I have been doing some load tests of servos. I am using a Vexa ServoXciter to generate the pulse and a digital fish scale as the torque readout. I drive the servo thru a heavy duty y harness to the servoXciter for the pulse with the + lead disconnected. The other input to the Y harness is connected to a 1500mah ni-cd with the pulse lead disconnected. This way the servo gets the pulse from the ServoXciter and its current supply from the battery. The servo is connected to the digital scale with a kevlar string attached to a H9 servo pull-pull wheel.
I have been unable to get the rated torque from the high torque servos. For instance the 9206 is rated for 133 oz-in. The best I can get is 100 oz-in. I have two 9206's and two 9204's that show similar results. The two 9250's that I have run about 10% low. I have 9202 that is better than its spec by about 10%. The standard servos I have tested show results exactly as the specifications read.
Do you have an explaination for this?
Richard H. Kelly
[email protected]
PS I am a retired graduate electrical engineer. During my career I performed many such tests in the engineering department of the Boeing Co.