Higher mass arm

[analogadikt]

The accepted wisdom is that skating force reduces as the stylus travels inward. That is what I have read on various forums. Do we believe that Garrard designed this mechanism without extensive laboratory tests? In fact Garrard went ahead and designed a magnetic system that produced identical reduction in force without any physical contact. That system was incorporated in the ZERO100 tangential tracker tonearm. They took patents for these ( also the synchro-lab motor) and the designs were licenced to other manufacturers. The pivoting weight a/s system can be seen on some Jap tonearms.

I read recently ( sorry, can't remember which site) that the force is at its greatest at the outer grooves, reduces at the mid-point and increases again( but less than the outer groove position) at the inner grooves.

Anthony (Flood2) has made that remark in another topic here. This is first time in eighteen years of forum browsing that I have come across a comment that the skating force again increases at the inner grooves.

Regards,

Anwesh

[stratokaster83]

The accepted wisdom is that skating force reduces as the stylus travels inward. That is what I have read on various forums. Do we believe that Garrard designed this mechanism without extensive laboratory tests? In fact Garrard went ahead and designed a magnetic system that produced identical reduction in force without any physical contact. That system was incorporated in the ZERO100 tangential tracker tonearm. They took patents for these ( also the synchro-lab motor) and the designs were licenced to other manufacturers. The pivoting weight a/s system can be seen on some Jap tonearms.

Anthony (Flood2) has made that remark in another topic here. This is first time in eighteen years of forum browsing that I have come across a comment that the skating force again increases at the inner grooves.

Regards,

Anwesh

Anthony is absolutely correct in that regard, the skating force is mainly a function of the angle between the groove tangent and the stylus to pivot line. This means that it's highest at the outside of the record, gradually decreases towards the middle and then starts increasing again, but never to the same levels as at the outside radius.

Some early Sony tonearms (e.g. PUA-237, PUA-1500) had a cam in their antiskating mechanism that was supposed to produce the inverse of that force curve. I don't know whether this predates the Garrard patent.

[chas b]

The accepted wisdom is that skating force reduces as the stylus travels inward. That is what I have read on various forums. Do we believe that Garrard designed this mechanism without extensive laboratory tests? In fact Garrard went ahead and designed a magnetic system that produced identical reduction in force without any physical contact. That system was incorporated in the ZERO100 tangential tracker tonearm. They took patents for these ( also the synchro-lab motor) and the designs were licenced to other manufacturers. The pivoting weight a/s system can be seen on some Jap tonearms.

Anthony (Flood2) has made that remark in another topic here. This is first time in eighteen years of forum browsing that I have come across a comment that the skating force again increases at the inner grooves.

Regards,

Anwesh

It is mentioned in this article https://www.analogmagik.com/antiskate( this isn't the article I was referring to earlier but I'm struggling to find that one).

[chas b]

And here. https://www.wallyanalog.com/post/skating-and-anti-skating-force-myths

[Machines 4 Music]

........in which case, the AS in question is working the wrong way round. The counterforce it is applying is REDUCING as it approaches the inner part of the record as the AS weight is lifting with a shortening radius.....or am I missing something?

AS varies across the surface, but is higher at the outer edge, and reduces towards centre (or the middle, then increases again in some schools of thought). The weight starts just above horizontal, approaching vertical (but not getting there) towards the centre. It's a compromise, and this approach can never be correct across the whole surface.

[low pitch]

To put a number on it I calculated the percentage change in the skating moment caused by a 2 degree tracking error, for my 12" Bokrand TA (343 effective  length, 16.1 degree offset.)

This worked out to be 12%