Joe112 Report post Posted July 31, 2020 I bought a Techsew 2750 Pro less than a year ago and it’s been nothing but problems. After finally reaching tech support I was told this back stitching was acceptable for the machine. None of the backstitching holes are lining up when I put the thread on the machine. Without thread this works just fine. Could someone please help me in fixing this? Quote Share this post Link to post Share on other sites
CastleLeatherWorks Report post Posted July 31, 2020 just $0.02 but the stitching doesn't look horrible. I mean to say that this is unacceptable for a product you would sell.. but to me it looks like operator error or maybe you weren't guiding the leather back properly or you tried going to fast. I don't know your experience level with sewing machines but have you had anyone with more experience than you try to troubleshoot the problem? I do not own a sewing machine btw. just food for thought. Quote Share this post Link to post Share on other sites
Joe112 Report post Posted July 31, 2020 (edited) Thanks for the quick response. I was videotaping the whole process for the Techsew support person. I was holding it probably in the machine. The photo is from the fifth or sixth attempt and it was doing the same thing the whole time. When we removed the thread to ry it that way everything lined up fine. The backstitching holes are closer together than the forward ones. This photograph may be better. Edited July 31, 2020 by Joe112 Quote Share this post Link to post Share on other sites
SolarLeatherMachines Report post Posted July 31, 2020 1 hour ago, Joe112 said: After finally reaching tech support I was told this back stitching was acceptable for the machine. *sigh* No, it's not. This is a common problem with the Juki 1341 style of machines. The back stitch should be adjusted to very closely match the forward stitch. The problem is that most techs don't now how to do it. Some will actually say it CAN'T be done. But it can. You have to get under the the head, and carefully adjust the rocker assembly. It's a painstaking process, and you have to know exactly what you're doing. Regarding thread in vs thread out, well, that's not much help, since you'll almost never use the machine with the thread out. The machine should be adjusted so that it sew correctly backwards WITH thread, otherwise it's pointless. I would add that it seems you're using a pretty severely mismatched thread & needle combo. I don't know what size that you're using but the 1341 clones usually sew upholstery grade leathers best when you run 1 needle size down. Quote Share this post Link to post Share on other sites
Techsew Ron Report post Posted July 31, 2020 Hi Joseph, no it is certainly not acceptable. According to our technician you had mentioned the problem was resolved a few days ago. What thread size/needle size are you using? Have you tried with any other sizes? We'll be giving you a call to go over some further adjustments and technique with you. Ron Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted July 31, 2020 This is but a free hint. Loosen the top and bottom tensions somewhat, then balance the knots to land in the middle. Try your test stitching again and see if the lower tension helps to get equal forward and backward stitch lengths. If so, you've saved a major headache with under body adjustments. Mind you, those still might be necessary if the thread lies too loosely. Quote Share this post Link to post Share on other sites
Arturomex Report post Posted July 31, 2020 5 hours ago, SolarLeatherMachines said: ...but the 1341 clones usually sew upholstery grade leathers best when you run 1 needle size down. Not looking to jack this thread but what does "run 1 needle size down" mean? Quote Share this post Link to post Share on other sites
Frodo Report post Posted July 31, 2020 1 hour ago, Arturomex said: Not looking to jack this thread but what does "run 1 needle size down" mean? I could be wrong, but I believe he means 1 needle size smaller than you are using Quote Share this post Link to post Share on other sites
Arturomex Report post Posted July 31, 2020 Hey, thanks, Frodo. Quote Share this post Link to post Share on other sites
RockyAussie Report post Posted August 1, 2020 Just an observation......Your top tension looks to be too tight. When either the bobbin or top tension is too tight on supple type leathers you will often get a stitch length variation which can be worse when the machine does a reverse stitch. Firstly I would check that you can stitch through this leather in a continuous run and get the tensions showing up in a similar way, meaning no going up and down on and off. If you have it right there will be no shortening of the leather length from what it was to start with.(alittle longer perhaps) Back your foot pressure off until you can raise it by lifting the foot with your hand. I generally set my foot pressure back until the job wants to lift with the needle then screw it down a couple of turns. (you may have to consider taking out the small spring inside if you have not already) The needle size you are using is too large a size for this leather with this thread. Also that thread looks a bit like a slippery type thread and it may be worth trying another type to help rule that out as 1 potential problem. (they can be difficult to get the tension right sometimes on slippery threads). Try a firmer leather and see if that works and if the stitch does not return back into the same holes THEN start looking into under machine adjustments. Quote Share this post Link to post Share on other sites
SolarLeatherMachines Report post Posted August 1, 2020 12 hours ago, Arturomex said: Not looking to jack this thread but what does "run 1 needle size down" mean? It generally means to use 1 size down from the nominal needle size. For example, a 441 clone sewing a size 138 thread would normally use a 160/23 needle. But on a 1341 clone, it would sew better with a 140/22 needle. Quote Share this post Link to post Share on other sites
Arturomex Report post Posted August 2, 2020 14 hours ago, SolarLeatherMachines said: It generally means to use 1 size down from the nominal needle size. For example, a 441 clone sewing a size 138 thread would normally use a 160/23 needle. But on a 1341 clone, it would sew better with a 140/22 needle. Thanks! Quote Share this post Link to post Share on other sites
Gregg From Keystone Sewing Report post Posted August 4, 2020 Make sure that when you go into reverse that the needle is down, this is commonly done with ornamental stitching to ensure that the stitches appear the same front to back. Quote Share this post Link to post Share on other sites