A new way of adjusting anti skate!

@lewm, you are using the WRONG definition of groove velocity. It is not the linear speed of the record by the stylus. It is the actual speed of the stylus in the groove which is a direct result of the degree of modulation. The higher the modulation the faster is the groove velocity. The higher the groove velocity the stronger will be the force Friction) pulling the stylus away from the pivot. GOT IT!

No. Not to mention the fact that the skating force pulls the stylus toward the spindle. I agree that groove tortuousity does affect the skating force but not because it affects the magnitude of the friction force. Because.... for the Nth +1 time, friction is not a function of velocity. You can’t bend the rules of the basic science to explain the observation; you have to find another cause that does fit the science.

I am not at all sure I am correct, but my best explanation is that in tracing the tortuous groove, the stylus is pulled along at a "speed" dependent upon the platter speed and the distance of the styus from the spindle. The ins and outs of the groove walls however cause rapid instantaneous changes in stylus velocity, in order for it to negotiate the groove. Each instantaneous change, because it forces a change in velocity at the stylus tip, is an "acceleration". Acceleration is defined as a change in velocity, up or down. So now you have a mass (the moving mass of the cartridge) that is constantly accelerating. This would create or rather require the stylus to endure tiny forces according to Newton’s First Law of Motion (F = ma). It is those tiny Newtonian forces, which have a vector direction in the general direction of the friction force, that add to the net skating force.

I just thought of another possibility: The tortuosity of the groove causes the stylus to mistrack.  Even when we don't hear it, there is mistracking to one degree or another.  During a mistracking event, by definition the stylus loses or nearly loses contact with the vinyl, or the stylus may be driven against the vinyl.  Either type of event would have a minute and transient effect on the instantaneous VTF, the force normal to the groove.  That could indeed increase and decrease friction for fractions of a second. That could cause the ups and downs of the skating force, but not because of "velocity" or "speed" or whatever you want to name it.  Mistracking can occur in the outer grooves, where velocity or speed is maximal or during the inner grooves, where velocity or speed is minimal, and is probably worse at the inner grooves.

I am not at all sure I am correct, but my best explanation is that in tracing the tortuous groove, the stylus is pulled along at a "speed" dependent upon the platter speed and the distance of the styus from the spindle. The ins and outs of the groove walls however cause rapid instantaneous changes in stylus velocity, in order for it to negotiate the groove. Each instantaneous change, because it forces a change in velocity at the stylus tip, is an "acceleration". Acceleration is defined as a change in velocity, up or down. So now you have a mass (the moving mass of the cartridge) that is constantly accelerating. This would create or rather require the stylus to endure tiny forces according to Newton’s First Law of Motion (F = ma). It is those tiny Newtonian forces, which have a vector direction in the general direction of the friction force, that add to the net skating force.

Then could you explain why if you put the stylus on a glass platter or blank vinyl disc, neither of which have a tortuous groove, the skating force still occurs ? 

Sure.  Nowhere did I or anyone else say that groove tortuousity is the sole cause of the skating force.  In fact, I think it's a minor factor causing minor ups and downs of the baseline skating force, which is due to friction of the stylus in a vinyl groove. 

Skating force is due to overhang. No overhang, no skating force. That simple. This is why tangential tracking arms have no need of anti-skate. Tracking tangentially generates no skating force. 

Once there is overhang then there is skating force, but only when playing a record. This is so obvious it should go without saying. But someone keeps insisting otherwise. If the velocity is zero, there is no skating force. If there is velocity with overhang then there is skating force. Clearly then skating force is related to velocity. QED.