@lewm
I referred to the headshell offset angle as an angular error, because it IS an angle and it DOES create an error in terms of its contribution to creating a skating force
Indeed, but the tracking error it causes is far smaller than the headshell offset angle itself, so it should not be called the offset angle error because it isn’t!
Without detracting from Lofgren’s work in 1940, I mentioned Percy Wilson’s pioneering work. His analysis and equations were published over 100 years ago in The Gramophone magazine, September and October 1924 issues. This is generally regarded as the first calculated solution including overhang, offset angle and null points popularised in the English language, but there is a preceding French patent filed in 1907 by Hungarian merchant Bela Harsanyi - well before stereo and electrical recording.
@elliottbnewcombjr
With a pivoting arm, there is NATURAL (someone else explain it, somewhere else) inward skate on a GROOVELESS surface, The anti-skate is NEEDED to counter the amount of skate
I used the word ’groove’ to denote a direction. which a groove-less surface does not define. Both groove and groove-less surface exert friction but is a long bow to assume the friction is the same!
The friction-induced force is always vectored along the direction of the groove (ignoring the wiggles). I believe @lewm uses cantilever to describe the same direction though cantilevers do change direction slightly depending on the antiskating force applied.
Forces can be broken down into components using vector analysis, in this case into a component from the stylus to the pivot, and another at right angles - which pulls sideways and is the skating force.
I did think of starting a separate thread comparing Vertical Tracking Angle errors to Horizontal Tracking Angle errors. Maybe I should. So far, nobody here has challenged my analysis, which in summary suggests that a well-set-up pivoted tonearm has HTA errors equivalent to an 8-mm change in cartridge height during play of a 12" record side with a 9" arm. 8-mm is a lot of shims