Ralph, I am saying that when the cantilever/stylus is tangent to the groove, the friction force generated by the stylus to groove resistance has a vector directed tangent to the groove, too. But because the headshell is offset with respect to a straight line drawn from the cantilever to the pivot, there will still be a skating force due entirely to the headshell offset angle. Interestingly, if you use an "underhung" tonearm (no off color pun intended) with zero headshell offset, then there can be only one null point on the surface of the LP with respect to tracking angle error, but at that one null point, skating force will also be zero, because the forces will line up with the pivot.
What is more accurate: magnetic anti-skating, or barrel weight attached a fishline?
I have seen turntables from Project, Music Hall, and a few other brands that still incorporate a small barrel weight attached to short fishline string which is stretched across a hooking loop to set ANTI-SKATING. It seems to be an artifact from the 1960's and 1970's tonearm design. It is also easy to lose or break
My question is how accurate is that "device" compared to magnetic anti-skating employed by many turntable manufacturers Thank you