Cobra 4 thread tension

[Red Cent]

I am watching for the umpteenth time the John Bianchi videos. Yeah Slowhand Bob, I finally got my own.

I am aware he is using a Ferdco. The Cobra 4 is a copy right? Well, watching the video of him sewing the holster and it hit me. When he quits sewing, he raises the foot and pulls the holster and unwinds thread. HUH!!??

You Cobra 4 owners. I know it tells you not to do that or you might break a needle. Shoot, I have small thread cuts in the wrinkles of my fingers trying to pull thread out.

If you watch it, it does not show his hands. But. The thread arm is all the way down and he couldn't grab it anywhere. He does it a couple of times and you can tell he is not using the hand to free up thread.

What gives?

[Massive]

The tension on my cobra as per factory (still haven't got my promised stuff from when I bought it), is fine, but it is set really heavy.  With my GB6-180, I got excellent results with a lot less tension, and I could pull the thread out without doing anything other than moving the piece away.  That machine had an enclosed foot, so long as the needle was all the way up, and you pulled in the right direction, you could just pull thread out.  It's threading route was completely different, and not as optimal, for one thing one could get loop snags pretty easily if one didn't check the path every time.  The Cobra is better, but my point is that the thread path is not always the same on all these "copies"

In one of the two youtube videos, the method shown to get the holster out of there is to raise foot, come over top dead center to the release point, then I reach over with my right hand, and at the point you should be at, the thread take up lever is nearly at the top.  You grab the thread with your thumb down just below the take up lever, and pull down quite a way about to the next guide.  Depending on how much thread I need to release, I may need to do that several times.  Then one pulls the pieces back at about 8 oclock, and it comes easily as all it is doing is pulling out the bobbin tension.

If you are really having trouble, you should remove the bobbin cover and check to be sure the loop is off the hook.  Presumably it is, but just be sure that you are free and clear, or it will be near impossible.  I think you can't have the loop stuck when you take the piece out or the needle would be down.  But you will see situations where people clear the machine, and do a few things they think will help, and before you know it, the machine is in lock down.  It is like shooting, maybe moreso, there is a right way to do stuff, and if you are doing it wrong a) you will be shooting yourself in the foot, and it should be obvious; b) and when doing it right, you will be grooved and doing everything the exact same way every time.

Check the Cobra, and the other long video, skip to any sewing sections, and watch exactly what they do, and do it exactly that way.  Bianchi tape is excellent, but the sewing sections don't translate that well for a bunch of reasons.

[Cliff Fendley]

As Massive said. pull thread from the take up arm. When you raise the presser foot all the way the tension the thread should be released.

[Red Cent]

The factory setting was very tight. The Wiz at Leatherworker.net said he does this: he loosens the left side adjustment until it is barely creating tension. He does the top the same way tightening it as you sew until you make a good lockstitch.

I have been getting skip stitches but the remedy was to make sure you have an unfettered path for the thread. Long story. I did what Wiz suggested and finished sewing a belt with no problems. I am using a #25 needle with 277 top and bottom.

Cliff, I free up thread as you suggested. The factory setting was so heavy that if you didn't hold tight to the thread, it would cut you. Got the scars. I still free the thread that way but is so much easier now.

I did put a lube pot on the machine. I use liquid saddle soap that contains glycerin. The Cobra is sewing great, maybe a combination of all three, but I will take it.

[Red Cent]

I just came from the workshop. Completed a concealed carry holster and the Cobra 4 performed beautifully. Happy camper.

[Massive]

Somewhere along the line, maybe your tension settings got pouched.  Mine sewed great out of the box.  If you got a Monday Morning adjustment, you could end up in a world of hurt.  The only upside is you carry this knowledge with you for ever.  I was teaching one of my daughters how to sew here dress the other day, and I really sounded like I knew what I was talking about. 

