Inconsistent tension issues on my Singer 111w155

[Brynn]

I recently bought my first "leather sewing machine" a Singer 111w155 and have been tryin to get it to sew properly. I bought it as "working", it looked decently oiled and taken care of but hadn't been used in awhile. I was having some issues with tension... and maybe abit of jamming also. (I mostly sew 3-6 oz chrome leather, sometimes multiple layers.)

So i cleaned it all out well with varsol and re-oiled it up. Got rid of some troublesome fuzz in the process. It still wasnt sewing great so I went through all the timing stuff. Watched the UWE video on consew 225 timing like a hundred times and made the nessessary adjustments. It has a brand new needle, I've rethreaded it many times. Taken apart the tension discs to make sure nothing was stuck in them. Experimented with foot pressure.

Problem: It seems like the tension is inconsistant. It'll be fine for afew stitches, and then all sudden not for a stitch. (with maybe a knot of thread on the underside in one stitch as if the top tension is too loose. Or for a few stitches all sudden ill see the bottom thread pulled up to top as if the top tension is too tight. Kind of random. Ive adjusted it many dif ways, top and bottom. Something I noticed right away is that it seems like the top thread is not always consistently tight. It's super hard to pull through by hand unless the tension is loosened so much that it makes a really messy seem. And it seems kind of "catchy", sticky, like not smooth to pull through. Maybe this is all normal. Its my first industrial machine. 

So I dont know if this all makes sense but it seems like something is funny and im not sure where to go from here after cleaning and timing. What other things can affect tension? Any help would be muchly appreciated 😀 

Edited August 25 by Brynn

[nejcek74]

My first thought is to check whether the tension release pin is working properly. The thread is released when the foot is lifted and the tensioner works when the foot is pressed down. Material that is too thick or a foot bar that is set incorrectly can press the release pin enough while sewing to release the tension.

[friquant]

35 minutes ago, nejcek74 said:

My first thought is to check whether the tension release pin is working properly. The thread is released when the foot is lifted and the tensioner works when the foot is pressed down. Material that is too thick or a foot bar that is set incorrectly can press the release pin enough while sewing to release the tension.

Yes @TaperPin made a solid post about this last week here: 

https://leatherworker.net/forum/topic/133425-pfaff-145-bunching/page/5/#findComment-796943

I would add that in order to quickly rule out whether the tension release mechanism is part of the problem, you can temporarily remove the tension release pin from your machine and run some test seams. If that solves the problem, put the tension release pin back in and get it adjusted properly. If it doesn't solve the problem, then you can start looking elsewhere.

A couple more posts about tension release pins:

https://leatherworker.net/forum/topic/95096-pulling-my-hair-out-over-tension-issues-with-consew-206rb/#findComment-647261

https://leatherworker.net/forum/topic/133425-pfaff-145-bunching/page/4/#findComment-796922
 

 

[Brynn]

Thanks for your responses. I did not know about the tension release pin. I took it out. I dont think it helped. Ill attach pics of some seams I sewed with it out. I should maybe sew some more like that yet and experiment with the tension. 

A question: the issue you're thinking about would be that the tension would randomly release when it shouldn't? I dont think that pin is working like it should but id sooner say it isn't releasing when it should. It should release when the foot is lifted? It doesnt nessessarily. And the upper thread is so "catchy" when I pull it by hand through the upper tension disc. It seems to get stressed ill attach a pic of the thread. Its not usually that bad tho. 

[friquant]

30 minutes ago, Brynn said:

It should release when the foot is lifted? It doesnt nessessarily.

Yes it should release when the foot is lifted, but only right at the top of the foot's travel. Good idea keeping the release pin out of the picture until this issue is sorted.

 

You mention the thread looking stressed. This photo shows your thread is coming unwound 

When thread is unwound like that, sometimes it means one strand (out of two or three total) has been severed. Other times it means your hook has grabbed one or two strands instead of all threee, spread them apart, and then they went back together unsevered but sloppy looking. You will want to get that figured out one way or another.

 

30 minutes ago, Brynn said:

And the upper thread is so "catchy" when I pull it by hand through the upper tension disc.

