Cobra 4 Problems

[Ken Nelson]

I have had my cobra for over a year and have tons of broken needles and have never been able to sew a project yet. Steve now says my problem is tension. I have spent hours working on that and no lucka, the last time I talked to him, it sounded like he was fed up talking to me. So the machine is now sitting in a corner with flower pots on it and I am back to hand sewing and guess I will hand sew from now on. The machine is not worth the hassle. Hand sewing sure is faster and better for me.

Regards,

Cajun

Cajun, would you like to sell this machine. Ken

[KND]

Thanks EVERYONE for the suggestions. I have a lot to try, and look into, and so far a few things MAY have made an improvement, but I've not done enough testing yet. I will be sure to come back and explain once I know what worked. And yes, I've been in contact with Steve. So far nothing has worked, and me not living in the US makes it all the more difficult, but I have talked to Steve, and I know we can work it out. I was just trying to get suggestions of other things to try, since so far, advice I have been given has worked for me.

I am threading the machine correctly, as I have been instructed to do, via video & written manual made specifically for the Cobra 4. I've trying to thread it the Cowboy way, but so far that isn't working either, and my thread keeps jumping out of the tensioners! So I guess there is a bit of a difference in the machines. Thanks for pointing out the wheel too, Steve!! My husband and I set the machine up, and we didn't notice! But that hasn't seemed to have hindered the sewing, as the belt wasn't rubbing, but makes me wonder if there is something else we missed.

Wizcraft, your advice and set-by-step have been so great! I've checked through all the points you mentioned, and we've got no thread hang-ups, everything seems to move through each point seamlessly. We did adjust the bobbin spring slightly, to get a tighter fit, and that has made the bobbin thread move through more smoothly, which has no doubt helped as well. I feel like I am close to solving this.

In regards to leather thickness & thread, we may have to switch it up, but from previous projects, we've not have a problem with the needle or thread sizes we've picked here. AND I have sewed both of my leather sizes before, perfectly, on the Cobra 4 (and other machines, without a hitch). It's just the randomness in getting the tension back to be able to sew these projects again, repeatedly. I can't wait to get this worked out, and I am so grateful for all the help so far!

[Wizcrafts]

KND;

Please get some other thread and see if it fixes the problems. Thread can vary, spool to spool, batch to batch, color to color.

[KND]

Threading the machine the way others suggested above has sort of helped. I have done only one loop around the lower tensioner (which has given me the best results) but my results are inconsistent still. Not quite as bad as before, but not good enough. I'll try & post a photo (using an iPhone at the moment & not sure it's possible). I will try using other thread too, but at the moment I only have size 270 (which I use with the #25 needles) & 90, so I might have to order some in & that will be week or so (I live in an area where it's very hard to get industrial sewing supplies and usually always have to order online). I tried using this combo of needle, thread & machine threading on more layers of veg tan, but results are same my lighter sample (even with re-tensioning). So, still stuck, but will keep this thread updated on any progress.

[KND]

Hello!

It seems the issues have been resolved! Of course, it was simpler than I thought it would be, but I also knew it could be done. (Cajun, call Steve!)

I arranged a Skype call with Steve & David from Leather Machine Co. I was able to show them some live webcam images, so they could see exactly what was going on, and what I expected to get from the machine. Steve asked me to re-calibrate the tension discs, which was very simple to do. All I needed to do was loosen the nuts on both tensioners, and then put them back on, just until they were putting pressure on the tension springs. I threaded the machine as usual (the original way I was threading the machine was 100% correct, shown in the video above), with the key to my problem being the needle size. I changed from a #25 to a #24 and began to test sew. Once I found a close enough tension setting, I noticed immediate difference in the look of the stitch. It was already much neater & consistent looking. I kept the same size thread (T270 as I always used with the #25 needles). But I was still getting slight problems with the tension varying between too tight, and too loose, with almost no adjustment to the machine. So, I changed to a #23. This time, any adjustment made an immediate impact, but was consistent. So, if I adjusted too much or little, I could easily see what I had done. It seems my leather thickness has been too thin for the holes I was punching, and therefore, the knots were too easily pulled through the leather (either top or bottom) and any tension adjustment I would make worked for only a few stitches, and then didn't seem to matter anymore. With smaller holes, the knots are more easily held inside the leather. So, though I have sewed with a #25 needle & T270 thread for years on my old machine, with this new machine some of those "rules" weren't working the same way. Here is a photo of the improvement, with top and bottom views of the same stitches. I may decide to try other thread in the future as well.

