Loosening my bobbin tension has no effect. Where am I going wrong?

January 14, 2015 1:37 AM

Novice sewer here and I've got a tension headache. I'm working on piping for some cushions I'm sewing, and just finished ~16 ft worth of it without changing my thread. All my stitches were just fine. When I switched to a different color, I had to increase the needle thread tension to the point of puckering the fabric just to pull up the bobbin thread enough to balance my stitches. Please help.

My stitches look great on top, but they're now a disaster underneath. Every loosening of the bobbin's tension screw still results in a flat line of bobbin thread and top thread loops on the underside of my fabric. I've rethreaded the machine over and over...I'm at a complete loss.

I own an all-metal vintage 50s Singer machine (model 404) which lacks the removable bobbin case of newer models, so I can't pop it out. The thread I'm using for everything is organic Scanfil cotton, in three different colors, and I'm sewing on dupioni silk, if any of this helps. The bobbin itself may be causing the issue, as it's lighter than the one my machine came with, even though it's the same shape and size. I'm also not sure if it's wound properly. So many variables.

I can't really afford to take this machine in and have it serviced at the moment (especially since I'd had that done before I even started sewing on this project many moons ago) and I can't really access my more modern machine, which is in storage about 200 mi away. I don't want to give up on this project or the machine itself. Thanks for any suggestions.

posted by oogenesis to Home & Garden (18 answers total)

if the loose loops are on the underside of the fabric, it sounds like the tension on your top thread is too loose - have you adjusted that?
posted by 5_13_23_42_69_666 at 1:54 AM on January 14, 2015 [1 favorite]

Is there any dust or yarn in the mechanism, especially near the bobbin? Can the bobbin be installed incorrectly?
posted by Too-Ticky at 3:48 AM on January 14, 2015

My first thought was to rethread the machine but sounds like you tried that...hmm if your bobbin is lighter than the one your machine came with, that might be causing the issue - if it's not sitting correctly (because it's too light) I think that could cause those loops.

Also:
-Have you replaced the needle recently? Apparently they are supposed to be changed in between each project, and 16ft of sewing sounds like a lot.
- I would also try re-loading the thread on the bobbin.
posted by Shadow Boxer at 4:26 AM on January 14, 2015 [1 favorite]

Sounds like a threading problem. Put the tension back where it was. Then take all the thread out and slowly rethread both the top and the bobbin. Make sure the bobbin isn't backwards and that the top thread is going over that thing that goes up and down at the top.
posted by dawkins_7 at 4:27 AM on January 14, 2015 [1 favorite]

Adjusting bobbin tension falls under "almost never". Top tension, all the time. Also are you using the same thread on top and bottom? Trying to use 2 different threads can make it f up.
posted by sexyrobot at 4:38 AM on January 14, 2015 [3 favorites]

Sounds like an issue with your top tension rather than your bobbin, TBH, esp. given that it cropped up when you replaced your thread. When you pull each thread from the machine, is the bobbin thread super-hard to pull and the top thread normal, or is the bobbin thread normal and the top thread super-loose? I am guessing the second.

I would replace the needle and return the bobbin tension setting to where it was before. Re-thread everything, slowly, with the needle in the all-the-way-up position and with your presser foot up. Try again.

If that doesn't work, try (carefully!) dis-assembling what you can and removing any lint from the bobbin area. And then re-thread, again, with the needle all the way up and with your presser foot up.

And if that doesn't work, rewind the bobbin or look for the right bobbin(s) for the machine.
posted by pie ninja at 5:22 AM on January 14, 2015 [1 favorite]

Best answer: I have a Singer 7184. I had similar issues and learned an easy solution. When I thread the top needle, I need to give a surprisingly firm pull on the thread to seat it into the slot between the disks behind the tension knob. I had been just letting it rest in there.
From images I found online it looks likes the 404 has a very similar tension knob. Try putting the tension back where it was, and when you thread the top needle give the thread a really good pull to seat it well down into that slot.
Please let us know if you get it resolved!
posted by evilmomlady at 6:06 AM on January 14, 2015 [1 favorite]

This happens with my Singer when:
* As everyone has said, the machine is not threaded properly
* The top tension is set wrong
* The top thread is not properly pulled through any 1 of the 3 thread guides it goes through before the eye of the needle
* The bobbin thread is not properly pulled through the bobbin thread guide hooks
* I had inadvertently disengaged the feed dogs

If your machine has not been cleaned or oiled in a while, that could be the culprit (again, as suggested above). Try de-linting the bobbin case with a soft bristle CLEAN paint/make-up brush (and some tweezers) as well.
posted by crush-onastick at 6:49 AM on January 14, 2015

It sounds like you may have the bobbin threaded incorrectly. I've done it many times, with results as you describe. That's the thing you changed, so the most likely culprit.
posted by ssg at 7:15 AM on January 14, 2015

I've had similar problems due to using wrong thread, or yes, having the feed dogs disengaged without realizing it (without thinking, I was trying to compensate by just pulling the fabric along - are you pulling? You shouldn't need to.).
posted by LobsterMitten at 8:26 AM on January 14, 2015

So, I had a problem similar to this recently. The answer was that it needed a lititle help starting.

