katierose

So I have a pretty strange tension issue and I'm hoping someone out there can help me! Recently I was hemming a t shirt using a twin needle. I had to loosen the bobbin tension quite a bit to get a good stitch. Ever since then I haven't been able to get the bobbin tension back to normal. The first few stitches will be nice and balanced but then the next few stitches the bobbin thread is too tight, then back to balanced for a few stitches, then out of whack again, and so on. There's also a clicky chattery sound coming from the bobbin area. It gets louder when the stitches are unbalanced. I've already cleaned and oiled everything and checked the timing, but other than that I have no clue what to do!!

Mickey2

I would go through the basic points, check thread route, take out the bobbin case, double check for correct postion and it clicks correctly in place. You could always oil the edge the bobbin case rests on. Check if the needle goes all the way in, sometimes dirt and grime has accumulated behind the clamp. Make sure the needle tip is sharp and fine. I usually only adjust upper tension for double needle, but I often adjust bobbin tension for thicker thread, like going from sew-all weight to top stitch. Bobbin in the correct way! Check for lint or piece of thread in the top tensioner.

If the stitching is fine on two layers of quilting cotton the trouble might be else where. Fine slippery jersey with viscose and lycra can act up, personally I have found lessening presserfoot tension has helped a lot. Sometimes a microtex neelde or ball point needle turn out to be a must. If it's a firmer all cotton knit it tends to be less fuzzy. Matching needle and thread tickness is important too, it needs to be within reason. Sew all Güterman polyester is very easy to get a nice stitch with, and much the same for good quality mercerized cotton. I use all kinds of thread, but when I am trouble shooting I aim for the most dependable thread I have.

quiltedsunshine

Are you using the right bobbin? It needs to be a metal 66 class bobbin. If it's a plastic bobbin, is it damaged around the edge? Are you using good thread? You never want to sew with "hand quilting" thread in your machine. Is the spool of thread moving freely? If not, put an empty bobbin underneath it. Is your tension release working? When you lift the presser foot, does the upper tension release?

OurWorkbench

Welcome, katierose.
Did it work as expected before you adjusted the tension?
Did you mark where it was before changing it?
Do you have a manual for your machine? If you don't you can download one from http://www.singerco.com/support/instruction-manuals
Near the end of the manual there should be instructions on "Remove And Replace Bobbin Case" before instructions on lubricating the machine. I would suggest making sure that area is clean and replaced correctly. Perhaps the bobbin case holder is not seated correctly. Maybe it got bumped when you were trying to adjust the tension.

Janey - Neat people never make the exciting discoveries I do.

ETA - I'm sure it probably won't help this particular problem, but there is a thread here -- She's real fun, my 401... about using 30W oil to help this series of machines (only where the green arrow is). See posts #9 & # 15. It also has regular oiling places with regular sewing machine oil.

bkay

My 503 was acting up. It was skipping stitches and clattering. So, the first thing I did was oil the edge of the bobbin case. It stopped skipping stitches and sounded quiet again. It has some problems with the feed dogs that need attention, so this might not be applicable to your problem, but I thought I would mention it.

bkay

cashs_mom

This won't help you much at this point, but I was told to always have 2 bobbin cases. One to leave alone and one to adjust. I've done that with my Bernina.

Edit: I've never had to adjust by bobbin tension for using a twin needle. Why were you adjusting bobbin tension for that?

bkay

Patrice, the 401 (403, 501 and 503) have drop in bobbins, so the bobbin case is seldom removed or adjusted.

bkay

katierose

Thanks everyone for your responses. This was driving me crazy all day at work! It turns out the problem was the bobbin. I've been using metal class 66 bobbins from sew classic. I've been using them for at least a year with no issues. But I found a document on tandtrepair.com that says that as the bobbin case gets worn, the metal bobbins will ride too low and cause the upper thread to catch. The solution is to use plastic bobbins. So I tried one, and it worked! I'm getting perfect balanced stitches now. Still getting noise from the bobbin case rattling around so I'm going to check the hook for burrs when I have more time. But if the hook is ok then I guess I can live with it.

OurWorkbench

Glad you let us know what helped.

Janey - Neat people never make the exciting discoveries I do.

Mickey2

Haven't heard of this before, but there's probably something to it. I would inspect the bobbin case for wear marks, hook and race too. Parts can luckily be replaced. These parts are usually fine on machines that's seen quite a bit of use for decades on end, so it's worth further inspection.