 high duty cycle or vibration. A potentiometer is a variable resistive device using a delicate wiper contacting a resistive element. Although the joystick may be in neutral (center) position for much of the time a machine is active, vibration from the machine can continuously dither the pot wiper on the element and produce heavy wear in the center region. Devices using contacts are always subject to wear and potential failure, but the use of non-contacting technology is a way to avoid this.