I was quite amazed by this. I had never seen or even heard of a Magnus Effect plane until Finley showed up with what looked like an upside down lawn mower. He's a very articulate kid and talked me through the physics of how this thing works. It doesn't just work...it flies really well...and he built it totally from scratch. Quite looking forward to seeing what he comes up with next.

Ingenious!

Congrats to Finley on a wonderful achievement.
Amazing to see how well it flies.
Besides researching the rotor, he must have put in a lot of thought and effort into solving other problems like CG and thrust line location...

A control line model design using rotary wing panels was published by one Mr Roland Mayer in the Flying Models magazine. In 1949!

https://outerzone.co.uk/plan_files_05/5046/Flutter_Wing-MAN-07-49_oz5046.pdf

I will ask him how much work went into it when I see him next. As you say, I suspect lots of time researching.