I had a problem with my Brother in bobbin area. It knotted and all sorts of nifty nests. Then I pulled the bobbin and the chuttle out. The chuttle had a rough sport on it. The books said to order another one. I had only had it about a month. Instead I took an finger nail file (not the metal one the sandpaper one) and filed the rough spot off. It worked(s) beautifully. That was four years ago.
Katrina