Do 45 RPM records need higher anti-skate setting?

Dear Omsed, This is not a university class or a peer-reviewed forum. Anyone is free to contribute in any way he or she prefers. I can say for myself that when I try to explain something, I am in essence stating my own reasoning of the problem for the express purpose of receiving criticism or correction. I want to learn. Here, I take exception with two of your claims:
(1) Overhang DOES have something to do with the skating force. Because of stylus overhang, the stylus can never be tangent to the groove. That is the root cause of the skating force, because the force of friction is always tangent to the groove. Thus a force vector is created with a direction toward the inward path of the tonearm (the real force is not along the arc of the tonearm, but is inward) that in its net expression becomes the skating force. It also would appear that the offset angle plays a role in determining the direction of the force vector created by lack of tangency, the radial expression of which is the skating force. (Perhaps this is not clear, would need a diagram to demonstrate.)
(2) No one is arguing with your statement that vertical and horizontal movement of the stylus creates the electrical signal that is converted into sound. The point made by me and others was that those vertical and horizontal wiggles that the stylus tip has to trace whilst the linear velocity past the stylus remains constant might in effect alter the coefficient of friction between stylus and vinyl, transiently and variably, so as to contribute to variability in skating force. I am not at all sure that this is a real issue, but it is not nonsensical to contemplate it. And having posited these things, it then would seem possible that a 45, if anything, might induce less skating force than a 33, given that the exact same music is recorded on each. This could certainly be incorrect. Have you measured such phenomena?

By the way, are YOU a physicist? What is your background in what science? I am guessing you are an engineer.

Friction=skating, that's it. I remember back in the 70s some stereo shops had blank LPs for setting anti-skate. They would adjust the anti-skating on the tonearm until it would stay in the middle of the blank record.
45 rpm LPs can have a higher dynamic range, if the recording engineer chooses to apply it. The higher linear speed affords more velocity to be transmitted to the stylus. That means tracking ability of the stylus is further challenged and since the forces are or can be unbalanced a bit to the skating side of things, the first sign of mis-tracking is likely to be heard in the right channel. My 45 rpm direct to disc of the Apassionata can attest to that. My Benz can track it perfectly from beginning to end; but the stylus has to be squeaky clean.

Omsed: I am hoping that you do not become disenchanted with the students in the front of the room who are poking you during your teachings. I am the quiet student in the back who is soaking up as much as I can from you. Keep it up as long as you can bear it.

Hmm. So I used a pencil & fixed a plastic headed straight pin at each end. Let's call the "pivot" proximal, the other, the unconstrained end, "distal". Held the "pivot" pin and placed the other on a Boston Audio Mat2, the plastic pin heads depending from the beam. In a condition described as "overhang", the pencil "beam" was center seeking. As OH was diminished speed of travel also diminished. In a condition of "underhang", the end distal from the crude "pivot" came to rest further from the center of rotation, a state of "equilibrium" was observed. As "underhang" was increased, the distal end eventually ran entirely off the edge of the Mat2.

Running the "pivot" against a straight edge, it seemed to me that the beam remained parallel to its previous location and also seemed to maintain a 90* angle to the guiding straight edge. Movement at point "A" resulted in an equivalent movement at "B" in a most linear fashion.

It also appears these various movements occupied a smaller time-frame as speed of rotation was increased.

'Fraid I lack the background in Physics to prove these actions.

Peace,

Rtilden, you surmised correctly that I did not want to respond, it's not worth it. I have graded students that have been sure they have been right until I drew a free body diagram showing all the forces balance, in front of them, and verbally went through it. Then in real time when they offer up their view, I can in real time show the mistakes. This is not feasible in a thread on a forum where you cannot include drawings such as a free body diagram with a vector analysis.

I also realize that I was wrong in thinking everyone wants to learn. Some would just as soon remain ignorant, as long as they can convince some others they are right.

Thanks for your note!

So, over and out for me. Thanks much for your note though.

I have a device which can show the actual side-forces imposed on the cantilever. Although the instantaneous side-forces are affected by groove drag (and therefore groove modulation), it appears to me that the general side-forces experienced by the cantilever follow the tracking distortion curve.

hth

45s are NOT cut with greater modulation (if they were the sound would be louder through the speakers), the goal of the mastering guys is same volume, so the idea that different anti-skate is required is far fetched. Same anti-skate.

I have quite a few 45s that are obviously cut at higher levels. IOW, they play louder. Also, when we cut at 45 on our lathe (I run an LP mastering operation, FWIW) we find that we can cut certain frequencies at higher levels easier than 33. I think where you are having a problem is the assumption that the 'mastering guys' are going for the 'same volume'. We might and we might not. Usually we cut with two goals:

1) see if we can get it all on the side and
2) don't over cut such that the stylus gets knocked out of the groove or the cut goes over the previous adjacent groove.

Its pretty well impossible to overload the cutter system- the main limit is cutting a groove that a cartridge can track without distortion. A lot depends on the signal that is being recorded and they are not all the same else the planet would be a boring place :)

So if friction due to modulation is indeed a factor in skating forces, it would be a mistake to assume that it will be a constant- IOW it is indeed a variable.

While all these discussions are interesting, can you see if one of these ideas or thoughts are incorrect, or are left out, your conclusions will be wrong-sometimes incredibly so.  Lost in all this is how I actually set my anti-skate, and it didn't have to do with the beginning of a record.  It had to do with the end of the record-which turned out to be a compromise.  I could not use the setting that made the end of the record sound its best(I had to use a slightly lower skating force than that, in order to get the best sound over the entire record.).  Some assumptions(that cartridge manufacturers had arrived at recommended levels of anti-skate for their cartridge correctly, and that the anti-skate gauge was correct[or I read, from real life experiences, that it wasn't.].  See omsed's remark about lawyers and doctors.) had to be made by me.  Because so many people on Audiogon disagreed with cartridge manufacturers' anti-skate recommendations, I postulated(with some research on what arms these people were using) that anti-skate settings for unipivot tonearms might be different from the manufacturers' recommendations(which may have been based on gimballed tonearms).