When two oscillators are vibrating assemblies are brought within close proximity of each other or are connected by a common link, they have a tendency to try to synchronize. The quicker synchronization occurs the better. This is one of the most misunderstood facts about Besser vibration.

If the speed of two vibrating shaft assemblies are not equal, the higher speed vibrator will raise the speed of the slower vibrator. The higher speed vibrator will then lag by a certain phase angle. This loads down the higher speed vibrator causing the motor current to go up while the motor current of the slower vibrator goes down. The greater the differential in vibrator speeds – the greater the lagging phase angle becomes until slipping occurs and/or production problems arise.

To properly check the vibrator speeds, disable or disconnect the right hand vibrator motor. Turn on the left hand vibrator motor and with a digital style photo tachometer, or one that can distinguish the difference of 1 or 2 rpm's, check and record the speed of the left hand vibrator sheave. Turn off and disable the left hand vibrator motor. Enable the right hand vibrator motor and do the same checks on the right hand vibrator sheave and record the information.

Compare the two readings to determine the differential. In today’s high production plants, where every fraction of a second counts the optimum rpm differential is 5 or less. A higher differential may result in premature mold wear and lower production rate cycles.