Need help building a stylus with movable components

[[Da...]]

Lots of questions here...thank you in advance!

When building a stylus with movable parts, what is the trick to getting the movable parts at the correct angles? And how critical is it?

I am building the stylus pictured. It can be rotated 360° (blue arrow) and the knuckle can bend back and forth as well (green arrow). 

Let's say that when the RDS is at 0°/0° I want the stylus to face forwards towards me and be lifted up 45° towards me.

How do I ensure that it is exactly centered / forward and exactly 45° up? What if it is not exact? How far away from that can I be before it creates an issue?

What angle does the reference sphere have to be at in order to qualify it without a collision? So far our reference sphere has always just been straight up. 

If I have to change the angle of the reference sphere, how do I ensure it is at the correct angle?

When I go to qualify it, if it does the thing where it guesses what angle the probe is at, but it's not what I intended, do I change the values to match what I intended, or do I adjust the stylus and try again until it matches?

I believe once it is set up, I could set it up as different probes with different A angles, correct? But the B angle would always be 0° and the probe would always be 45°. Is that correct?

What if in the future I wanted to use this same set up but have the knuckle point the probe at 30° rather than 45°. I imagine I would need to create a whole new stylus system, correct? But wouldn't that require a separate adapter plate so that the CMM would recognize whether it was the 30° setup or the 45° setup? Would it make more sense to leave this one the same and buy an identical setup and make a whole new configuration?

 

[[Ch...]]

Here's what you do to find the exact angle.   Start touching the shaft of the probe against the reference sphere.  Make sure to get points high and low on the shaft and go all the way around the reference sphere.  Your goal is to create a cylinder feature inside of Calypso.  Your A1 A2 angles on the feature are the angle the probe is angled.  You then enter these values into the appropriate spots in Calypso when you qualify it.    

[[Cl...]]

A machinist protractor or an optical comparator also work well.

[[Ri...]]

Get one of these, they are inexpensive and can aid in setting any simple or compound angle you need.

[[Ze...]]

Optical comparators work great for this. Zeiss also makes something called FixAssist that aligns things for you.