MamaHen

If the back duel foot attachment is under your pressure foot, you need to remove it. Lift your pressure foot to the highest position, then slightly pull down, swing the attachment back & up out of your way. It won't go all the way up and you'll still see it behind your pressure foot. You only need to use that attachment when you put on the dual feed foot. I hope this helps. Did you get a manual with the machine?

In further reading of your post, maybe I misunderstood what you were describing- are your attaching the dual feed foot to your machine? That piece (if I understand you) goes UNDERNEATH the dual feed foot. By it's self it will not work, it is what makes the dual feed foot work as a even feed, or walking foot.