Do 45 RPM records need higher anti-skate setting?

Omsed, Point taken. Sorry.

John, The tonearm is stationary, resisting the force of friction on the stylus tip which would tend to want to pull the tonearm clockwise in the direction of LP rotation. But I have privately wondered about a tiny centripetal force exerted by the LP on the stylus tip, as the grooves spiral inward. I think it's overcome or negated by the skating force.

Lewm,
If there was no groove, the arm would skate and rotate until there were no forces acting to make it do so, so there would be, for a short while, a "conventional" centripetal force acting on the stylus and arm along the stylus to pivot axis caused by the rotation.

When there is a groove, the inside face restrains the stylus, so there is effectively no such force, because the arm is rotating only minimally (at less than 0.01 rpm), and the stylus has such a tiny mass, that any forces are negligible, and totally overwhelmed by the friction forces by many orders of magnitude.
J

"(Even) if dynamic friction magnitude were dependent upon velocity. Fact is dynamic friction is nearly independent upon velocity."

A pivoted arm with overhang will seek the center of a blank (ungroved) LP. Would it not move towards the spindle more rapidly if the disc were spun at 78 or 45 rpm than at 33.3?

Peace,

While science is a good objective parameter, I suggest that trying out the skating force is the best way to determine the answer. I do not see a consensus among the posters of exactly what the science is. If one assumption is incorrect, all conclusions from that are wrong. Or you could conclude that one of the explanations of skating force is correct, and procede accordingly.

When there is a groove, the inside face restrains the stylus, so there is effectively no such force, because the arm is rotating only minimally (at less than 0.01 rpm), and the stylus has such a tiny mass, that any forces are negligible, and totally overwhelmed by the friction forces by many orders of magnitude.
J
John_gordon (Answers | This Thread)

As a layman, this would most closely resembles my experiences. Well put J.