Hi all,
Thanks to all you industrial sewing machine posters for all the advice I've benefited from. This is my 2nd post....because I am absolutely stumped and no amount of searching has helped me figure out what the heck happened.
I'll give you the simple facts first- I'm using 138 thread, #22 needle, sewing leather usually, within thickness range of 3/8 inch, machine sews well, with the occasional tweaking of tension for some seams. It's a KOBE LS 1341, looks just like TECHSEW 2750, Juki LS 1341.
Problem: I sewed a rip in a horse blanket recently. That involved the thickness of the blanket plus webbing folded over the fabric edge. The total thickness may have exceeded the 3/8 inch the machine is speced for, but not by much. The machine sewed the horse blanket seam ok. A bit of top thread tension tweaking was required but I got the job done. I was cleaning the bobbin area afterwards with compressed air, (the blanket was pretty dusty), pulled the bobbin, then returned it, making sure I got all the dust out. Once cleaned, I turned the handwheel and it was stuck, wouldn't turn. Nothing had been changed since sewing, other than cleaning. I checked the bobbin, pulled thread from bobbin and pulled thread through needle just to make sure it wasn't a source of snag. No issues with resistance. Pulled the throat plate and bobbin case to check for thread debris . Found nothing. Checked the handwheel, and it turned freely......odd. So while putting the throat plate back on I noticed that onced I tightened the throat plate screws, the hand wheel was stuck again. I reloosened the throat plate screws and again the hand wheel turned. Retightening the throat plate screws I checked the feed dog clearance and the tighter I made those screws the less clearance there was between the inner side (right side) of the feed dog and the hole in the throat plate. The feed dog was not bent, nothing was visibly loose.....I couldn't find anything to explain why the feed dog now touched the throat plate. Stumped. Please help.....