Reed 2G magnetic antiskate

@elliottbnewcombjr 

totally agree. And, to my small brain, these

line contact styli, as they fit down far into the groove

with lots of symmetric wall contact, skating forces or much kess

than with older tips with little wall contact

lewm, others

What/whom do you consider reliable source(s) regarding anti-skate?

It does seem like WAM is capable of precise measurements and calculating averages, so as a source of info I feel comfortable quoting them as a reliable source, and yet, they are ’caught in their own loop’, and it’s easy for me or others to ’get it wrong’. 

NOTE: WAM wants you to measure your arm’s inherent horizontal friction with zero outer force applied, that way you know about your arm before you start adding any anti-skate force!

They say a typical 11" arm has an average of 2.46  degree error due to friction. (I noted that he said degree error, not % of ____ error ____?)

Now, when you use WAM’s tool, it is measuring the combined horizontal outward force that your arm and it’s anti-skate mechanism is applying, to the end of the arm, a bit in front of the stylus tip, at any specific location on the radius of the arc of stylus travel, suspended 2-3mm above the LP. IOW, it is not measuring inward or outward skate.

In the prior anti-skate thread, OP said no anti-skate force was needed, (presumably WAM’s tool would have measured that) and I have mentioned my problem with ’wire pushback’ on my re-wired Blackbird arm and some of us know how VPI relied on a twist in the tonearm wire to cause enough anti-skate.

jw944ts OP

"totally agree"

NOOOOO, I posed the question only, I suspect the answer is that there is no difference in the amount of total friction, if so, there would be lots written about it.

X amount of friction is still X amount, even if distributed over a larger area. Nothing's pure, we are in a groove going this, that and the other direction, but friction is friction I suspect, directly related to Vertical Tracking Force they say.

...dont you just LOVE this stuff??!

I can think of a way in which stylus shape may make a difference to friction in the groove.  Friction force is equal to a factor called the coefficient of friction, mu, multiplied by the Normal Force.  Mu is different for any two substances in contact. Normal Force means the force perpendicular to a surface.  When a stylus tip rides in a groove, it is touching both groove walls. But the force vector due to gravity (VTF) is perpendicular to the surface of the LP, directed straight down toward inverted apex at the bottom of the groove.  The vector component of VTF that actually presses against the vinyl perpendicular to the slanted wall of the groove is always going to be less than VTF by the factor of that angle of the slant or slope of the groove.  On the other hand, since we have two contact patches, one on each side of the groove, the net friction is multiplied by 2. So the friction that causes skating is mu*2(sin of that angle)*VTF. I guess the angle can be different based on the stylus shape. Furthermore in actual practice the stylus is riding up and down in addition to moving in the groove, or so I am told.