I have two wooden plates with the same dimensions (5 cm thick, 50 cm long and 35 cm wide).
The distance between plates must be at least 10 cm. Plate P1 is fixed but P2 rotates about the y-axis. Angle alpha can go from 0 degrees (when the plates are parallel) to at least 90 degrees.
How can I realize this design in practice? Which mechanical elements should I use? It must be strong, there will be load of max. 30 kg hanging on plate P2. There must be some mechanism that will connect these two plates and enable P2 to rotate but when one sets a desired angle between plates, the mechanism must hold the angle constant.