So, here is the mobile we made for Finn. I contacted a lady on Etsy who custom made the disks for me. I should have ordered twice as many so they were on each side of the string, but for a first time attempt, I don't think he will mind so much.
First, Lily arranged the disks in a "pattern" (She wanted to help so bad, but I was working with hot glue so that was the only thing I could find for her to do.
The camera died after that, but I held a 2' length of fishing line in the middle of the strip and DH dotted some hot glue on the top and bottom to hold the string in place. This is where I wanted doubles, we could have just glued the disks together and no one would have seen the fishing line at all.
Oh well...
I then wrapped the inner part of a wooden embroidery hoop with ribbon, dotting it with hot glue every few wraps to keep it tight.
I finished it with a ribbon to hang it up and DH hung it from the ceiling with more fishing line (after I took this picture of course)
Overall, I was pretty happy with the way it turned out and it was the cheap modern mobile I wanted for his corner, with the gradation of color that is supposed to help them with their vison and seeing the differences in color.
BEST PART: Total Cost $ 6!