I’d always been told to just leave the bobbin case tension alone — which seemed odd … why would they have a user-adjustable screw on something you should leave alone? If it is something that needs to be set by a professional … hide it, require an odd tool, whatever. A little flat-head screw right there … but, yeah, randomly turning it certainly didn’t help my stitches.

My husband’s mother used a Kenmore 158.17520 in the 70’s and 80’s, and it was sitting around the house when we needed a sewing machine. His dad let us have it – now I didn’t really know much about sewing machines. I had a compulsory course in practical making-it-in-real-life skills in primary school, and I remember using a sewing machine. But it was all set up and ready to go (maybe we had to thread it … but there were no settings being adjusted). Hadn’t used a sewing machine since. I wasn’t sure how much of my thread snarl was the machine and how much was my ineptitude.

Replacing the bobbin case improved things greatly, but I continued to get inconsistent results from this machine for years. The bobbin thread would be loose, and often snarled. Then I took a class in operating a long-arm quilting machine. There are some quilt projects I can do on the Kenmore (although with the loose bobbin thread & having to rip and re-sew … even that was iffy), but I have designed a computer controlled quilt motif for Anya’s butterfly quilt that creates a sun and rays in the upper right-hand corner of the quilt. And when she’s older, the star quilt is going to have a sunburst that would probably be easily done free-hand, but I know the lines would be straight and spaced properly if I build the design with an algorithm. To use the computer control, I had to know how to use the long-arm. I think I’m going to have an audience when I use my quilting design on their software … seems that there aren’t a lot of computer techies loading up complicated custom designs. But I need to make the quilt first!

Some of the early lessons on the long-arm were basic set-up. How to mount the quilt, how to thread the machine (which, I realized, was a pretty standard sewing machine from a different perspective and attached to a giant computer controlled rail system), and how to set up the bobbin. And the instructor said don’t mess with the bobbin tension. I asked her why — I’d read it online but never heard it from someone I could ask “why?”. We did it already, she said. I know this case is set up for the thread I’m using on this machine. They even drop some nail polish over some of the adjustments to avoid people screwing with the settings. Which begged the question … how did you set the tension?

She showed me that she could hold the bobbin in one hand with the thread between her thumb and index finger, put her other hand 4-5″ under the hand holding the bobbin, and drop the bobbin. It stopped itself just short of her hand. If it plummets and would continue dropping (especially if it will drop all the way to the floor), then your tension is too loose and you need to adjust the screw clock-wise. If it doesn’t budge, your tension is too tight and you need to adjust the screw anti-clockwise.

Now there’s a middle-ground. Generally 4-5″ of drop is good. It could drop 3″ or 8″ and maybe be OK. Depends on the thread being used & the upper tension setting. That’s where you get into trial and error. Sew something — if the bobbin thread is loose, then the tension needs to be tightened. If the bobbin thread pulls up to the other side of the fabric, the tension is too tight. Once you know the right amount of drop for a specific thread, then you have a setting for that thread going forward.

Then she mentioned that this machine needed the bobbin put into the case so the bobbin would spin clockwise as you pull. Wait, the bobbin insertion is directional?? Problem is that I cannot figure out if that’s clockwise as you look at it while it is in the machine or as you look at it out of the machine and are putting in the bobbin. Hopefully the manual indicates which is proper … but I think trial and error will figure it out too. I’ve noticed snarls, taken out the bobbin case to look at it, put it back together a random clockwise/anti-clockwise direction, and had the problem sort itself. Maybe I’m flipping the bobbin in its case?

But even without sorting the spin direction, I am getting consistent stitches with the bobbin tension sorted. WooHoo!!