"You can use any quilting foot, but just be sure to have the correct ruler foot suitable for your machine" This was copied from the link you provided. This statement seems to contradict itself. Ruler work with all these curves is basically a form of free motion quilting with your feed dogs down and yep, you would need a specific ruler foot for your machine, and specific rulers designed for your type of machine. My Bernina needs the 1/4 inch thick rulers for ruler work. These would be too thin for me to use.