Why are "Tuning Constants" of identical Servos in identical machines different?

Hello everyone,

Thank you for the opportunity to join the forum. I have recently started to work with Servo in the realm of "Custom Machinery" and to my great amazement, I found out that machines built from the same electrical schematics and assembled from the same mechanical drawings using the same make and model servos, nearly always require different tuning constants. Sometimes, the difference can be almost as high as 25%.

Can anyone kindly explain the reason for this apparent paradox?

Thank you for your time and considerations

Cheers :thumsup: