• To determine experimentally the variation of tangential force with braking load.
  • To obtain the coefficient of friction between the aluminium drum and the brake shoe.
  • To compare leading and trailing shoes.


  • Brake drum apparatus with single shoe.
  • To have drum torque and braking load applied
    by weight hangers and cords.
  • To be a simulation of a real brake system.
  • To have simple transition from leading to
    trailing brake shoes.
  • Used in the determination of coefficient of friction.

In this apparatus s drum is attached (machined) to a plain aluminium. A cord is wounded around the perimeter of the brake drum and the free end of the cord is attached with a load hangar. Some
calibrated weights will be provided to the students which they can load on to the load hangar and apply torque onto the brake drum. Inside the brake drum, there is a single mounted brake shoe. The brake shoe has its own pivot. The brake shoe is also connected with a cord and this cord terminates at the load hangar. A load is applied to the brake shoe friction force increases. The student must then add load to the torque hanger to try and rotate the brake drum at near constant speed. The sense of rotation of the torque determines whether the single brake shoe acts as a leading or trailing shoe. Direct comparison of tangential force and braking load is obtained and the coefficient of friction determined.