Problem with a Singer 112W139 Thread Controller

[tmitch]

I recently purchased a used Singer double needle 112W139.  I have a manual for the machine and have timed it successfully, I believe, but have a few problems I can't seem to solve.  First I can't get the thread controller to work properly.  No matter how I adjust it, it leaves too much slack.  I have moved the stop as low as it will go and turned the controller back and forth for tension.
Too much and it will not let the spring move to the top and too little and it not return to the bottom, and at the best compromise it leaves so much slack that the thread sometimes actually come out of the lowest guide just above the needle.  I have alternately thread it by the manual, and tried some of the "right way to thread a  double needle machine" found on the internet. Nothing seems to help.  I also have trouble with picking up the bobbin thread, but until I solve the slack in the upper thread, I don't want to tackle 2 problems at the same time. 

 

[Uwe]

You are probably talking about the check spring on your thread tension assembly. If by "turned the controller back and forth" you mean turning the little thumb screw nut on the check spring split post, that unfortunately is NOT where you adjust the tension for that spring. That thumb screw nut is more of a lock nut that holds the check spring discs in place.

Your check spring should be able to move freely.

Sometimes the spring gets caught under the thumb nut as you tighten it - that prevents the check spring from moving freely and operating properly.

Make sure your check spring moves freely and then see if your problem persists.

The tension of the check spring can be adjusted, it's just not obvious how it works.

I was motivated and made a video that hopefully explains how the check spring adjustment works:

 

[tmitch]

Thank you for the reply, but unfortunately or fortunately, I was doing it correctly.  So my original problems still stand.  I have moved the lower stop as far down as it will go, and turned the tension back and forth and as I said, too much tension and it won't reach high enough and too little and it won't return to the lower stop.  I have felt the spring movement and it seems to move freely.  I was unsure if the outer part of the spring belonged on the outside of the "disc" since I had taken all apart, but your excellent video clearly shows that I had reassembled it correctly.  In trying to get this machine working correctly I had to readjust the stitch length to match the numbers, which somehow, screwed my original timing, so I had to re time it again and now I think I have it just a little early but again, I want to solve this loose thread controller problem.  In all the videos I have watched of similar machine running, none of them seem to exhibit as much loose thread as I have.  Maybe that is not my problem.

I don't have enough strength to lift the machine straight up out of the hole in the table, as I don't yet have the female parts of the hinges so I have to keep calling my son every time I need to work on the underside of the machine.  I can't believe this thing is so heavy.  No wonder Singer called my old 306K a "featherweight".  

[Uwe]

Post a few close-up pictures or, better yet, a brief video of your threading path and what's wrong with your machine (ask your son to be cameraman for a moment.) There may be something else going on but it's hard to figure it out without seeing it.

[tmitch]

I'll try to do that (but I don't know how to attach a picture or video to a post), but something even more weird just happened.  When double checking my timing, I found the right hand hook assembly was almost 180 degrees off.  Thinking I had made a mistake, I corrected it and made sure the two hooks were in sync.  I then tried a couple of stitches which resulted in a rats nest under the stitch and a tangle of threads caught down in the machine.  I just got it untangled and unbelievably the right hook assembly is again 180 degrees off.  How can that happen?

[Uwe]

Each of the large hook gears has two set screws. One of those two set screws on each gear has to be sitting in the grove on the shaft. If neither of the set screws is in the groove the gear may rotate on the shaft as soon as the going gets tough and you have an instant mess on your hands. 

I recommend taking a break and a step back. Disconnect the belt until things are right again. You can do a lot of damage running a machine under motor power when things are not right.

Consider having a sewing machine mechanic put things back the way they're supposed to be. Then you have a clean starting point. It's hard enough getting a single needle machine to work right. A double needle machine is even more complex and not really an ideal candidate to learn the finer points of sewing machine maintenance on.

Also, have your son help you figure out how to attach pictures (look for the "Drag files here to attach" in the editing window.) You may also have to learn how to resize picture files so they're not too large to attach here. Without the ability to post pictures it will be nearly impossible to do proper remote tech support. We're all sitting in front of computers, not crystal balls.

 

Edited January 8, 2017 by Uwe

[tmitch]

First of all there are no sewing machine mechanics in the area (I wish there were).  I also realized that the hook gear set screws were not in the groove on the shaft, and have corrected that.

Here are a couple  pictures of the timing control:

As I turn over the hand wheel to make a couple of stitches, I get about 2 turns and the machine locks up with a tangled mess.  Here is a shot of the mess.

[Uwe]

With these style hooks (both single or double needle) you have to hold the threads taught for the first few stitches, otherwise you have good chance of things getting tangled up underneath, even on a perfectly adjusted machine. Here how I do it on a similar single needle machine:

 

[Uwe]

Also, on your threading path, it looks like you don't have the check spring threaded quite right. The thread needs to go up inside the channel past a little hook and then come back down towards the check spring. 

 

[brmax]

Its understandable that not many Sew machine mechanics, we just don't do the fabricating or manufacturing now days as our parents age group did many years ago.

I can say this site has been a great find for myself, both the group of people and their knowledge, but more important the ability many feel they are welcomed to share it.

On the machine I would take one of either side needle out with its specific thread top, bottom. Then move on in a complete setup as each saddle is separate, this seems to work on the non walker I have. What does come to mind and some can correct me to help out, some of these are timed at a certain stitch setting. Just something I recall

good day

Floyd