If you are going to be insulting...
This is Mechanical engineering statics 101. The ME equivalent of Ohms law.
The sum of the forces and the sum of the torques at every point in the assembly has to sum to zero. It is not complicated. Work it out for yourself.
I'm done here.
This is Mechanical engineering statics 101. The ME equivalent of Ohms law.
The sum of the forces and the sum of the torques at every point in the assembly has to sum to zero. It is not complicated. Work it out for yourself.
I'm done here.
Tonearms are pretty easy to build. I suggest you build it and try it to see if the novel benefits actually materialize.
Nope, it wont work.
You can shape the tonearm whatever you want, but what counts is straight line from horizontal pivot to stylus tip. If that line isnt tangential (and it isnt) to record center you will have skating.
You can shape the tonearm whatever you want, but what counts is straight line from horizontal pivot to stylus tip. If that line isnt tangential (and it isnt) to record center you will have skating.
The tonearm geometry that minimizes tracking angle error across the disc cannot avoid skating forces, if there's one pivot, because the pivot placing is fixed by the need to minimize tracking angle error. All you can do with a single pivot arm is lengthen it - infinitely long arm would perform perfectly!!
Or put another way the shape of the tonearm doesn't feature in the equations of motion at all, only the distance between stylus and pivot, the angle the head is mounted relative to the stylus-pivot line, and the length of that line. Practicalities suggest a relatively straight tonearm to avoid unnecessary forces on the pivot bearings. This also simplifies analysis of the vibration modes of the arm and minimization of arm mass too.
Or put another way the shape of the tonearm doesn't feature in the equations of motion at all, only the distance between stylus and pivot, the angle the head is mounted relative to the stylus-pivot line, and the length of that line. Practicalities suggest a relatively straight tonearm to avoid unnecessary forces on the pivot bearings. This also simplifies analysis of the vibration modes of the arm and minimization of arm mass too.
How a pivoted tonearm works? It can be best understood by vector decomposition of the stylus drag force. The stylus drag force is caused by the friction between the grooves and the stylus, as the disc rotates. This force is tangentional to the groove by nature. It can be decomposed to two perpendicular force vectors; the vectorial sum of these forces make up the drag force. One force vector points to the (horizontal) pivot where an opposite force prevents the arm move in this direction. The other force vector points to the center of the disc, and an opposite force acts at the groove wall, preventing the inward move that would rotate the arm around the pivot point. This force vector can not be avoided at a pivoted overhang tonearm, it can be only cancelled by some kind of antiskating device. The shape of the tonearm is irrelevant, it serves just as a rigid structure between the stylus tip and the pivot point.
The answer is not to angle the cartridge and to move the pivot point during play. There are an infinite number of paths the pivot point can follow to accomplish this, both straight and curved.
@diyrayk
Best troll pic I have seen!
More seriously - what is the real advantage of such a contrived design?
Best troll pic I have seen!
More seriously - what is the real advantage of such a contrived design?
Hi,
doesn't the sketch remind You of Dynavector's DV505?
They didn't claim it to be free of skating since they knew it weren't.
Distributed horizontal and vertical pivot points may lead to different behaviour for example with warped LPs .... which is a 'vertical' problem.
For the 'horizontal' problem of skating the position of the vertical pivot is irrelevant.
jauu
Calvin
doesn't the sketch remind You of Dynavector's DV505?
They didn't claim it to be free of skating since they knew it weren't.
Distributed horizontal and vertical pivot points may lead to different behaviour for example with warped LPs .... which is a 'vertical' problem.
For the 'horizontal' problem of skating the position of the vertical pivot is irrelevant.
jauu
Calvin
Since the mass of the main arm is off centered from the horizontal pivot, you can intentionally tilt it ever so slightly away from the spindle to create an anti-skating force to the right. Frank Schroeder implemented that scheme in his ALTO arm. Leveling of turntable platform becomes very important.
Geometrically, it is no different from a conventional pivot arm with offset headshell. Just draw a straight line from stylus tip to pivot point. It's still a straight line... just like most other pivot arms.
Geometrically, it is no different from a conventional pivot arm with offset headshell. Just draw a straight line from stylus tip to pivot point. It's still a straight line... just like most other pivot arms.
Does it pivot at the right angle in the arm? If not, you can put any shape you want
between the stylus and the main arm bearing and it will make no difference except
to add mass - which you don't want.
G²