This Is To My Fellow Cobra 4 Owners

[Slow Learner]

This is to my fellow Cobra 4 owners. I for the most part like the machine even thought it probably is overkill for what I do. (holsters, belts and odds and ends. But I have a block and can't seem to find a solution. Of course I could call Steve but, I wanted to find out if others have experienced the same thing and if so how you resolved the problem.

The problem is that when sewing around curves (not tight turns at all) or when sewing up a gradual incline to two or three thickness of 8-10 oz. leather the stitch length will become smaller. Sometimes it will happen when sewing a straight seam with no turns. I have about decided the feed dogs (spelling??) are the culprit. My machine came with the smooth surface feed dogs in place so I figured that was appropriate and never thought to changing. It has become very frustrating because every project ends in my quickly growing box of uoops. I can't let anything out of my shop that looks like that. I am about to go back to sewing everything by hand and suffer with the pain or give up completely and sell everything.

HELP.

Darrel.

[RoyalLeatherDesigns]

You are right that does not look good at all I know this would of not happened on a needle and awl machine you get a beautiful tight stich on these machines from what I have seen that is why I purchased one as well. The Cobra Class 4 can produce a good looking stitch as well I don't know what is going on with your Cobra. Before you think of even giving up contact Steve he will do whatever it takes to make it right it might just be user error or something so simpe like changing the presser feet or plate. The point of life is to move forward and not to go back.

Ralph

[Cobra Steve]

Hi Darrel. Put your stitch length at 6 or 7. Also make sure that the feed dog hasn't dropped, it should be no more than 1/16" above the plate at its highest position. Thanks for the kind words, Ralph. Steve

Edited September 17, 2013 by Cobra Steve

[Slow Learner]

Got it working now. Looks good on 5oz. and 1/2" thick. Now on to sew. Thanks Steve for your patients and understanding. It's good knowing you are there we non sewing mechanics run into problems. Darrel

[Cobra Steve]

Thanks, Darrel to you or anyone else that needs me. Steve

[Red Cent]

Steve!!! Steve!!!! I need you!!!!!!!

[Samalan]

Before sewing again make a check list be sure everything is correct ! then do a test run on some scrap of the same size bends and the like. Then take your time if it works on the test piece more than likely it will work on the project. This is the 6P method it works for me hope it will for you 2 . and never give up what the hell would G.S.P> say! your work looks good ! stay with it. hope this helps. I am afflicted with C.R.S. that's why the 6p works for me. Stan

[BigJake]

Slow Learner,

I have the same problem with my C4 machine and it's about the top thread tension. Put about 1/4" of leather in your machine and turn the handwheel very slowly and look closely at the needle/presser foor interaction. You might take off the dust cover off and also watch the thread as the stitch is picked up. When the hook picks up the thread the needle is on the way up and as the hook rotates on around pulling thread through the needle and top thread tensions, observe what happens. The top thread is pulled toward the front of the machine and at the same time the needle is pulled/bent toward the front of the machine along with your product because the needle is still in the product. The high tension will cause the product to slip under the pressor foot, which is effect shortens the stitch length. The thicker the material being sewed, the more top tension, therefore shorter stitches. I also expect that when you are backstitching the needle is not going in the same hole. That's because to compensate for the above issue if you want 6 STI you will need to set the machine for 5 STI. When the lever is reversed there is no p[roduct slipage under the presser foot and therefore you will get 5 STI on the backstitch.

Take a scrap piece of 8oz veg tan and stitch without any thread in the needle. The stitches will be longer than when thread is used. Is there a fix for this, which I'm sure is a top tension issue? I don't know. I do believe that haveing the front of the walking foot or needle foot cut out adds to the problem. When I sew 1/4" of veg tan using 277 thread top and bottom and a 25 needle, the needle will be bent forward completely into the cutout. The other heavy stitchers like the Ferdco and Juki 441 I've seen, don't have this cutout. Just a round hole for the needle to pass through. This round hole would prevent the needle from coming forward nearly as much and I believe would solve much of the problem.

