SQUISHING...When I first tried quilting this project, I rolled the right half of the quilt and slid it into the throat of my machine...with the right side of the middle block under my needle. Had I been quilting a totally straight line, I probably would have been okay. However, I was quilting tumblers. Changing the angle at every row was darn near impossible with the rolled up quilt in the throat of the machine. It was too solid, too rigid, and absolutely REFUSED to cooperate! I pulled the quilt out of the machine and reinserted its middle under my needle...while squishing all of the fabric to my right. EUREKA!
SUPPORTING...Supporting your quilt is just as important to your overall success. It is amazing how much a little "drag" contributes to the "quilt wrestle". You should not have to fight to move forward in your stitching. Ideally, your quilt should be SO supported that you are able to move the quilt sandwich under your presser foot or FMQ foot using only the pressure of your fingertips. You will learn that quilting like that is NOT possible if there is any drag on your quilt.
When I set up my new sewing room I placed two bookcases along the back of my sewing table, specifically to support my quilt sandwich. A lot of people place a table behind their machines. However, I was not willing to give up the open space in the middle of my room. So I added these bookcases. They are 12" deep and combined with the approximate 11" of room on the sewing table behind my machine, I have almost 2 feet of support.
When I have reached the right side of my sandwich, quilting from the top down, it is time to begin the left side. Rotate the quilt and quilt from the bottom to the top, beginning in the middle once again with the unquilted sandwich bunched in the throat of the machine.
While I have yet to try a king sized quilt on my domestic machine (and doubt I ever will as my arms are too weak to heft around a king sized quilt)...there are many articles and classes available on the internet to help you learn to quilt a large project on your DM (domestic machine). What I have described above is what works for me. It is NOT the end-all and be-all of quilting on a domestic machine. Each of us has a different furniture layout in our sewing rooms and different physical abilities. My goal is to offer ONE method for you to try. It may work, it may not. Part of the fun of being a quilter is "making it your own"...and that includes the quilting! Have fun!