I call this my Lower East Side rig: cheap to build and quick to install, perfect for a quick load-in and load-out. The old one was getting pretty beaten up, so version 2 is made of oak and has built-in aluminum spacers on the projector side. (I was balancing washers before).
The hardware is a baby wall plate and C-stand in this picture, although I use a mafer clamp for grabbing onto beams, shelves and pipes. There’s also an eye-bolt and safety cable.