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.

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.

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!

I did some more sewing tests, and back to the same tension problems. I guess the shaft made no real difference (but at least that is one less thing to worry about now)

the wheel had come loose on the shaft, so I have just tightened that and are doing more tests now

I did a few tests, taking out one variable each time, and it appears to be the top thread that is causing the machine to stick (whilst the wheel is still tuning) ...

thanks, Im just checking that now

Thanks so much Wizcrafts for your super detailed and helpful response! I am thinking that there may be something other than basic tension issues going on so rather than hijacking this thread I thought I would start another here http://leatherworker.net/forum/index.php?showtopic=37202

I am having mega problems getting proper tension my Cobra 4. It's been months of hours, trying and giving up. Going back to hand sewing and my old crappy flatbed machine. But I am thinking it might be more than just tension. There are times when I am able to wheel the machine by hand, so, the wheel IS turning, but the rest of the machine doesn't move. Ie, the needle (and everything else) stays put, near the top of it's rotation. Im wondering if this may be effecting the tension some how, maybe if something has come loose ? Im really at a loss... http://www.youtube.com/watch?v=y8rBZfq29_E (I posted about the tension problem yesterday, under a different user name, but thought I should instead start a new thread because it does seem to be more than just a tension issue and I didn't want to hijack that thread. I also for some reason wasn't able to sign in under my old name, so I had to make a new account) Here are the tension issues: I finally got it tensioned for one type of sewing I do, took DETAILED notes of the tension settings, then went back to try and tension the other way I sew, and it took hours and hours. Then I need to go back to the first way I sew, and my notes don't work. I can't get it tensioned back to the way it originally was. Am I missing something? It's wasting so much of my time, and a lot of materials. I've asked Steve, but his feedback hasnt seemed to have helped. I am hoping someone else with a Cobra or 441 clone can offer me some tips? The first type of sewing I do is one layer of veg tanned about 6-7oz to one layer of chrome tan 3.5 oz. I use a 25 needle, with appropriate thread. The second type of sewing I do is min 2 layers of chrome tanned, to max about 4-5 layers. I use a 21 or 22 needle, with appropriate thread. I have got the machine to flawlessly sew both, eventually. But every time I try and tension for the other type of sewing, it takes me hours, days. Or longer. Or I give up (and thank God my old crappy machine still works well enough!) In these photo examples, you can see how it varies between top tension is too strong, and then too loose. I CANNOT find the balance. (and yes, the top & bottom thread are the same thickeness & brand). It seems I cannot make a small enough adjustment, so it goes between too little and too much tension immediately. Sometimes I can get it to sew normal for 5-6 stitches, but then it always reverts to one way or the other (top is too loose or too tight) I have adjusted bobbin tension as well. It seemed to like being just off the tightest setting for the thicker sewing, and as tight as possible for the thinner sewing. But so far its made no difference.. http://img824.images...69/tensionp.jpg