Lessons learned on machine tension.
 

Time and time again machine tension has been discussed on this awesome board. I've often read about using the same thread (or type of thread) on the top and in the bobbin. But did I do it?! I tend to use whatever bobbin I grab (when it blends close enough to the fabric). I've got a lot of bobbins from my garment sewing and alterations of grandkids uniforms days. The majority of these bobbins are threaded with all purpose poly/cotton thread. Well, my Janome has had a beautiful stitch but at times, the bobbin thread seems tighter than the top tension (or the top tension seems too loose). I had the machine serviced and it came back with a beautiful tension. Lately I've had the same tension problem all over again. Hate to bring it back (service "ain't" cheap!) so I began to think about what thread I was using. Today I threaded a bobbin with the same thread at the top and voila! The tension is "fixed." I know you all know this, but I was wondering if those of you who buy the prewound bobbins have any tension problems.

And the other lesson I learned is that it's not against the law to adjust the tension even though the machine has an automatic tension setting. (Someone had a link to a great video on thread and setting tension.) So don't know if it's the change to the same thread, top and bottom, or if it's the adjusting of the tension OR perhaps it's a combination of the two.

the bobbins have to be wound with the right tension especially on my long arm I usually use the same thread in the bobbin

Same here. On my domestic machine I find that it's ***much*** easier to get a balanced stitch if I use the same thread top and bobbin.

I have a Janome, too, and just recently it suddenly went out of whack, just as you described, with the top tension being...not right. Finally I realized it happened right after I had changed the top thread for just some quick stitching in color. I had used that thread before so didn't think it could be the problem, but I think somehow using that thread in conjunction with whatever was in the bobbin closed the show. Once I changed the top thread, all was well again.

We live and we learn...

Bobbin thread
 

Made by Sulky. That is what I use however, the colors are limited only white and. Black.............calla

Superior threads recently told me you can use different threads weight on the top and bottom. I was specifically asking about bottom line (60wt) in top for SID and king Tut (40wt) for backing.

I often use King Tut on the top and bottom line on the back on my longarm. I always check the tension with a scrap on the extra fabric on the side. There I can then adjust it. Superior threads has a chart which can be used to match colors for those two threads. I have not done that on my domestic machine however.