Yesterday I was sewing up a few projects, and for some reason I can't fix the lower tension on my machine. Its all LOOPY and loose and just a mess! I've tried different thread, changed needles, took the machine apart and cleaned it all out, but still major lower tension problems. What is the cause of this? And it will even do this on just cotton fabric..I'm not even talking the heavier stuff.
Also, I did drop the bobbin casing on the floor (wooden floor, and dropped it yestedday) and ever since then, it doesn't work properly. This is a metal casing and it doesn't look damaged to me at all.
Thoughts and help??!!