Cable telescopic frame

Turn the pink pulley to make the violet frame go up and down. Each of the red and blue cables has one end fixed to the pink pulley, the other to the violet frame. The green pulleys are identical. The weight of the moving parts ensures the cable tension. The verticality of some cable branches is not compulsory. In case of horizontal arrangement it is possible to add a second similar cable system for return motion. STEP files of this video: Inventor files of this video: