<VV> alignment tool question

[Craig Nicol]

Anyone remember how to work the old Bear magnetic caster/camber alignment
gauges?  I have a nice pair but the instructions that came with them apply
to a different model with different scales. This tool has three leveling
vials on the top and a bubble vial on the bottom.  More or less, the upper
vial is SAI., the left vial is for camber and the right vial is for caster.
What's confusing is the use of the "Camber correction" and "Caster
Correction" scales.

 

Specifically:

1) The left/right scale at the top is labeled for "Steering axis
inclination" and "Camber Correction".  What do I do with the "Camber
Correction" scale and when?

 

The Camber scale (left parallel vial) is obvious.

 

2) The right parallel vial scales are labeled "Camber Correction" and
"Caster".  When and how do I use the "Camber Correction" scale?

 

3) On the underside of the tool, there's a bulls eye bubble.  Is this for
leveling the left/right SAI scale to zero for easier SAI and Caster
measurement?

 

4) For Caster measurement, some of my info indicates that you set the front
wheel to 20-degree turn-in, level, move to 20-degree turn-out, level, and
measure.  Other info indicated that you start at turn-out and move to
turn-in.  Does this vary according to the mfr of the tool?  What's the right
way for the Bear tool?

 

Thanks in advance,

Confused in Idaho,

Craig Nicol