Homebrew_PCBs

This is the one I was referring to:

https://sites.google.com/site/pjoptical/home/centering-microscope

Also check out:

http://www.chaski.org/homemachinist/viewtopic.php?f=24&t=97737&sid=5b8aa66990aab263ec5027ae7d0f1378

(You may have to copy and paste the above link into your browser for some reason it doesn't work for me from yahoo groups)

Much of the same information is also here:

http://joyofprecision.tumblr.com/tagged/toolmaking

And, Google Books - Popular Science Jan 1949 pg. 226:

https://books.google.com/books?id=YyQDAAAAMBAJ&printsec=frontcover&dq=Popular+Science+Jan+1949&hl=en&sa=X&ved=0ahUKEwit-5nXh5vLAhVCbz4KHfM6C04Q6AEIHDAA#v=onepage&q=Popular%20Science%20Jan%201949&f=false

Hemingway Kits has a kit available:

http://www.hemingwaykits.com/acatalog/Centering_Microscope.html

I doubt this is very accurate but may be simple to make and fit some needs:

http://swarfrat.com/MillSpindleCenteringScope.htm

This is the sort of thing I think 3-D printer would come in handy for. That is, for fabricating some of the parts. But, not having experience with one I may be wrong. I would be interested in hearing other people's opinion on this since building a 3-D printer is one of the projects I have in mind.

Craig