Not sure how old your machine is but mine came with a darning plate that you just put on top of the other plate. I was having many issues with breaking thread and eventually just took the machine off the frame. But I did get a new free motion quilting foot along with a new darning plate.
This is what it looks like (not familiar with this particular seller, for illustration purposes only
) )
http://www.kenssewingcenter.com/jano...t-p-29757.html
It might help some of you