Steve also mentioned that black thread can be harder to sew with, as usually it has the most amount of dye, therefore making the thread a little stiffer. I first did testing with only black thread, and then went to my contrasting black bobbin, white top thread combo. Both worked great with the same tension settings, though sometimes this might need to be adjusted. Since finding a nice balance, I re-tensioned the machine back and forth a few times to do testing for both styles of sewing I do (#21 needle & T90 thread on thinner chrome tanned layers - approx total 7-14 oz / #23 needle & T270 on 1 layer chrome + 1 layer veg tanned - total 10-11 oz). So far, I have been able to go back and forth, with no problems, which was my original hang-up - not being able to go back and forth quickly between my two tension settings. Also, it's so important to (listen to the video he sends to Cobra customers and) adjust both top tensioners in conjunction with each other, and only adjust no more than 1 full turn at a time. I had done that at one stage, but I am sure in my frustration must have got them off kilter from each other, which wasn't helping my problem!

My bobbin settings have remained the same for both thread thicknesses as well, which also makes for a faster job in setting the tension for both sewing styles. I keep the bobbin spring barely loose, and the tension screw done up all the way.

I am SO happy this has been sorted out, as problems can be so frustrating. Steve was great to talk to, and easy to get a hold of as well. He also called back the next day to check and make sure everything worked out OK, so if not, we could move to step 2. He re-assured me of all the testing they do before the ship a machine out (especially so far, as I am located in Australia), and obviously that is the case. This problem was a USER problem (ME!!!) and not the machine itself. Of course, most new machines will have a slight learning curve, and like my old machine, figuring out they way it likes things is a bit of trial and error. I also want to thank everyone on here for their suggestions. In the past when looking for troubleshooting, it's been extremely helpful. I hope this post has also solved some problems for people.

PS, for those wondering about the machine threading, the reason the thread passes through the guides on the way through the discs, and then on the way out, is because of what I mentioned WAS happening to me when I tried new threading techniques - the thread just jumps out of the discs. The way I threaded the machine originally, and on my video is exactly how the manual & video CobraSteve provide me with shows me to do. Interesting how machines can differ on those small points, yet it makes a HUGE difference in the quality of sewing.

[ChapinLeather]

I've had some of the same problems I haven't worked out everything yet, but I did manage to stop breaking needles and ruining leather. Part of my problem seemed to be the type of leather I was using. I do notice that it works very well on vegetable tanned leather and not as well on naked leathers. It does seem to have a problem with making the stitch look both the same on the top and bottom of the stitch although I've tried adjusting it and tweaking it all over. Part of the problem it seemed was that because I worked with other finishes the leather would be sucked down with the needle and as the project grew it seemed to pull needle around. My solution was to loosen the tension a lot! then gradually tighten (although I still haven't been able to match the top and bottom stitch). I added a box to extend table to lighten the pull of the weight of the leather and I also have used hand stitching in those areas where I seemed to have trouble or hand crank lifting the item to relieve the pull. It isn't a perfect solution and I still am having an industrial machine repairman come in and help me make adjustment, a fix a few things for me, if I get a moment of time to stop working on projects, until then I'm just making it work as best I can.

I can say this however, the machine goes through a lot of leather, with no problem, and after I did all the above it seems to be starting work with the projects I've been doing. To date I've worked with Buffalo Leather, Mellow tan, and Hair on Calf on this machine. I came here looking for a bobbin winder suggestion so guess I'll get back to that.