I know this post is old but just Incase it helps others, I just did free motion quilting on my brother 400se. I lowered my feed dog, removed the foot exposing just the needle, did straight stitch and minimized my stitch length to .2 which is as low as you can go and it worked fine. Key thing also is to use your auto sew at either medium or fast. Going slow you tend to hesitate with your motion, unable to create a flowing motion.