizcrafts tried just going through one hole in top post. Changed the angle of the loop you were talking about. The loop bottoms out on the disc separator. It did move about a 32nd. Had to completely remove top discs and spring to access screw. Reinstalled and it's better. In a run of about 4 inches I had that crazy knot only twice. 

I do have a wrap anna half around the main tensioner before overlapping side post. You can see in the pic. 

 

[Clintock]

UPDATE:

found a piece of thread between what looks like a race behind the bobbin. So far so good except on corners but that's prolly me. Any advice on what to do to correct that would be great

THANKS TO ALL THAT GAVE INFO ON THE MATTER!! I really do appreciate the time you took to help me. 

Edited June 16, 2018 by Clintock

[Wizcrafts]

Ah yes, the old thread stub trick.