Marie Juki1508 Report post Posted February 7, 2015 I hope there is a savy machinist how will see this post. I have a new Juki LU1508N. I have been having very slight fraying on my bottom thread so today I checked for burrs on the feed dog, gave a quick swipe with some sand paper and then swabbed around the bobbin case/hook/under throat plate with q tips and then blew in a couple of spots with compressed air. As I was cleaning, I hand wheeled back and forth a bit to get all around the bobbin case with q tips. Now my machine will not make a full rotation!!! I cannot hand wheel the needle down. I can wheel about half way through the rotation- moving forwards there is an extreme friction point and it will not turn any more and likewise moving backwards. I have tried holding down the safety clutch button and to no avail!! All we can figure is that I blew some major lint right into the bottom moving system? Now on the search for proper tiny flat head screw driver to take apart the bobbin case... Any thoughts?? Here's a quick video of hand wheeling back and forth and how the rotation is limited (needle will not go down). Before cleaning the machine, my timing and stitching was all great except for the very slight and intermitant fraying of the bottom thread. http://youtu.be/wI8xcLAVmNc Quote Share this post Link to post Share on other sites
SARK9 Report post Posted February 7, 2015 (edited) With your needle plate off, there is nothing to prevent the entire bobbin case from rotating out of position. There should be a small tab on the front of the bobbin basket that fits in a notch in the underside of your needle plate. -DC Edited February 7, 2015 by SARK9 Quote Share this post Link to post Share on other sites
Marie Juki1508 Report post Posted February 7, 2015 Thanks for your response- yes the video I posted is misleading bc it shows the bobbin case in the wrong position- with it correctly centered within the throat plate notch, the problem is still there Quote Share this post Link to post Share on other sites
Marie Juki1508 Report post Posted February 7, 2015 Here is a better video- you will see that the needle only goes about half way down. I cannot turn the wheel anymore. http://youtu.be/2PfCHy7u8gg Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 7, 2015 Flip the head back on the table, or the support peg if your table has one. Check the gears that drive the hook to see if debris got stuck between the teeth. Quote Share this post Link to post Share on other sites
Marie Juki1508 Report post Posted February 7, 2015 Oh man! Just found the problem!!! A piece of a plastic zipper tooth was jammed way down under the bobbin case, under the brass part that is connected to the bobbin case opening arm/lever. We removed the bobbin case and stared at the whole bobbin assembly for more than an hour with a headlamp on. Wow so much frustration over a tiny trapped plastic zipper tooth... so glad this is over!! Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 7, 2015 Ah yes, the old mislaid Vislon zipper tooth ploy! The Russians used them to sabotage Leica 35mm cameras used by our guys during the Zipper Wars. Quote Share this post Link to post Share on other sites
gottaknow Report post Posted February 7, 2015 Nice job figuring it out! Over the years, the list of things I've removed under a verticle hook include broken needles, dropped throat plate screws, candy, and a diamond out of an operators ring. The only reason I figured that out, was because she pointed to the hook area to show me what was stuck and I noticed the stone missing from her ring. That one I removed very carefully! Regards, Eric Quote Share this post Link to post Share on other sites
Marie Juki1508 Report post Posted February 7, 2015 Thanks everyone! What a relief it was to figure this out- and now know how to check for this next time! Wow, Eric! A diamond!!! Quote Share this post Link to post Share on other sites
catskin Report post Posted February 8, 2015 I like your little blue assistants you better keep them around they look small enough to go in and inspect without much taking apart. HA HA Quote Share this post Link to post Share on other sites
