Cobra 4 backstitch problem

[aaron8771]

Hey all, new to this forum, been browsing it for a few years. Just received my new Cobra 4. Works wonderfully especially compared to the Boss stitcher that I have been using. Except for one problem. When I start sewing, I back up three stitches then I'm on my way. Looks great. The issue is when I'm ending my stitching run, I back stitch 3 and I have a mess on the bottom. This happens every time. I've been practicing using 14 oz and two 8 oz veg tan. Stitches look good, knots appear centered. I'm using 277 bonded nylon with 25 needle.  After looking closer at my back stitches, the bobbin thread is laying flat on the bottom of the leather. I've done about 25 backstitches and none of them have worked out. Like I said, starting out the backstitch is good, only when I'm finishing off my run it does it. Any thoughts? Thanks in advance.

[Brooks125]

I believe you have a tension issue.  When you back stitch, the threads now have 2 threads in the hole, instead of one.  It will take some practice, but I corrected the problem by adjusting the top tension tighter ONLY when I am coming forward by my back stitch.  I have a CB3200, and adjusting the first tension wheel on top does the trick.

[aaron8771]

Thanks. I think I read that on here somewhere and it was on a Cowboy. I just think it's odd when I start, I back up 3 then go forward and it's fine. But at the end I reverse three stitches and that's when it does it. 

[Northmount]

If you reverse at the wrong point in the stitch cycle, you may loose the loop that was being formed.  Try making sure the needle is on it's upstroke (after the hook has caught the loop).

Tom

[aaron8771]

Thanks. Its definitely on the upstroke when I throw it in reverse.

Edited April 15, 2018 by aaron8771

[RockyAussie]

2 hours ago, aaron8771 said:

Hey all, new to this forum, been browsing it for a few years. Just received my new Cobra 4. Works wonderfully especially compared to the Boss stitcher that I have been using. Except for one problem. When I start sewing, I back up three stitches then I'm on my way. Looks great. The issue is when I'm ending my stitching run, I back stitch 3 and I have a mess on the bottom. This happens every time. I've been practicing using 14 oz and two 8 oz veg tan. Stitches look good, knots appear centered. I'm using 277 bonded nylon with 25 needle.  After looking closer at my back stitches, the bobbin thread is laying flat on the bottom of the leather. I've done about 25 backstitches and none of them have worked out. Like I said, starting out the backstitch is good, only when I'm finishing off my run it does it. Any thoughts? Thanks in advance.

What type of 25 needle are you using? A point style I would expect to do that maybe. Tri maybe LR I would not expect. Just a thought.

[CowboyBob]

Are you sure your going around the 2nd tension on the side 1& 1/2x?

[aaron8771]

Second tension is wrapped twice

[brmax]

Ya might give this a try. Letting the needle come up almost out or at least to see the scarf or knowing the scarf is well above the feed dog top. For me this requires real slow stitching at start and the end.

These methods seem to work better for myself. I also think even if a blanket foot is used this shuttle design needs more time or the needle being raised. I mention blanket foot as sometimes the single foot pressure can be adequate but may slip/turn with smaller pieces. This I found needed more of my attention, sometimes another added turn down on the top foot pressure so not to miss the full length of the stitch. 

This slipping may not be as pronounced with a flat bottom foot that doesnt press down directly on the stitch. In anycase I cannot use the reverse on the shuttle hook yet as on my non shuttle flatbeds. No doubt these can be thrown in reverse any time with perfect results. So possibly a bit different learning curve I experience.

 

Good day

Floyd

[aaron8771]

Thanks Floyd, I'll experiment with letting the needle up a little more (when I get time) and let you know.