On Tuesday, in article
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[email protected]>
[email protected] "Liam" wrote:
> Does anyone know what the tracking should be set to on a series 3, the
> manual says 1.2 to 2.4 mm but my gauge reads in degrees. How do I convert
> the measurement to degrees.
Simple trigonometry, though you need to know how far from the hinge-
point you take the measurement at. Wheel rim, isn't it?
Anyway, let's say that the rim is 400mm across. That's one side of the
triangle. I'm assuming that 1.2mm is the difference between front and
back, but is it the total for both wheels?
I'll stick to the math.
1.2mm divided by 400mm
Hey, 1.2mm at 400mm is 3 milliradians
There are 2pi radians in 360 degrees. So 57.3 degrees to a radian.
57.3 degrees multiplied by 0.003 radians
0 degrees, 10 minutes, 19 seconds.
For these small angles, double the distance is double the angle, and
vice versa. As long as you have both distance and angle measuring the
same thing -- one wheel or both wheels -- and aim for the middle of the
range, that should be near enough.
If you've heard of stuff like sines and cosines and tangents, don't
worry. For this sort of small angle, the differences don't matter.
Radians are based on measuring along the arc of a circle, rather than a
right-angled triangle, and you'd need a very sharp pencil to see the
difference in a drawing.
--
David G. Bell -- SF Fan, Filker, and Punslinger.
"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."
