Becky Andersen

Clean your upper tension discs well. When you have wonky stitching on the bottom it is usually an upper thread tension problem. Fuzz or thread can get stuck in there and cause the upper thread not to fully engage into the discs.

Stitchnripper

I don't think you can add them from the phone - at least I haven't found a way yet. I hope you figure out your tension issue!!

PaperPrincess

It sounds to me like your upper thread tension is off. To verify, sew a bit on a test piece of fabric with different color thread in the top and bobbin. I am also thinking you might have something jammed in the tension discs. with the foot up, take a piece of strong thread and 'floss'. When you rethread your machine, your presser foot needs to be UP for the threading process, until you get to the needle. Give the thread a small tug to seat it in the discs, put the presser foot down. at this point you should not be able to draw the thread thru the machine. Then thread your needle.

blzzrdqueen

I just took the machine apart, thouroughly cleaned every piece the thread touches and re-threaded the way you said to. My first ten lines of stitching came out great, then bam, all wonkey again!! I don't get it.

Tartan

Does your machine use plastic bobbins? If so, try filling a bobbin just halfway and see if that makes a difference. Plastic bobbins can distort if filled too much over time.

slbram17

This is from my experience. Check the bobbin case thoroughly, it could have the tiniest bit of thread in there. I had to use a dental pick to retrieve from my bobbin case. And it has happened to both the top and side loading machines. My tiny bit of thread was between the tension wire on the bobbin case.

Pennyhal

Have you tried resetting the bobbin tension? There is a little screw there that you turn. I put a tiny mark with a permanent marker on the side of the bobbin case to mark where the screw was originally set so I can go back to that setting. Remove the thread from the bobbin case before you set the tension.

Since the bobbin stitching was normal for just a little way and then got wonky, you may have to take it in for repair.

Jeanne S

Is there a little adjustable screw around the bobbin casing? Tightening or loosening that screw is how I adjust the bobbin tension on my Juki. If you have checked everything else, changed needle and thread, it may be the machine timing is off somehow and you will need to take it in for servicing. That can be so frustrating.

JustAbitCrazy

Since you need to increase your top tension to the max, you need to increase your bobbin tension. If there are two screws on the outside of the bobbin case, the screw you need to turn is the larger of the two, and you need to turn it slightly clockwise. (Righty tighty, lefty loosy). Only tighten it in small increments, checking the stitches it makes at each adjustment. Once you get the bobbin tension corrected, you can adjust the top thread tension to match, and it won't need to be tightened all the way. It may even need to be loosened.

PaperPrincess

So sorry you are still having problems. It always happens in crunch time.
Did you use 2 colors of thread to verify we are dealing with the top thread or bottom thread? THat will really narrow down the issue.
One other thing. If it sewed OK for a bit, then started behaving badly, were you able to see if it was still threaded correctly? Did it stay in the tension discs? Did it jump out of the takeup lever?
When it messes up, it's a good thing to look over the threading before re-threading...
One other thing, did you try a different thread? I've found that some colors from the same manufacturer won't work in my machine. Usually it's a really dark color, and I think it makes the thread stiffer and more prone to jumping out of the take up lever.
I know lots of posters are saying to look at the bobbin, but I really think it's the takeup lever or the tension disks.