Sewing Dyed Leather

[IngleGunLeather]

Hello everyone. I've only had my Cobra Class 4 for a few months. One thing I'm having difficulties with is unequal or inconsistant stitch lengths on dyed leather. I have been doing a test run on scraps prior to starting the job on the real deal. On the scraps (undyed) I'll get 6 SPI, and on the dyed I'll get 7 1/2 to 8 SPI sometimes. The undyed scrap leather and the dyed product leather are of equal thickness as well. I'm guessing the dye is hardening the surface of the leather just enough to prevent the feed dog from doing it's job, sorta like it's slipping half way through the feed. What's frustating is that sometimes I'll get 6 SPI and sometimes I'll get 8 SPI on a single line. Has anyone else experienced this? If so, do you have any suggestions?

Edited August 26, 2012 by CountryTrash

[Jimbob]

Hello everyone. I've only had my Cobra Class 4 for a few months. One thing I'm having difficulties with is unequal or inconsistant stitch lengths on dyed leather. I have been doing a test run on scraps prior to starting the job on the real deal. On the scraps (undyed) I'll get 6 SPI, and on the dyed I'll get 7 1/2 to 8 SPI sometimes. The undyed scrap leather and the dyed product leather are of equal thickness as well. I'm guessing the dye is hardening the surface of the leather just enough to prevent the feed dog from doing it's job, sorta like it's slipping half way through the feed. What's frustating is that sometimes I'll get 6 SPI and sometimes I'll get 8 SPI on a single line. Has anyone else experienced this? If so, do you have any suggestions?

Try to make a very long run on a scrap piece ( undyed ) you eventually will see same problem....I dont think dyed leather is a factor in your problem....

veg tanned leather does not get hard enough from dye to cause a slipping factor...but take it with a grain of salt, just my 2 cent's...

hope you find the problem.

james

[Wizcrafts]

1. Tighten down the pressure spring on top of the presser foot to obtain more positive drive.
2. If you received a blanket feed dog (with teeth), try using it with the slick leather.
3. Use the double toe harness foot for more distributed top pressure.
4. Back off the top and bottom tensions (to match), to reduce thread drag.
5. Check the position of the inside and outside feet as the stitch completes, the feeder lowers and the needle ascends. If there is too much free play the leather may be pulled back toward you before the outside foot secures it in place. This is user adjustable with the middle size Metric Allen wrench supplied by the dealer. The large crank on the back that feeds into the faceplate controls the vertical position of the inside foot. (See photo)

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