BallisticTip Report post Posted March 20, 2015 My machine has been sewing like a dream up until recently after a bad jam. The stitches look decent on top, but if I reverse or speed up the underside looks braided. I cleaned out under the bobbin carrier, changed and adjusted the needle. Could it be out of time? Any ideas? Quote Share this post Link to post Share on other sites
Hockeymender Report post Posted March 20, 2015 For a start, I would check the tension on both the upper and lower threads. Then I would look at the hook timing. I've had issues like that before, and it was usually a tension problem but as stated the jam could have pulled the hook out of time. Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted March 20, 2015 I've tried adjusting the tensions, but I don't think it's the problem - the stiching looks like there's something going on instead of the normal loop stitching. Are you familiar with the procedure for adjusting the hook timing? Quote Share this post Link to post Share on other sites
TRHLeather Report post Posted March 27, 2015 I just finished rebuilding a 1245. Mine did the same when i did not have enough tension on the top thread. It looks like your top thread isn't pulling back up through the hole and the extra loops on the bottom are getting caught up in the following stitches. Easiest way to check this is to sew 3 or 4 inches, cut your threads and see if you can pull the bottom thread out easily. I would recommend playing with the tension before you get into adjusting timing. Timing for the 1245 - 2mm above bottom dead center, the hook should be at needle center (width) and the tip of the hook should be 0.8 - 1.0 mm above the hook point. You can adjust this by loosing the gear that controls the hook rotation. I would recommend looking up the service manual for the 1245 online. Page 12 and 13 will show you all the necessary steps. After extensive online reading, some people have a different take on that but I set mine up to the specs in the manual and it works well for me. My understanding is the 145, 545 and 1245 are mechanically the same in this regard. Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted March 27, 2015 Thanks for the info! I had went through and set everything by the 1245 manual and still had trouble. Thinking I still had something slightly off by being a different model, I had a tech come out but he couldn't fix it either. I'll go through the 1245 manual once more and double check everything. Quote Share this post Link to post Share on other sites
TRHLeather Report post Posted March 27, 2015 Good luck. I had to set mine up many times before I got everything correct. Now it seems to work great. Be patient and good luck! Quote Share this post Link to post Share on other sites
Darren Brosowski Report post Posted March 28, 2015 Hard to tell but think that there is no top tension. Grab the thread to the left of the needle - it should be hard to pull through with the foot down on the work. Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted March 31, 2015 Problem found!! Now how to solve? All of you were right - I set up the machine again and have it sewing decent through upholstery and single webbing, but is still jamming on 3 layers of scuba webbing. It appears the takeup lever is running out of upstroke before the top thread can be pulled all the way and released from the bobbin carrier and hook. So then the hook still has the first loop of top thread as it's going for another round and it snowballs from there... Quote Share this post Link to post Share on other sites
Beardedbandana Report post Posted April 2, 2015 Problem found!! Now how to solve? All of you were right - I set up the machine again and have it sewing decent through upholstery and single webbing, but is still jamming on 3 layers of scuba webbing. It appears the takeup lever is running out of upstroke before the top thread can be pulled all the way and released from the bobbin carrier and hook. So then the hook still has the first loop of top thread as it's going for another round and it snowballs from there... @BallisticTip I'm having the same issue on my Juki Lu-563. Did you find the fix?? Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted April 5, 2015 I haven't had a chance to work on it yet, preparing for the holiday. Hopefully in the next day or so. I'm going to go through all the adjustments again... I've found there are some manuals that are more detailed than others - different (updated?) factory manuals for the same machine. Quote Share this post Link to post Share on other sites
BallisticTip Report post Posted April 12, 2015 (edited) The tension assembly and timing was the culprit. Thanks for the help everyone! Edited April 13, 2015 by BallisticTip Quote Share this post Link to post Share on other sites
Beardedbandana Report post Posted April 14, 2015 I haven't had a chance to work on it yet, preparing for the holiday. Hopefully in the next day or so. I'm going to go through all the adjustments again... I've found there are some manuals that are more detailed than others - different (updated?) factory manuals for the same machine. So I ended up finding my main problem. I didn't have my bobbin housing set right. When you take off the base plate (plate under presser foot) it has a notch to hold a little arm on top of the bobbin case. My bobbin case used to move and spin, now its held in place by that little arm. That's what fixed it for me. Quote Share this post Link to post Share on other sites
TRHLeather Report post Posted April 15, 2015 I had a similar problem except mine was because the clearance between the bobbin case and that plate was too close. The dimensions were not exactly the same because I ordered the Ebay/chineese part instead of the Pfaff part (almost $200 cheaper). It used to tie the most incredible giant balls of thread. I actually had to lower the whole assembly by making shims to get the clearance. I'm glad you finally figured it all out. Good luck sewing! Quote Share this post Link to post Share on other sites