Rings for positioning or holding blades too soft. The rings were dented when shipped, I don't know if too much force was used from the factory, but this makes it difficult to set the diameter when the rings are rotated, they hang on the blades. The wooden floor of the fuselage broke in the corner. I also found, as per other reviews, the taper along the length of the blades rather than just the beginning end. I made a 22mm hole that was supposed to be 2" deep, the taper of the blades made itโฆ