Christoffer Report post Posted April 6, 2015 (edited) I've been sewing a lot, but only on others machines (industrial walkingfoots as well). I picked up a Brother LS2-B837 the other day and changed from a thin cotton thread to a tkt 20 (tex 150) nylon thread. It had a 130 needle, which would be about right accordingly to the thread brand (120-140). Seams to do well on the slide test. (Tried 120 and 140 as well) At first I tried with original thread tension, but it broke the thread. I losened both top and bottom tension a little, the bottom so that the bobbin doesnt slide down holding it in the thread, but loose enough to slide a bit with a gentle "jojo move". I would say its on the looser end now. The top tension I did loosen a lot, because the thread did not move at all, to a point where it falls off from the tension wheels. By the moment it will curl the top thread, and do a lot of birdnesting. Ive tried all day, with my limited error searchings skills, and I'm not even close to make one normal stitch, feels like a needle in a haystack! Edited April 6, 2015 by Christoffer Quote Share this post Link to post Share on other sites
gottaknow Report post Posted April 7, 2015 On both the upper thread guide and the one just before the tension disk, I would only wrap the thread through the first and last holes, skipping the middle holes. That will allow you to increase the top tension and set your stitch, it's simply too loose. Make sure after you've pulled up the bobbin thread that you pull on it and make sure it didn't get tighter. Another cause of this with bonded nylon is that if you're hook timing is retarded some, The previous loop won't get pulled up all the way before the hook comes around and breaks it. Remember, a hook makes two revolutions for each stitch. The first is to pick up the loop, the second is to feed the material. If you know how, I'd also check the latch opener adjustment. If you search this forum, I go into great detail on how to check it. Good luck! Regards, Eric Quote Share this post Link to post Share on other sites
cdthayer Report post Posted April 7, 2015 ...and make sure that your bobbin is not over-loaded with thread, binding the bobbin feed.CD in Oklahoma Quote Share this post Link to post Share on other sites
Colt W Knight Report post Posted April 7, 2015 I have had problems with certain black thread not performing well in my machine. Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 8, 2015 Now I skipped the middle thread guide hole. Yes, the thread pulls out fine after installing the bobbin as well. No, its about 3/4 full, thanks. It does not longer twist the top thread, how ever it tears a bit sometimes in the needle. Most of the times exactly nothing happens Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 8, 2015 (edited) Still cant gett it to work. Trying the bigger needle (160/23) Edited April 8, 2015 by Christoffer Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 8, 2015 It starts allready after two stitches, higher tension doesnt make a differance, I can higher it untill it wont move, no differance Quote Share this post Link to post Share on other sites
dirtclod Report post Posted April 8, 2015 Have you tried a new needle and a different spool of thread ? I had a spool thread that i just couldn't use. It would fray or break when i tried to use it. Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 8, 2015 I tried 2 of each from 120-160. I also rewind the bobin a couple of times. Of this size I only tried this thred yes, it worked fine with the much finer cotton thread. Quote Share this post Link to post Share on other sites
gottaknow Report post Posted April 9, 2015 You should check your latch opener adjustment. It would explain why it worked better with thinner thread. Regards, Eric Quote Share this post Link to post Share on other sites
msdeluca Report post Posted April 9, 2015 Is there a hole near the bottom of the needle bar just above the needle that you didn.t thread? I missed that once and got breaking thread and nests. It was like the machine had lost its mind for no reason. Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 9, 2015 Ok, never done that before. Is it the same as hook timing? Cant find info about it Quote Share this post Link to post Share on other sites
gottaknow Report post Posted April 9, 2015 The latch opener is a little piece that pulls the bobbin basket a bit counter-clockwise to allow the needle thread to pass between the small tab one the basket and the notch on the bottom of the throat plate. It can be checked with material in the machine, with the hook plate open so you can see the needle thread move over the top of the hook. If you search this forum, I go into the adjustment in great detail. I'm attaching a photo so you can identify the part and it's function. Regards, Eric Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 9, 2015 At the further right position the latche is closed, but the thread are no way close to pass at that point anyway. Apparently my hook grabs thread after thread, turning the machine by hand. The safety mechanism deployed earlier as you know. Could the timing belt be wrong? The walking foot and feed dog move perfectly in sync, but maybe they allways move together even if the bobin doesnt spin? The timing marks are correct accoring to manual Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 9, 2015 Oh, the drive belt was wrong, doh... It have multiple timing marks and the availabe manual say different. But this still happens: Quote Share this post Link to post Share on other sites
