PCMD, LLC. Projector Ceiling Mount Compatible with NEC M420XV V302H V302W V302X V332W V332X with Lateral Shift Coupling (8-Inch Extension)

I chose the wall because this way i can position the projector centrally in front of the screen. Now it is important that the plate is placed precisely according to the screen. I measure the exact center of the screen on the opposite wall. Since the projector lens is not centered in this device I measure the distance from the center of the lens to the center of the device. It is 10 cm. So the mounting plate on the wall must be slid sideways by 10 cm, so that later the lens hangs in the middle of the screen. I measure the distances to the ceiling and walls and use a water scale to level the plate. I draw the drill holes with a pencil and use a simple impact power driver with a 6 mm stone drill to place the four holes. I also use a vacuum cleaner to suck the drilling dust up. I use 6 mm wall plugs and the provided screws to screw the bracket on. The mount, according to the manufacturer is