My buddy broke 3 flex plates on his BobCat a few weekends ago flying off a grass field that looked like a golf course. I took a good look at one of them. It was made from what I know as "Black Phenolic" . The landings were almost "Grease jobs" and in my estimation the plates should have held up. They broke right at the holes. What a pain.

I realize that these act like a shear pin on a snow blower but you shouldn't have to replace them after every flight. Poor quality material.