Rich, the visual method is easiest with hi compliance (very wiggly suspensions) like vdH, but it's not impossible even with moderately low compliance carts like the Helikon. The trick is 1.) to use a strong light pointed at the front of the arm/cart, and 2.) sharpen your obsetvational skill by carefully watching what the cantilever does with no AS, and max. AS, just to get a feel for the range of movement. You will not get it "on the nose" with a Helikon because its too hard to see the tiny deflections, unlike a vdH for instance. But you can get pretty close and do the rest by ear.
The inward twisting torque (skating force) on the arm is created by the stylus' drag (friction) in the groove times the (geometric) lever arm distance created by the headshell offset angle. So using a blank record is a waste of time. (Perfectly straight arms with no headshell offset do not develop skating force, and don't need AS)
The inward twisting torque (skating force) on the arm is created by the stylus' drag (friction) in the groove times the (geometric) lever arm distance created by the headshell offset angle. So using a blank record is a waste of time. (Perfectly straight arms with no headshell offset do not develop skating force, and don't need AS)

