Wow, I'd say you're quite brave to start with flannel. Some people have trouble with thread breakage with it. I recently did one and had no trouble at all. I have found that I had too much trouble with breakage when I had bottom line in the top and bobbin. I then tried it just in the bottom and still had troubles. I think I'll try one of those nylon washers to see if that helps. I adjusted the tension numerous times and then gave up and used Threadart cotton on top and poly on bottom with no troubles.