I have a Singer 600 - its sitting in the garage waiting for Good Will. I just can't get it to sew more than 6-7 stitches without the bobbin popping up out of place. I've tried more than a couple times to fix it and I've just given up! I wanted it for the chain stitch ability, but I just can't get it to do a regular stitch to even be able to try out the chain stitch.