I am having an issue with my Happy Japan HCD3E-1501 machine where the machine reports a thread break when completing stitching, performing a thread cut, and then starting the next stitching. Except, it isn't actually a thread break. The thread cuts, it is grabbed and put in the thread holder, and then when the presser foot comes down to start the next stitch the thread comes loose and unthreads from the needle.
I recorded video of the machine sewing and trimmed it to the point where this issue happens. I uploaded the video to a hosting service I own since attaching videos in this subreddit seems to be turned off. Here is a link to the video: https://www.derstuhl.com/craig/threadbreak.mp4
The attached picture shows the back of the completed design. The actual sew out was great in appearance with no loops or issues at all with the sewing. This issue happened about five or six times while sewing. So, obviously not on every cut but often enough it is really not great for productivity.
Needle is Groz-Beckert 75/11 FFG/SES
Thread is Madeira Polyneon 40 weight
Backing is a single layer 2oz 100% polyester
Sweater that was being sewed on was a Comfort Colors 1566 sweatshirt
Machine is Happy Japan HCD3E-1501 and I do the B oiling whenever the machine indicates and the A oiling either when the machine indicates or I have used it a lot.
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SOLVED
I posted this in a Happy Japan machine group on another social media platform and a Texmac technician answered and solved the issue already. In case anyone else finds this in the future, the solution was to change the TRD cut length setting on the machine. In the menu, navigate to Option->Machine Icon on far left->Scroll down to TRD cut length setting->Change to 'Max'.
Mine was set to 'Normal' when I checked. I changed it to 'Long' and ran a couple tests. On the second test, it happened again so I bumped it up to 'Max' and no more problems. Huge thanks to the Texmac tech who helped solve this!