Current Recommendations On Home Wheel Alignment Equipment?

92b said

Yes, I understand that caster is calculated. I don't know the formula for calculating caster from caster swings though. I guess I should have asked Rusty how he was "calculating" caster with the tools he was using. I did fabricate a tool to measure caster directly for a project I was doing.

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Easy. The complication comes when you get away from the "common" measurement with the wheels "in" and then "out" at 20 degrees from straight ahead. You take camber (tilt) readings at those wheel turn angles, subtract them, and then multiply by 1.5. That is your caster. If you for some reason do not or can not turn the wheels 20, then you'll have to search up the formula for different angles. It's just not that hard.

Main thing is to make sure the suspension is "jounced" and is not "bound up" (which actual turning plates help take care of, that you actually turn the wheels fairly accurate to 20 degrees, and of course that you are actually measuring wheel camber (tilt) fairly accurately. For example, whatever you use for a tilt guage or even a real caster/ camber gauge IT MUST BE ROTATIONALLY PLUMB If you look at most any of these, they have a "to front and to rear" level bubble to level the gauge in that direction.