I had one of the pan-head screws that hold on one of the grips fail. My local hobby shop sold me some socket head screws. Seems to be fine now, but the blades to not have clearance to fold back. They bind on the "taller" socket head screws. When I first looked at the size of the pan-head screw that holds on the grips, I nearly crapped my pants. There's no way that there is enough meat there to keep the centifugal forces from spitting a blade. I've got 20+ years fixing the real thing, and it didn't take long to figure out that there is an engineering issue here.

Avtech98