I would definitely inspect your entire thread path for burrs. Burrs are usually detected by thread fraying or breaking when you floss thread over the area. I would start with the tension unit. Thread just the tensioner, unscrew the tension knob until the spring starts to flop around (is applying no tension), and "floss" the tensioner back and forth several times. Ideally the thread flows smoothly in both directions. If it feels scratchy when dragging the thread in one or both directions, figure out which part it feels scratchy on. If there is a burr, the thread will at least get fuzzy looking and at most will break after several passes.

I would also inspect the inside faces of your tension discs for grooves. 

[TaperPin]

Congrats on your first industrial!  The 111w155 is a great machine and will be trouble free for a long time once the kinks are worked out, kind of like a Toyota Corolla in the reliability department.  It’s good to start with the easy stuff, but you’re on a steep learning curve and it’s a lot to take in, let alone make sense out of.  Keep in mind every part of these old machines have been molested for many decades by techs and operators that know something between a lot and very little.

Double check the thread path to make sure it’s correct.   Read up on setting bobbin tension first, and then upper tension.  Too much bobbin tension requires too much upper tension.   Then, it’s good to look for deep grooves anywhere the thread passes through.  If the previous owner sewed with thinner thread than what you’re using, the small groove can catch and bind thicker thread.

Unlike residential thread, industrial spools are wound so the thread should pull off the top with the spool sitting motionless.

It’s always good to try some different thread, the same thickness and/or thinner, to see if the problems go away.  With age, the stuff that makes bonded thread stay together dries out and thread is more likely to be finicky compared to a good quality new spool.  If thinner thread sews just fine, I’d focus on those small grooves in the thread path and sand any grooves so thicker thread passes easily, and make sure the bobbin is compatible with thick thread.

 

 

[nejcek74]

5 hours ago, Brynn said:

I did not know about the tension release pin. I took it out.

Pin should be inside the machine, but it needs to work. If it is not, you need to check what's wrong and solve the problem.

Beside everything written above by others, are you basics fine:

is the needle size chosen right according to the thread thickness and according to the machine characteristics? There are pinned threads at the begging of the "Home>Fabrication>Leather Sewing Machines" sections, one is speaking about choosing the thread size.

[Brynn]

Ok ive been going over my thread path. That pin with 3 holes (right before the tension discs) has a worn path but I wudnt say burrs. I took apart my tension discs again and scrutinized them closely. (Earlier I had run them over fine sandpaper just in case that was the issue.) Ill attach pics of them. I cant feel anything with my finger but there is the tiniest trace that I can see, where the thread path goes. I have no idea of that cud be enough to cause issue cuz its pretty smooth. What's that thing called thats next to the first tension discs? Anyway I cant see too well into that but I did run the thread back and forth in there to see if anything caught. Next I did an experiment. I'll attach a video. There's obviously an issue in the tension discs area. I show myself pulling it through by hand and all sudden it goes real hard for abit and then its easier again. That wud explain the inconsistent tension problems I seem to be having maybe. Seems like the problem must be in that area? Unless its the thread - Im using the thread that came with this machine. Possible quite old? I should buy some new stuff since one of you mentioned that it deteriorates... I dont know for sure but is probably Tex138. I'm using needle size 23. Ive tried both 24 and 22.

 

 

 

[Brynn]

O and I forgot I was going to attach this pic. Thats where the tension discs sit. There's some damage. Wud that affect anything?

[friquant]

Your video is illustrative. What happens if you repeat that but with the tension much reduced (or no tension at all)? I'm trying to see if the intermittent additional tension is coming from the tension discs or from the thread controller. You could also floss just the tension discs, or just the thread controller.

What about the inside of the thread controller? Anything grabbing on that? You can remove the thread controller and visually look down in between its two plates.

What about the little tang on the thread controller (right before the thread reaches the check spring)? Is it smooth? Any thread abrasion happening in your tests?

 

As a nice to have, I would sand the faces of the tension discs again. Place your sandpaper on a flat surface like a piece of glass or a flat looking countertop. Sand until you can no longer see the original grooves. No need to sand anything but the faces.  

By the way, you can buy replacement tension assemblies. It would be satisfying to understand what's going on with this one through.