Juki LS-341 Issues (Cobra Class 26, Techsew 2750, etc.)

[howlback]

Here are the problems I am having. Each time I try to remedy a problem, another arises:

Juki LS-341 style machine // 8-10oz Leather // 140/22 Needle // #207 bonded nylon thread

• Lockstitch showing on bottom due to tension being set too low
• Up tension = Bottom stitch pulled up into leather but tacking bunches up on bottom 
• Up tension again = Top stitch thread starts breaking just above foot
• Up needle size to 160/23 & Drop Tension a bit = Bottom looks more clean when tacking but top stitch holes are noticeably larger

Edited February 26, 2018 by howlback

[LumpenDoodle2]

No doubt someone with more expertise will be along any moment to help, but to add my tuppence worth, I’d be tempted to back off top and bottom tension, put original needle back, and start adjusting them again.  

[Wizcrafts]

I use a #24 needle when I sew with #207 (210) thread. But, if you only have the 207 on top, a #23 will do. Using the bigger needle makes it easier for the take-up lever to do its thing. This means you can reduce the tensions and still balance the knots. Less top tension usually means less breaking of the thread.

Frankly, I would use #138 thread when sewing 8 ounces of leather. It is strong enough for that thickness and can be sewn with a #22 needle.

As for the appearance of the holes, try using S point needles. Bob Kovar just got some in stock in system 135x16. The typical leather points used in the walking foot system are diamond/triangle point which poke a bigger hole.

[LumpenDoodle2]

See....told you someone would be along.  :-)

[howlback]

Thanks everybody!

[Northmount]

I assume you are hanging onto the threads when starting a line of stitching?

Tom

[howlback]

31 minutes ago, Northmount said:

I assume you are hanging onto the threads when starting a line of stitching?

Tom

Yes.

[howlback]

I was able to successfully/neatly sew/tack 8-10oz leather with #207 thread and a size 23 needle by first backing the primary tension adjustment and reconfiguring the thread path on the top of the machine. This way, the machine will comfortably sew 8-10oz leather with the primary tension adjustment all the way out. Before I tack, I increase the tension using the primary adjustment and the machine pulls the lockstitch up neatly on the bottom side. Don’t know if this normal practice but it’s working until I can get a tech out.

Edited February 26, 2018 by howlback