I'm making some tree straps out of nylon webbing. I keep running into this big mess under the strap when I pull it off of the machine.

The top side looks perfect, but again when I pull off the strap and flip it over I have a huge mess of thread under the strap (bobbin side), with about 10 different threads going from the different points on my stitch down into the bobbin hole.

Has anyone seen this happen?

I sewed some jeans last night with no problems at all.