Tbg...I did think of the situation where downforce is applied by a spring. My old Empire turntable worked that way, and I believe it is the best approach because the arm can be mass-balanced so that vibration effects are minimized. With a spring the VTF will be affected by arm angle, but the question is, how much. In the Empire the downforce spring was a multiturn clock spring, and I doubt that a couple of degrees would have much effect.
But I do wonder. Since you have an accurate gauge, perhaps you would favor us with some measurements.
But I do wonder. Since you have an accurate gauge, perhaps you would favor us with some measurements.