I have a mega quilter and frame - I never did have trouble with the tension until this last quilt ... I usually use star thread but tried gutterman thread - it would sew sometimes and then other times NOT - I took the machine apart and cleaned it thoroughly - fiddled with the tension and at this point I have not tried it again... that quilt was an albatross quilt.... anyway I have practiced on a piece of other fabric but have not done anymore.... I usually use star because it is the only one without ordering from catalogs I can buy at the store here. So, I hope this helps - watch the way it is threaded also. and check bobbin for any stray threads that may be caught in bobbin... If you still have problems let me know...