That's an excellent question. The whole idea of using Vias on the PCB is to have the pcb manufacturer to tin the wall of those 6 holes. I guess the plan is to secure those precision R2 copper balls with solder paste from under the PCB. That way I can hot-air gun the kit and precisely adjust those balls on the flat granite table. A friend recommended me to drill the 6 balls (?!) and attach them to the body of the probe with a set screw. I doubt I'll go this/his route as thermal exp would ruin this sort of set-up overtime. If you have any suggestions by all means, now or soon could be a really good time to share your ideas... I'm just about to send over the gerber to my pcb mfg and run these solids in the lathe ;-)
Understand this is not a final design; more or less a proptotype to validate the data I've pulled out from several thermal, linear & non-linear analysis. Once I have this proto in hands, and validate how it behaves I'll re-do it with fatter this & shorter that, etc...
@mactec54 - I'm doing the smallest 3D Probe in-the-World! Will crunch out 1um or less when done
I appreciate the link up, unfortunately the advertised probe is way too big for some of the parts I'll have to angle & scan on my table.
ps. quick preview of what came out from the cad side so far. I'll resume this tomorrow and hopefully turn a prototype this coming weekend - if the weather is bad and worth hiding in the shop lol