• To investigate the ratio of belt tensions when a rope passes over pulleys of different Vee angle.
  • To determine the coefficient of friction between the steel pulley and cotton rope.
  • To assess the variation of belt tension ratio with lap angle.


  • Determination of the coefficient of friction between a steel pulley and cotton rope; investigate belt tensions; evaluate effects of different `V` angles in the pulley, and of different lap angles.
  • The wall mounted apparatus consists of a fixed pulley, a second interchangeable pulley and a loaded rope belt with 2 load hangers in a complete loop.
  • Four pulleys with Vee grooves typically of 60o, 90o, 120o degrees and flat rim supplied.
  • Alternative mounting positions provided to vary the lap angle.
  • An Instruction manual for student and lecturer provided.
  • Set of weights.

The apparatus consists of a wall mounted fixed pulley with a loaded belt. Four different pulleys are supplied with different vee groove angles; flat rim, 120°, 90°, and 60°.

A load is added to one of two hangers until the rope just begins to slide. This is the datum condition. Loads are now added to both sides of the rope to cause very slow sliding of the rope. This enables the coefficient of friction to be obtained.

The angle of lap can be easily varied.

A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.