gottaknow Report post Posted April 10, 2015 I can tell by looking that your latch opener isn't set correctly. Loosen the screw and move that flat curved piece to the right. When the thread approaches the tab on the basket, your latch opener should be contacting the basket to make room for the thread to pass and set the stitch. Regards, Eric Quote Share this post Link to post Share on other sites
Christoffer Report post Posted April 10, 2015 The drive belt was set for the wrong timing mark, it now works. But as showed in the last two pics, this still happen with the thread close to the tensioner Quote Share this post Link to post Share on other sites
Cobra Steve Report post Posted April 10, 2015 Eric's right. Also check the finger on the basket that fits in the cutout under the needle plate. Sometimes you have to take a shade off the cutout to allow heavier thread to pass through. Keep in mind that you should only use 138 top and bottom for maximum efficiency. Thanks, Steve Quote Share this post Link to post Share on other sites
Mel07971 Report post Posted October 27, 2016 (edited) Hi I'm having similar issues with my brother ls2-b837 the bottom tension is all loose has anyone found the full manual online I can only find a blurry copy, I'd like images of how to thread the machine properly as I'm sure that's the cause of the problem?!! Here's an image of the underside of the fabric if you pull the thread it will unravel and slide right out thanks Mel Edited October 27, 2016 by Mel07971 Quote Share this post Link to post Share on other sites
Zambezi Report post Posted February 15, 2017 On 4/6/2015 at 9:10 PM, Christoffer said: I've been sewing a lot, but only on others machines (industrial walkingfoots as well). I picked up a Brother LS2-B837 the other day and changed from a thin cotton thread to a tkt 20 (tex 150) nylon thread. It had a 130 needle, which would be about right accordingly to the thread brand (120-140). Seams to do well on the slide test. (Tried 120 and 140 as well) At first I tried with original thread tension, but it broke the thread. I losened both top and bottom tension a little, the bottom so that the bobbin doesnt slide down holding it in the thread, but loose enough to slide a bit with a gentle "jojo move". I would say its on the looser end now. The top tension I did loosen a lot, because the thread did not move at all, to a point where it falls off from the tension wheels. By the moment it will curl the top thread, and do a lot of birdnesting. Ive tried all day, with my limited error searchings skills, and I'm not even close to make one normal stitch, feels like a needle in a haystack! On 4/6/2015 at 9:10 PM, Christoffer said: I've been sewing a lot, but only on others machines (industrial walkingfoots as well). I picked up a Brother LS2-B837 the other day and changed from a thin cotton thread to a tkt 20 (tex 150) nylon thread. It had a 130 needle, which would be about right accordingly to the thread brand (120-140). Seams to do well on the slide test. (Tried 120 and 140 as well) At first I tried with original thread tension, but it broke the thread. I losened both top and bottom tension a little, the bottom so that the bobbin doesnt slide down holding it in the thread, but loose enough to slide a bit with a gentle "jojo move". I would say its on the looser end now. The top tension I did loosen a lot, because the thread did not move at all, to a point where it falls off from the tension wheels. By the moment it will curl the top thread, and do a lot of birdnesting. Ive tried all day, with my limited error searchings skills, and I'm not even close to make one normal stitch, feels like a needle in a haystack! Quote Share this post Link to post Share on other sites
Zambezi Report post Posted February 15, 2017 Hi, I have had the same problem and believe it to be the needle getting too hot and melting the artificial thread. I have always just increase the size of the needle and the problem has stopped. But I will certainly look at the things I've learnt above. Quote Share this post Link to post Share on other sites
brmax Report post Posted February 15, 2017 Looks like the thread at the check spring is not correct on the last try, and maybe the spring is set to high also. This may have happened on the last break. I would turn it by hand several / many stitches as it looks a bit like the typical not holding top thread back at startup, even though experienced operator. Floyd Quote Share this post Link to post Share on other sites
