Do 45 RPM records need higher anti-skate setting?

"(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.

Mmakshak,
There is actually a logical default position: namely, that given there is a skating force (which is old, proven, science, well documented, though commonly misunderstood) and which leads to VTF being different on each channel, it should be counteracted.

it is approximately between a fifth and a third of the VTF, depending on stylus profile and other factors.

Now, while it may vary subtly to some debatable extent across the record and with platter rpm, it is, as Omsed stated, always there and always towards the centre. Applying anti-skate may or may not be audible, but it is designed to compensate for something which could result in record or stylus damage, which is why 99.9% of arms have it in some form.

Users seldom use VTF below cartridge makers recommendations, because the cartridge will mistrack and even if you can't hear that mistracking it is acknowledged as being a bad thing.

However, without anti-skate, the chances are that your cartridge is running below recommended VTF on the right channel.

John

Timeltel
you said:

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?

That depends on the friction generated. All things equal, the friction would be more or less the same, as once the stylus is moving the friction (dynamic as opposed to static) is constant if nothing changes. It is is like when you try to push a heavy box. Static friction makes it hard to get started, but once it is moving it takes more or less the same effort whether it is moving slowly or quickly ). And it is the friction which supplies the force to rotate the arm.

However in any particular modulated groove, the friction changes with velocity (due to the modulation). So in the case of the OP, there may have been a particularly loud passage which indicated that the the existing anti-skate setting was inadequate.

John