Do 45 RPM records need higher anti-skate setting?

Regards, Omsed: Let's clarify the difference between centrifugal and centripetal force. Centripetal force is ANY force that acts to prevent an object from moving away from the center of an orbit, see http://www.diffen.com/difference/Centrifugal_Force_vs_Centripetal_Force.

Consider skating phenomena the consequence of two forces acting upon the TA. First, friction along the axis of the TA. This is relative to grove modulation or any stylus "drag" in an unmodulated groove, or even an un-grooved disc.

Any TA (with under or overhang) will be subject to a second vector, this is tangent to the long axis of the TA, and, dependent on wether the stylus is under or overhung relative to the spindle, will exert a lateral force on the stylus. The TA will be inclined to move either away (underhung), or towards (overhang) the center of revolution. The groove constrains the TA movement and serves as a centripetal force.

These actions are observable and repeatable, the same principles that guided Sir Isaac, who also gave definition to centripetal force.

The question remains unanswered, would not a TA tend towards the center of an un-grooved disc more rapidly if spun at 45rpm rather than at 33.3rpm?

Peace,

Omsed,
No one is talking about spinning a complete turntable, or that there is a centripetal force involved in the skating issue, or that the cartridge is spinning with the record. If you read all the posts here and elsewhere I think that is clear. The only reason for using the term at all is in attempting to try and clarify the difference between a force acting toward the centre in the context of an arm being spun or a body in orbit, and a force acting towards the centre in a tonearm in reaction to the friction in the groove.

VTF is, of course, different on each groove face unless anti-skate is used. That's why the skating force is a problem. That is elementary. I don't get what you are saying re the groove faces being identical etc. We are not talking about record cutting, but playback.

Regarding information storage, if I store the same information in a bigger space, that's all I have done. When I retrieve it, I get it back. The point about the bigger space is that I can store more information, otherwise what's the point? Perhaps I am wrong, not being a recording engineer, but I was under the impression that higher speed allowed higher levels, whether it be tape or vinyl. And if there is more information, of whatever kind, the cartridge has to do more work to retrieve it, hence the reference, albeit imprecise, to energy (I take your point about the irrelevance of the platter's kinetic energy).

As you are having difficulty finding proper scientific papers, I've posted a link here. Look at Gilson and Alexandrovitch.

John
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Timeltel,
As Omsed said

Skating force remains the same since it is based solely on the magnitude of friction and the offset angle of the tonearm. Same tonearm, same friction, same skating force, so anti-skate should remain the same.

However, if the friction force changes then so does the skating force, so it depends on whether the coefficient of friction remains constant, which is an assumption.

For an ungrooved as opposed to grooved disc, I don't know. For what it's worth, my experience of records skating (mainly in days long gone by) is that I recall them skating at much the same speed whether 33, 45 or 78, judging by the pitch of the scratching sound...

John
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Regards, John Gordan: As always, a pleasure to have your informed opinion. I do need to correct my first para., most recent post. Centripetal force *opposes* centrifugal force, to what degree is a variable.

Peace,

There is no such animal as centrifugal force. It is fictional. Any object in motion will tend to remain in motion in a line determined by the vector of the force that set it in motion. This is Newton's First Law, and the following is from Wikipedia:

"This is known as uniform motion. An object continues to do whatever it happens to be doing unless a force is exerted upon it. If it is at rest, it continues in a state of rest. If an object is moving, it continues to move without turning or changing its speed. This is evident in space probes that continually move in outer space. Changes in motion must be imposed against the tendency of an object to retain its state of motion. In the absence of net forces, a moving object tends to move along a straight line path indefinitely." (Let me add here that this is true in the absence of gravity and friction.)

To keep an object in circular orbit, one must apply a force directed inward toward the center of the orbit. This force vector is centri-petal, "center-seeking". Think of a sling shot. Before release, the stone travels in a circle because the sling allows you to apply a centripetal force. The moment you let go of the sling, the stone flies off in a line tangential to the radius of its orbit, because that's the direction of the force vector that motivates it. If there really were any such thing as "centrifugal" force (center-fleeing), then the stone would fly away in a line parallel to the radius of the orbit. That does not happen. If David had not understood this, Philistines would rule. He would have missed Goliath by a mile.