For motor-just applications, the slower the electric motor speed, the larger the motor needs to be. Large speed gearbox motors could be expensive and may not match within the allowable envelope space of a credit card applicatoin. Using a gearbox with a smaller sized motor enables the unit to use at lower speeds.

In order to understand the need for using a gearbox to diminish motor speed, think about this scenario. You possess a pastry conveyor that adds cherry filling as the pastries pass. Because this is a fairly light load, you would not want the conveyor working at 5000 rpm. If it was, there would be pastries and cherry filling everywhere!