Path49,
This time I wasn't piecing, but was getting the machine set up to put decorative stitches on the squares already done. I have been using some of my wife's brightly colored serger thread for this as it takes a lot to do tight patterns.
This machine just had fits with it. None of my others have had any trouble at all.
We had a 16 needle in it as my wife was sewing some heavy denim pockets on her shopping bags the last time she used it. That needle was switched for a 14, the bobbin tension lightened, and the top turned back and forth and ended up near where it was.
I went from the light weight variegated thread she had in the bobbin to a size 50 I'd guess and from the light thread I've been using for my patterns to a heavier thread intended for jeans top stitching. Now it's working.
So now that some of my squares are dry I'll be messing with this machine again.
As far as using the heavy thread for piecing, I got the White DRESSMASTER figured out. The causes were, A: Needle to small. Went from 14 to 16.
B: Bobbin tension too tight. (I had not adjusted it previously. It was as it came to me.)
C: Had the machine threaded partially wrong.
Now it sews with the heavy stuff just fine. I'm gonna use it till it's gone. Too expensive to waste.
Joe