it is the foot designed for zigzag and other pretty stitches. I think I cut something out in the middle for better visibility.
Over the years I've made about 50 or more 9 patch blocks testing my 1/4" ability
If they are cut 1.5" with precision, then if the block doesn't measure 3.5" when finished the problem is between me and whatever foot I'm using at the time.
Good luck. If it were easy everyone would do it, right?
ah, re: feeddogs. I don't think so on the machine I'm using for the current project, it does 9.0 wide fancy stitches. When I use my vintage machine, straight stitch, then the feed dogs are covered.
Do you ask because your patch gets pulled into the feeddogs? The quickest fix for that is pull out a little thread from the bobbin and top and hold it when you start to stitch. The more fun way is cut your self a bunch of squares in your favorite size (I'm currently using 1.5" squares) and make twosies every time you take your project fabric out of the machine, before you do run 2 blocks in and leave them until your project is going back under the needle. I could show you in about 30 seconds what I mean (leaders and enders)
bonnie explains it more clearly here
http://quiltville.blogspot.com/2005/...-and-hows.html
My friend Joan has the Jem for classes and loves it.