It took a couple of hours. Once I had all 140ft done, I wound it into a big ball.
then put the ball into a bowl under my sewing table so it wouldn't roll around the room while I was sewing the rug together.
I switched to the regular zig-zag foot as the walking foot wasn't quite wide enough for my widest zig-zag setting. I stitched the whole thing together. I did a pretty good job on the ends, easing the outer strip around the bend but eased too much on the straightaway. The result was a ripply rug which wouldn't lie flat even with a good pressing with Flatter.
So I picked out the last few rounds and re-stitched it, still easing the ends but holding the strip quite firmly on the straight parts. With a good pressing, it solved most of the rippling.
It lies pretty flat now.
It was pretty easy. I'd even consider doing another one using batting strips that I've cut myself. I think it's a bit more economical that way.
The rug is washable on delicate and can be hung to dry. It will need to be pressed flat after that.
The white thread was so neutral, it blended right in.
There were times I missed getting the zig-zagging over both strips so simply raised the needle and presser foot and re-stitched. When I was pressing it, I made note of some other gaps and just restitched them.
Before starting the project I watched several YouTube videos on the subject. I gleaned several good ideas from them. Again, the pattern had some good tips as well. One thing that helped me was a way to create a surface to the left of the machine so the rug wouldn't hang off the extender. I put the machine on a table with adjustable height and sat beside the dining room table. I lowered the adjustable table so my extender was as the same height as the table. As the rug grew to the left of the machine, it could rest on the table without drooping and hanging down, bending it out of shape. Another tip was to reserve the darkest colour for the outside. To make it all the way around the rug on the last round, you will need 4 dark strips to make it all the way around.
With that done, I have a real urge to do more sewing. On my wish list is a Bionic Gear Bag, some more project bags, a couple of zipped bags, and some placemats.