On Fri, 16 Nov 2018 18:52:27 -0000 (UTC), arlen michael holder wrote:

As an aside, it's always the people who have never done such things who
blithely proclaim all sorts of "googled solutions", which, is kind of funny
in that the less someone knows of the problem, the more so-called
"solutions" they can find on the net.

BTW, since I do all my own mechanical work, that means I do my own
suspension alignment (you know, camber, caster, & toe, X, Y, & Zed).

The measurement of X, Y, and Zee aren't difficult using cellphones, which
have the required accuracy for angles, and the adjustment of the bolts is
trivial, where toe plates and camber jigs help.

What's difficult s the MATH involved.
It makes your head explode.

Not because trig is difficult mind you, as trig is trivial.
Only someone who has done their own alignment would understand why I say
the math makes your head explode - which is where a cellphone app could
play a key role in simplifying things.

You see, what you measure at home for an alignment is NEVER what the spec
actually is. Why? I can't tell you why. I can just tell you that it is.

For example, my bimmer has toe spec'd in degrees, but, at home, you
typically measure toe in inches, not in degrees ... simply because it's
trivial to measure toe in inches at home to the desired accuracy.

Yet, most American cars (thankfully) spec toe in inches (which, for once,
makes sense), but of course, it's often inches to centerline, where you
then have to figure out what they define as the centerline (which can be
different on every vehicle).

For camber, at least you get a spec in degrees, but you can measure camber
in inches using just a plumb bob and a ruler, so again, you have to convert
(using basic trig) from inches to degrees.

Meanwhile, you compute caster from other measurements.

The point is that (a) each vehicle is different in how it differs from (a)
the specs it gives you, and (b) the specs you can easily measure at home.

All the work is NOT in the measurements (measuring camber and toe to the
required precision and repeatability is trivial for example) nor is there
any work in the adjustments (twisting a bolt is easy, and even easier to
replicate the normal position of the vehicle with niceties like toe plates
and camber jigs).

All the work is in the math.
That's where an app that measures angles and which can take as input
inches, can be a wonderful app that, to my knowledge, doesn't exist yet.

Does anyone here know of such an app for example?