I have quilted a king size quilt on my dinky mechanical Brother. It was a job, but very doable. It was stitch in the ditch and it took a while to keep repositioning it, but, I didn't want to send it out. I started in the middle and worked out which made it somewhat easier. I have also quilted other large quilts, nothing fancy, but manageable. You are really only quilting the small area under the needle and sometimes you do have to wrestle the fabric through the throat plate to reposition, but, if you are willing to do that, you can do it. I don't know about using a walking foot on the curves for the double ring. I'm sure one of our other board members can advise on that. Good luck!!