Singer 111W155 Timing/thread Issues

[gottaknow]

Backlashing in the bobbin case is a fact of life. Over the years, there have been many remedies, some that work better than others.  If you're sewing a long run at higher speed, simply slowing down a bit before  you stop will allow the backlash to be taken up before stopping. The original backlash prevention for Singers was a very thin piece of fabric inserted underneath the bobbin and one drop of oil applied to this as needed. Cohesion did a very nice job of stopping the backlash. I still do this in the factory for older machines that don't have a backlash device in the case. The new (and older Juki's) use a spring device that applies friction to the bobbin. Their double needles use a coiled spring that pushes out against the bobbin to stop backlash. If you choose the fabric method, just make sure that it's thin enough not to increase the tension after inserted. Trust me, high speed garment machines will backlash 12" or so if no steps are taken at all. A huge mess ensues. Even a single drop of oil under the bobbin will decrease backlash. I also use aluminum bobbins whenever possible. The difference in weight makes a real difference.

Regards, Eric

[dmar836]

Thanks Eric.  It's not really the bobbin itself that backlashes - though I'm sure that's the correct term that and that I used it incorrectly. It's the whole machine. There is a slight "relaxing" when I stop sewing, even if using the balance wheel by hand, that occurs only at the point that the needle bar is rising and as the top thread loop on the hook is anywhere between about the 10 - 2 o'clock position. It relaxes just a few degrees essentially reversing.  Not only can you see the hook move backwards but you can see the rising needle bar reverse directions and go back down for 1/16" to 1/8". The forward pressure is relaxed and that's when lower thread of the loop falls under the hook, snags on the hook body(or falls underneath).  While it occurs only at a certain place in the hook formation, attempting to bring the needle up by hand to end a stitch run inevitably means you will wheel past this strange point. It gets you about every time and the only fix I have found is to pass the balance wheel between two hands and never let it go until the needle is up and that stick locked.  Not an acceptable fix IMO. It's subtle as there isn't much movement. I have seen people freely manipulate the hand wheel as I can on my other machines without losing the loop and breaking the thread. 

After starting over so many times with timing, etc. I thought maybe even the belt might have taken a set or that the feed dog was maybe meeting the vibrating foot too soon, etc. Removal of the belt should have stopped either of these but it didn't. There is a stickiness when I manually force the presser bar up.  It's not smooth at all and won't return fully to the needle plate without considerable spring presser added. The needle bar wasn't perfectly straight but doesn't stick in the bore like the presser bar.  Wondering if during a previous transport it didn't fall over onto something that hit the presser bar area. I assume that bar should move smoothly up and down with the flat pressure spring backed off.  I think the PO sold this due to this frustrating issue. 

Thought we had this one licked, no?

Dave

[gottaknow]

Are you using a clutch motor or a servo?

Regards, Eric

[dmar836]

Clutch.  But remember it happens even when disconnected drive belt and cogged belt between shafts. Mystery!

[brmax]

Does it happen when checking with the presser feet in raised position.

 

good day 

Floyd

[dmar836]

Yes.  Just as bad. 

Dave

[gottaknow]

If the machine is sewing ok for you, heel back on the pedal to apply the brake whenever you stop. This is a basic function of a clutch motor. I have a Juki LU 562 that does the same thing. Not really worth my time to find exactly why, but I've seen this on several machines over the years. The large cam that drives the needle bar will sometimes just rotate down due to its weight. Especially on a machine that is well worn and well lubricated. If your brake is set correctly, you should be able to stop the rotation of the machine. When I use a clutch, I always heel back to stop the machine. If the machine wants to creep a bit, it simply can't. Even if you've got some bent bars, if the machine is sewing ok, no worries. 

Regards, Eric 

[dmar836]

Sounds good.  I've never attempted to brake with the pedal.  Thanks a lot all!

Dave

[keithski122]

I had the same problem with a juki 563 I adjusted the brake so as soon as the pedal is released the brake is applied and stops the machine going backwards slightly.It worked really well until I changed over to a servo motor a few weeks ago.

[Cbruce32]

Hello to any who might be able to help. I have a 111w153 and it sews really tight stitches going straight. Very even and right. I have done a lot of adjusting on the machine and finally got it to sew well. The only problem I have is when I am sewing around the end of a belt or making a tight corner the top thread won't pull the bottom thread all the way center leaving a bit of the loop on the bottom of the garment. As soon as I straighten out stitches are tight again. Curious if anyone knew why this was happening. Thought maybe there is a take up timing issue but not quite sure. The loop is more like a wart or a knot. Have a servo motor and speed reducer on the machine. 

Edited April 7, 2017 by Cbruce32