TUNING & SPECIFICATIONS • OEM650/OEM650X
results, the drive and motor should be on, connected to the load, and warmed up for 30 minutes prior to tuning.
Phase B Offset
Top View
Phase A Offset
Figure 3-1. Tuning Potentiometers
Gauging Motor Resonance
There are several methods that you can use to determine the level of motor resonance in your system.
Tachometer Method
Use an oscilloscope to gauge the output of a tachometer attached to the motor shaft. The tachometer will output a DC voltage, propor- tional to speed. This voltage will oscillate around an average voltage when the motor is resonating. The amplitude of this oscillation will be at its maximum when you run the motor at its resonance speed. The goal of this tuning method is to tune the motor for its lowest oscillation amplitude.
Sounding Board Method
You can practice your tuning skills with an unloaded motor placed on a sounding board or table. When you command a velocity that is near the motor’s resonance speed, the phenomenon will cause an audible vibration. The goal of this tuning method is to tune the motor for the least amount of vibration.
Stethoscope Method
When you tune your motor under loaded conditions, you can hear the audible vibration caused by the motor’s natural frequency by placing the tip of a screw driver against the motor casing and placing the handle of the screw driver close to your ear (as you would a stethoscope). You will also be able to hear the different magnitudes of vibration caused by the motor’s natural frequency. The goal of this tuning method is to tune the motor for the least amount of vibration.
34