Mekanic Report post Posted June 7, 2023 "Straight" stitch working with same tension setting as "Reverse". Straight stitch appears normal with topstitch, and bobbin side appears normal. When I perform "Reverse" stitch the (large) thread "twists" into a tiny knot with the bobbin thread making a little "nub" at each reverse stitch. Both threads are "left hand". Juki LU-563 Heavy Leather (0.175) #24 Needle TopStitch Thread (135?) Bobbin (75?) I'm definitely "outta-my-league" here...SmartPhone pics say "Max size exceeded"? Quote Share this post Link to post Share on other sites
Northmount Report post Posted June 7, 2023 47 minutes ago, Mekanic said: I'm definitely "outta-my-league" here...SmartPhone pics say "Max size exceeded"? Moved your post to leather sewing machines where you are more likely to get some help. Resize your photos or set you phone camera to a smaller file size. See this link for some additional suggestions or helps. https://leatherworker.net/forum/topic/15122-how-to-post-pictures-on-lw/?do=findComment&comment=551171 There are lots more helps available on the web. Quote Share this post Link to post Share on other sites
kgg Report post Posted June 7, 2023 32 minutes ago, Mekanic said: Heavy Leather (0.175) I'm going to assume your "Heavy Leather" measurement is in inches so 0.175" is 4.45mm which is about 11.5 oz thick leather. The needle size for V138 (T135) thread should be good for thick/tough leather. However the bobbin thread being 75 which I'm going to assume is T70 which is V69 is the smallest size really for industrial sewing machines. I think some of your problem is your bobbin thread is two sizes smaller and flimsier then the top thread. This I feel is causing / related to your stitching problems. Why are you using a smaller bobbin thread? Normally the bobbin and top thread should be the same size and type of thread (bonded nylon or bonded polyester). The left twist thread is the standard twist direction sold today also known as Z-Twist, or Standard Twist. Mixing thread colors and types of thread can also pose problems as darker threads like black are stiffer then lighter colors like white and bonded nylon is also stiffer then bonded polyester. kgg Quote Share this post Link to post Share on other sites
Mekanic Report post Posted June 7, 2023 I was "gifted" with a JUKI LU-563 (14 years sitting in a barn)...I've SUBSCRIBED to everyone with even remotely "135x17" systems...dumped the "clutch"...750W Servo and Speed Reducer (Toledo Hardware) added. Mechanically...I can fix most things...so far so good. Lot of "Industrial Thread" (for free)....and a can of Sewing Machine Oil since the Juki was "locked up". Been lurking on Leatherworker...and found very helpful information/comments and discussions as a GUEST and eventually a member....From some VERY Technical people! Quote Share this post Link to post Share on other sites
Mekanic Report post Posted June 7, 2023 I suspect my issue is with "using the wrong needle"....135 x17...rather than 135 x16...The option is being mailed this week. Quote Share this post Link to post Share on other sites
AlZilla Report post Posted June 7, 2023 2 hours ago, Mekanic said: Lot of "Industrial Thread" (for free) Get a cone of new thread, too, while you're waiting for the needles to arrive. Your free thread may be fine, but eliminate that variable. Once you have it cooking along, then try the older thread. And follow kgg's advice about top and bottom thread. Quote Share this post Link to post Share on other sites