[outrider]

Red Cent...try using 277 top thread and 207 bobbin thread with a 200 (#25) needle..this is what was recommended by Ferdco when I bought my machine...I have used this for years and have never had any problems.  Even though they have closed their business the ferdco website is still up...go to that site and go into the needle and thread section  and copy down the sizing charts they have.  The Ferdco Pro-2000 is the same machine as the Cobra Class 4 except for a few differences.

[Red Cent]

Thanks Outrider, I will go and copy.

What will happen or how does it enhance the sewing with the 207 thread?

[Massive]

You can get longer runs between bobbin changes.  Should be able to use a slightly lighter needle, but I don't worry too much about hole size, it will always be what the market expects.  We got a list of reasons to use it under and over, but I couldn't find it.  My main concern is that I don't see the big houses doing it that way.  If I pick up a Bianchi or something there aren't two thread sizes, and hand work is done with one thread size.  Just my 2 cents worth.

[outrider]

Thereason is that the smaller bobbin thread will be pulled further into the 200 size hole for a nicer looking bottom stitch.  Massive I think most of the big houses use needle and awl machines as opposed to single needle machines...I guess it is a matter of preference   but I have found that using the smaller thread on the bottom makes a really nice stitch with no bunching.

[Massive]

I haven't dissected my stitch yet by cutting open any scraps.  The top tension on the Cobra is pretty fierce so I imagine it pulls the thread in there.  But the bottom doesn't look that great until one hand finishes it, because the needle is pushing the leather out.  That is partially a needle plate issue, and I haven't messed with that either.

[outrider]

It also may be caused by the type of needle point your using.   I use "spear point" leather needles...for example the ones they sell at Tandy are round point needles and do push out the leather.   The spear point is very similar to the point of an awl...kind of diamond shaped.  If you go directly to the Schmetz Needle site you can see the different types of points that are available

[Red Cent]

Sewed a holster today. 8-9 on the outside and 4-5 on the inside. Cut, glued, sewed, trimmed, and put it together. Ooopppssss. At the barrel portion of the holster the top thread became a straight line apparently pulling up the bottom thread when I folded it and completed sewn it together. 

Are the stitches not tight enough?

[Massive]

Thanks Outrider, that could be part of it.  I got needles like that for a smaller machine I use for 69 thread, and it really helped.  You would think, Bianchi dream machine and all that that Cobra would ship the right needles...  Not saying they don't, but I don't think they are diamond type.  There must be a reason for all the different types.  I think bullets are less likely to weaken the leather, don't know.  Needle awl machines seem to work...

[Massive]

Sewed a holster today. 8-9 on the outside and 4-5 on the inside. Cut, glued, sewed, trimmed, and put it together. Ooopppssss. At the barrel portion of the holster the top thread became a straight line apparently pulling up the bottom thread when I folded it and completed sewn it together. 

Are the stitches not tight enough?

One way what you describe can happen is that the thread runs out in the lower bobbin, then the thread will not be under tension, though it will come to an end right quick.  Though if you hit it just right, what you described could happen.  Normally you can remove the thread and sew it up again, and the threads will go right into the same hole.  I would not want to do that on a holster I was selling on the main seam.  I have restarted a seam where I am just supporting the glue in a lamination and there are no other loads.  Normally you can`t see the restart unless you know what to look for.  A mainseam restart would probably be fine if you were making a prototype for your own use.

Or:

As you may recall I went to considerable lengths to quantify the actual bobbin tension that my Cobra shipped with, so that you could reproduce it.  However, that may or not help you if say the bobbin tension was achieved through a different interface of parts, still worth a try.

What you describe is relative excessive top tension.  Of course one can't tell if the top tension is excessive in absolute terms without knowing what the bobbin tension is, which is why I set out to quantify it for you.  Of course there could be clues like massive leather distortion, or cutting.

Good luck! The adventure continues...

[Red Cent]

Didn't run out of bobbin thread and I believe that the thread was not that way when I finished sewing. And, yup, I have done the redo a stitch line in the middle and, if you are very careful, it is difficult to notice.