Help with tension knobs

[PEU]

I'm new to leather sewing, been practicing for the whole last week and still have some doubts. There are two types of tensioners in my machine, and I guess this is the same for all machines. One squeezes the thread and the other is a wheel with felt on the sides, I mean, this one:

 

I tried one loop, and two loops as seen in the photo, more and less tension, and every now and then, the thread unspools and get stuck on the tensioning spring. 

Here is a YouTube video of the machine slowly stitching: https://www.youtube.com/shorts/4s-va_6a7Ok

Maybe its low quality felt, or maybe is something else you can teach me, because I'm lost on how to prevent this unspooling. If you watch the video you can see that I modified the the thread guide into this knob by separating the incoming thread from the outgoing one (OEM part was a big loop with each one going its way without constraints)

Today I stitched 6 sheaths successfully, but yesterday while practicing, it got stuck twice breaking the thread.

Thanks in advance!!

 

[kgg]

13 minutes ago, PEU said:

Today I stitched 6 sheaths successfully, but yesterday while practicing, it got stuck twice breaking the thread.

To get better help with your problem it would be helpful to know what machine you are using, thread size that you are using for the top and in bobbin, needle size also a couple photo's of the thread path from the spool.

kgg

[PEU]

Machine is Sibyer sb-6180-1 extra heavy duty. Using 270 bonded thread on top/bottom and 794 25/200 diamond needle.

Here is a video I made for a local friend (I speak Spanish in it) it was made before the modification I wrote above, but the path is the same: https://www.youtube.com/watch?v=18aE_q1exxw

Thanks!!

[CowboyBob]

Are you holding onto the needle thread for the first 3 stitches?

[PEU]

4 hours ago, CowboyBob said:

Are you holding onto the needle thread for the first 3 stitches?

Yes I do, practiced this to get the best results and I think I finally nailed on the tension of the first 3 stitches.

Also I don't use the lever to change motion direction, I just turn the sheaths 180 deg, I found this way was better for keeping the stitch tension. Thanks

[Wizcrafts]

54 minutes ago, PEU said:

Also I don't use the lever to change motion direction, I just turn the sheaths 180 deg, I found this way was better for keeping the stitch tension

That's what I do on most of my machines that lack reverse. I call it Poor Man's Reverse.

[PEU]

2 minutes ago, Wizcrafts said:

That's what I do on most of my machines that lack reverse. I call it Poor Man's Reverse.

LOL In my case it does have reverse, but still didn't figured out how to properly do it and not ruin the stitch, will have to practice more, but in the meantime its 180 turns...!

[ljk]

A sewing machine usually has more than one tensioner, the first is called a pretensioner.  The purpose to create enough tension to keep main tensioner thread uniformally seated.

On front mounted machine with a dial or a lever without reverse you can simply go to zero stitch length and make 4 or 5 stitches to lock stitich.  This is the way embroidery machine does jump stitches and they also drag the top thread to the bottom.  I use this method for leatherwork because appearance is important.  My 44 and 31 old black Singer have a stitch length lever but no reverse, so you simply go to zero and make a few stitches.  You can usually pull top thread through to the bottom and trim. On my 280l has a dial and reverse, for stitch quality I go to zero and lock the stitch  This won't work on 111 and clone machines. Also Singer and Adler shoe patchers. It will work on CLSP.

[dikman]

Interesting arrangement of the various tensioners. It looks to me as if tensioners 2 and 3 are in the wrong positions, I would have expected the final tensioner (#3) to have the two tension discs, as it stands now there is nothing to actually grip the thread and stop it coming off the spool if any slack develops as the takeup arm moves up and down.

[kgg]

@PEU I looked at both video's and see you made mods to the last thread tensioner and added a thread guide to the needle bar. Adding the white guide on the needle bar has changed the angle that the thread enters the eye of the needle and by changing the thread guide just above the last tensioner it also changes the thread angle. Did you have this problem before you made changes??

kgg

 

 

Edited March 10, 2024 by kgg