A case study of the ASTM F1914 full automatic residual indentation testing machine,the drive to the specimen plate and to the castor assembly is interlocked and fitted with a reversing mechanism. The number of cycles is set by means of a pre-set counter. The rotational speed of the rotating platform shall be 19r/min and that of the castor assembly 50r/min.

After 180s of rotation,the platform shall stop and remain in the stop position for 5s, after which time the direction of rotation of the rotating platform shall reverse.

The relationship between the rotational speed of the specimen plate and that of the castor assembly causes a sharp reverse movement of the castors within the stressed area.