Extremely poor quality of the case!
I got the planck from the March Massdrop batch, received about 7 months later, and just managed to build it last week. The top plate become wobbly after few days of use, so I tried to screw it tighter, only used a little bit of pressure and the female screw thread of the case is ruined, now I can screw forever on three of the five screw holes. The aluminium case is literally as soft as butter.
