Dear Jan,
How can I overedge and gather fabric for a ruffle in one step? -Anonymous

Dear Anonymous,
This is very easy to achieve. Select the Overlock 4, and increase the stitch length to 4.0. Lift the presser foot and dial the Differential Feed Ratio to 2.2. Increase the two needle tensions to 4.6. The seam will automatically gather and finish the edge for an easy ruffle. If more fullness is desired, increase the two needle tensions, or if less is needed, decrease the two needle tensions. This is an excellent customized stitch to memorize for future use.