And, I believe I now know why I was having so much trouble with the bobbin. I believe the culprit was the thread seen to the right. This is some thread I bought when I first started longarming (I don't know where I got it). It is cotton and I have never seen anything as "linty" as it is.
Here you can see the lint both on the thread and attached to the bobbin itself. I was having to clean out the bobbin with each block and would come up with enough cotton lint to weave a sheet.
I even found some lint sewn into the quilting on the back of the quilt when I rolled the quilt.
I have taken some steps to make sure this doesn't happen again. Firstly I got a Bobbin Genie to put in the bobbin case. It is a DSM size but if it seems to help with tension problems, I will order the M size.
And secondly, I threw out the offending thread.
Now I just need to quilt the corner stones and the borders (with poly thread) and this quilting will be done.
When I get frustrated or tired from quilting I turn to the sewing part part of quilting. On the left you can see Block 6 of the Jelly Roll Sampler. I quite enjoyed making this block.
I also made up two more string blocks and finished appliqueing the flowers on the last border of the Eleanor Burns BOM (Egg Money Quilts).
My, my, I seem to have been busy, don't I?