Introduction - If you have any usage issues, please Google them yourself
Elevator control. Elevator shaft can be plexiglass model of some visco supreme cover into the hexahedron ABCDEFGH, high AE for 1.2m elevator car model bridge J by flying through the pulley traction motor M, can model elevator shaft up and down movement of the space. Model of the elevator shaft at intervals of 20cm from the bottom layer is divided into 5