The TM 121 experimental unit illustrates the laws for forming the equilibrium of moments in static systems. The relations between wheel diameter, moment and circumferential force are demonstrated.
Two pulleys with different diameters are mounted on a steel shaft, which is itself mounted on ball bearings.
Weights can be hung on the cables, making it possible to represent different load cases acting on two pulleys with different diameters. The forces can be varied using weights until equilibrium is reached.
The experimental unit is designed to be fixed to a wall. The parts of the experiment are clearly laid out and securely housed in a storage system.