Here is a thread I started regarding issues with a rotary blade:
http://www.quiltingboard.com/main-f1...ad-t76812.html
One quilter left a link to a PDF on how to reassemble the rotary blade. Another quilt included a link to a u-tube video on how to reassemble it. It was very illuminating. LOL. I had incorrectly reassembled the rotary cutter and it worked but not well. The difference was clear once I had correctly assembled it.