I have a 350E, and I haven't had this problem....yet. So, I was curious as to what would cause it. Check out this article,
http://sewing.about.com/od/mac...ing-Bobbin-Thread.htm. It says that, most of the time, the bunching up of the bobbin thread is due to issues with the needle or upper thread. Maybe some of those suggestions will help you.
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Brother Dreammaker XE, Janome 350E, Baby Lock Elizabeth, Janome 1110DX serger, MC 4000 (retired)
Edited: 06/14/2012
at 09:48 PM
by GraceB