[Slow Learner]

Slow Learner,

I have the same problem with my C4 machine and it's about the top thread tension. Put about 1/4" of leather in your machine and turn the handwheel very slowly and look closely at the needle/presser foor interaction. You might take off the dust cover off and also watch the thread as the stitch is picked up. When the hook picks up the thread the needle is on the way up and as the hook rotates on around pulling thread through the needle and top thread tensions, observe what happens. The top thread is pulled toward the front of the machine and at the same time the needle is pulled/bent toward the front of the machine along with your product because the needle is still in the product. The high tension will cause the product to slip under the pressor foot, which is effect shortens the stitch length. The thicker the material being sewed, the more top tension, therefore shorter stitches. I also expect that when you are backstitching the needle is not going in the same hole. That's because to compensate for the above issue if you want 6 STI you will need to set the machine for 5 STI. When the lever is reversed there is no p[roduct slipage under the presser foot and therefore you will get 5 STI on the backstitch.

Take a scrap piece of 8oz veg tan and stitch without any thread in the needle. The stitches will be longer than when thread is used. Is there a fix for this, which I'm sure is a top tension issue? I don't know. I do believe that haveing the front of the walking foot or needle foot cut out adds to the problem. When I sew 1/4" of veg tan using 277 thread top and bottom and a 25 needle, the needle will be bent forward completely into the cutout. The other heavy stitchers like the Ferdco and Juki 441 I've seen, don't have this cutout. Just a round hole for the needle to pass through. This round hole would prevent the needle from coming forward nearly as much and I believe would solve much of the problem.

Have you talked with Steve about this? They are interesting observations. Since the Cobra 4 is for the most part a "clone" I would expect there to be a reason for difference. I have looked for what you described and sure enough my machine does the same. I can start sewing a single piece with a good stitch and as I sew the stitch will change and start pulling the top stitch all the way through the piece leaving the bobbin thread flat on the back of the piece. I adjust the stitch again and continue sewing then I will get a loose top stitch. The stitch stands up above the others and after I finish I have to pull the bottom of the stitch bringing the top stitch back down then milt the back stitch to take up the slack. I thought it was just me but maybe it's not. I'm going to call or email Steve with this information. Maybe he has some thoughts.Thanks

[BigJake]

Browse the web for the othere 441 clone machines and look at the presser foot for the needle. They will all have a round hole for the needle to pass. This hole would prevent all but the slightest forward movement of the needle which would go a long way to solve the problem. If you use any of the plates that require removing the feed dog such as the holster plate, the problem is compounded. I have checked the timing and all other adjustments and all are good.

Shurely others are having this problem as well.

[GoldenKnight]

Please post the solution when you resolve this issue.

I'm finalizing my research & savings and expect to buy a 441 clone, leaning toward the Cobra Class 4, ... however, for the cost of this investment, it would be reassuring to know this isn't a problem with the machine, but a setting issue of the user/operator.

Thanks.

[Red Cent]

There is a "fix". I struggled with the tension, thread drag, skipped stitches, and flat laying bobbin thread. So I started experimenting. The final result is no tension. Both spring nuts backed off all the way. Just enogh not to vibrate off. I thread through the top eyelet, then over the top tension disc (snap it in) and straight down to the bottom eyelet. Wind counter clock wise 3/4 of the disc and out to the "spring" eyelet and up to the take up arm. The rest as usual.

I adjusted the bobbin tension per instructions from Massive. I changed from nylon to polyester. 277 on top and 207 on bottom with a 24 or 25 needle.

Learning to tie off rather than back up.

Skipped stitches are history. I have no short and long sitches.

Just operator errors.

Price does not include handguns:)

Edited October 6, 2013 by Red Cent

[Red Cent]

End of discussion?

I believe that the Cobra 4 and the others will sew. I believe there are 927 ways to thread these machines to sew. I believe you have to find your combination. Needle, thread, tension, leather, lube,....heck, I have noticed when my thread hangs up on the spool even a little bit, it creates awful tension on the thread at the discs...if you have it threaded as from the factory. Kinda touchy sometimes. I think I have rid myself of most all the touchys.