Hi Mark,
Interesting question. To attempt a meaningful answer we must think about the two forces in question, skating and anti-skating. Let's consider skating first.
Skating force is a function of headshell offset angle on a pivoting tonearm. Assuming the cartridge is properly aligned (i.e., cantilever tangent to the groove), friction from the (moving) groove pulls directly down the line of the cantilever. Aside from in-groove modulations, which presumably balance out L vs. R in the long run, groove friction alone puts no lateral pressure on the cantilever.
Skating force occurs because the cantilever is not aimed at the tonearm's pivot point. Since the cantilever is aimed inward relative to the arm, from the tonearm's POV any pull down the length of the cantilever will make the arm want to swing inward.
Example: Hold your right forearm out straight in front of you, index finger pointed straight ahead. Tug on your fingertip; which way does your arm want to swing? Answer: neither way, because this "tonearm" has no offset angle. Now angle your wrist so your hand and index finger are pointed off to the right. Tug on your fingertip; which way does your arm want to swing? Answer: to the right, because this "tonearm" now has an offset angle.
Followup question: comparing each of the above experiments, how much difference was there in the lateral force being applied to the FINGER. Answer: except to the extent your arm resisted being swung to the right in example #2, there was no difference. In both cases all the force was exerted directly down the line of the finger.
Therefore, except to the extent the tonearm bearings are "sticky", skating force does not exert ANY lateral pressure on the cantilever. Groove friction pulls straight down the line of the cantilever and the tonearm just follows along. The above is true on all pivoting tonearms with offset headshells.
Now let us consider anti-skating. All anti-skating devices currently in existence apply an outward bias or force to the ARMTUBE. Since the outer end of the cantilever is fixed in position in the groove (by the stylus), any outward force on the armtube MUST be mediated by the cantilever and its suspension inside the cartridge.
To use the previous example: point your right arm and index finger as before, offset to the right, but put your elbow on the desk and also touch the surface with your fingertip. Using your other hand, pull your forearm to the left WITHOUT allowing your elbow or finger to move. What happens? Your finger is being stressed laterally and its "suspension" absorbs that force by allowing the inward angle of the finger to increase.
That is how all anti-skating mechanisms work, therefore, all anti-skating mechanisms tend, over time, to cause the elastic suspension in the cartridge to take a set with the cantilever pointing inward. How much of a set and how long before it appears will obviously vary with the amount of AS force applied, the number of playing hours and the nature of the cartridge suspension. But the basic principle does not change.
This is why, IMO, we see more high hours cartridges with inward pointing cantilevers than outward pointing ones. There is no force in a properly set up turntable that will cause an outward set, but causing an inward set is possible.
This provides an obvious caution against using too much AS. OTOH we must use enough for clean tracking of our toughest LP's (music, not test records). Beyond that, every rig is different, every cartridge is different, every listener's ears and listening priorities are different. I use zero AS now because it sounds better to me and because my cartridge, after 750+ hours of loosening up, no longer needed it to track even the toughest passages. That was not true when the cartridge was newer, when more AS and more VTF were required. Due to the ever changing character of elastomers, these parameters will always be moving targets on any cartridge with a suspension. In the end, the only firm rule is to always pay attention to what your rig is telling you.
Interesting question. To attempt a meaningful answer we must think about the two forces in question, skating and anti-skating. Let's consider skating first.
Skating force is a function of headshell offset angle on a pivoting tonearm. Assuming the cartridge is properly aligned (i.e., cantilever tangent to the groove), friction from the (moving) groove pulls directly down the line of the cantilever. Aside from in-groove modulations, which presumably balance out L vs. R in the long run, groove friction alone puts no lateral pressure on the cantilever.
Skating force occurs because the cantilever is not aimed at the tonearm's pivot point. Since the cantilever is aimed inward relative to the arm, from the tonearm's POV any pull down the length of the cantilever will make the arm want to swing inward.
Example: Hold your right forearm out straight in front of you, index finger pointed straight ahead. Tug on your fingertip; which way does your arm want to swing? Answer: neither way, because this "tonearm" has no offset angle. Now angle your wrist so your hand and index finger are pointed off to the right. Tug on your fingertip; which way does your arm want to swing? Answer: to the right, because this "tonearm" now has an offset angle.
Followup question: comparing each of the above experiments, how much difference was there in the lateral force being applied to the FINGER. Answer: except to the extent your arm resisted being swung to the right in example #2, there was no difference. In both cases all the force was exerted directly down the line of the finger.
Therefore, except to the extent the tonearm bearings are "sticky", skating force does not exert ANY lateral pressure on the cantilever. Groove friction pulls straight down the line of the cantilever and the tonearm just follows along. The above is true on all pivoting tonearms with offset headshells.
Now let us consider anti-skating. All anti-skating devices currently in existence apply an outward bias or force to the ARMTUBE. Since the outer end of the cantilever is fixed in position in the groove (by the stylus), any outward force on the armtube MUST be mediated by the cantilever and its suspension inside the cartridge.
To use the previous example: point your right arm and index finger as before, offset to the right, but put your elbow on the desk and also touch the surface with your fingertip. Using your other hand, pull your forearm to the left WITHOUT allowing your elbow or finger to move. What happens? Your finger is being stressed laterally and its "suspension" absorbs that force by allowing the inward angle of the finger to increase.
That is how all anti-skating mechanisms work, therefore, all anti-skating mechanisms tend, over time, to cause the elastic suspension in the cartridge to take a set with the cantilever pointing inward. How much of a set and how long before it appears will obviously vary with the amount of AS force applied, the number of playing hours and the nature of the cartridge suspension. But the basic principle does not change.
This is why, IMO, we see more high hours cartridges with inward pointing cantilevers than outward pointing ones. There is no force in a properly set up turntable that will cause an outward set, but causing an inward set is possible.
This provides an obvious caution against using too much AS. OTOH we must use enough for clean tracking of our toughest LP's (music, not test records). Beyond that, every rig is different, every cartridge is different, every listener's ears and listening priorities are different. I use zero AS now because it sounds better to me and because my cartridge, after 750+ hours of loosening up, no longer needed it to track even the toughest passages. That was not true when the cartridge was newer, when more AS and more VTF were required. Due to the ever changing character of elastomers, these parameters will always be moving targets on any cartridge with a suspension. In the end, the only firm rule is to always pay attention to what your rig is telling you.