A lot of people that use the Bobbin Genies use them wrong. The bobbin case spring (usually flat metal) has to come out of the bobbin case. It's easy to take out and put back in. I took a class not from a machine quilter ( Machine quilters show you how to machine quilt and what works for them) but from several thread, needle and machine experts. Always start with the tension at 0 and move up 1/2 until the stitch is perfect. Always use a topstitch needle and match to the thread wt and ply. Always keep a journal of what needle size/brand you use with size thread/brand, and what type of batting and what tension settings you use. The journal has saved me many hours of frustration. It takes a lot of trying out needles and thread to get a perfect match, don't waste that perfect combo, write it down.