You may want to try what I did (can't hurt):

Reset the tension back to average.
Make sure the bobbin is threaded and set correctly according to the manual (find online if you don't have it).
Rethread the machine. Give an extra few inches of length at the needle.
Very, very slowly, move the needle down and up so that it pulls out the bobbin thread.
Grasp and pull the bobbin thread out a little more, and hold on to it and the needle thread.
Place your cloth, bring down the presser foot, and start. Don't let go of the threads until you have a few stitches.
posted by zennie at 10:04 AM on January 14, 2015

Best answer: I am a beginner vintage machine hobbyist, and while I don't have any first hand advice because while I have a 403, I haven't done anything but lightly clean it. I've been sewing on vertical bobbin machines partly because the cleaning and tension adjustments on the bottom are much easier. But here are a couple of sources of information: TNT Repair's page on the Slant needle machines and a good general guide to tension. If you don't mind digging through blog posts, Tammi at Archaic Arcane has lots of good stuff with good photos.

If you need more personal help troubleshooting this from people who are nice and do a lot of this for fun, come and ask at the Vintage Machine subforum at Quilting Board.
posted by monopas at 10:11 AM on January 14, 2015

Also a bit of sewing equipment they don't tell you about: a piece of scrap fabric folded in half hanging out around the sewing machine. Set it all up and do some test stitching so you're not making a bunch of tiny little holes in your actual project.
Oh and 16 feet is not anywhere near as much as 'needle changing time'...more like a mile or two. You do want to check that your needle is nice and straight though. Turn the hand crank a few times and look from the side (it will usually get bent towards or away from you from pushing or pulling the fabric through the machine. Remember, you just want to guide the fabric with your hands, not force it)
posted by sexyrobot at 10:50 AM on January 14, 2015

Response by poster: @5_13_23_42_69_666, I've adjusted the needle tension looser and tighter...it was the first thing I thought to try. Above, I mentioned that the only way I could get the top thread to pull up the bobbin thread after changing the thread color was to turn up the needle tension to the point where the fabric puckers...7 or 8 on this machine. For fairly fine thread and medium weight silk, this seems extreme.

@ssg, bobbin isn't backwards...learned that one the hard way, LOL.

@pie_ninja: The bobbin thread is now super-loose and the top thread is normal, but I still get the loops on the underside of the fabric.

@sexyrobot: There is no way in hell I'd test this on the good fabric. I'm almost out of scraps :} Thank you for the suggestions regarding the straightness of the needle, though. I will check.

I'm using the same thread in the needle and the bobbin. I'll try rethreading the machine again, with the pull on the top thread @evilmomlady suggested to seat it more firmly in the tension disks. *whoo* Thanks, all, for your help! I'll try everything I haven't tried, then I'll get back to you!
posted by oogenesis at 11:06 AM on January 14, 2015

Best answer: Having looked at some information about your thread, Scanfil is heavier than what I expected you might be using on silk, even for cushions. A 30 weight thread needs a 14/90 size needle (big holes!) and would be difficult to run on the bobbin of a horizontal bobbin machine, because the tension of the bobbin case would be set for finer (usually 50 wt or all-purpose) thread. Usually a 30 wt would be used for decorative or topstitching, with a finer thread in the bottom.

Anyway, you might want to switch to scraps of something else in order to get the tensions balanced if you want to continue with this thread, because it might take awhile. And check the upper tension disks, maybe run some dental floss through them with your hands to make sure that a bit of stray thread isn't stuck there. It is quite possible that your bottom tension loosened itself after a short time with the unusually heavy thread, which made the top tension "wrong" in response.

The weight of thread is surprisingly important here, I think. Going through 4 to 6 layers of tricky fabric with that heavy of a thread, I'm surprised you got 16 feet done! Maybe consider changing to a different thread.
posted by monopas at 12:00 PM on January 14, 2015 [2 favorites]

Response by poster: Thanks, @monopas! I'm just doing two layers of silk. I didn't know Scanfil was considered 'heavy' thread, or that I might need to readjust tension more often because of it. Good to know.

Peeps. Peeps. I just learned how to remove the bobbin case entirely on this machine (YAY!!), and cleaned under it with a paintbrush, removed as much lint and gook as I could find. I readjusted the bobbin tension to that point at which there is the slightest resistance if the thread is tugged. I cleaned the top tension discs. I went back to the manual and oiled ALL THE THINGS, then carefully rethreaded top and bottom, with @evilmomlady's tug on the top thread to seat it properly. Results?

Like, OMG. NO resistance now anywhere. This thing sews like a hot knife through butter. I still need to adjust the tension on bottom a teeny bit, but my adjustments on top actually affect the bottom thread again in a way that makes logical sense. THANK YOU ALL SO MUCH *gives you all medals and resumes sewing with a giddy grin*
posted by oogenesis at 12:36 PM on January 14, 2015 [4 favorites]

You might also want to find your owners manual and use sewing machine oil where it suggests. Cant hurt!
posted by oceanjesse at 12:51 PM on January 14, 2015

(Usually it's like 1 drop of oil in the little hole under the center of the bobbin case)
posted by sexyrobot at 1:24 PM on January 14, 2015