- Print the parts from the STL files (choose the holder you want: with holes to insert the pins snugly or without if you want to glue them (other than 3mm) - Cut 3x 3mm drill bits to use the shanks as contact pins (length 13mm) - Make the PCBs (I milled mine, but etching would be fine as well). - Find some springs - Find 6x 4mm steel balls (I got mine from Conrad Electronic) - Solder two wires on the PCB (in the "C" areas is easier) - Assemble - Connect to your CNC input - Enjoy ! -To adjust how vertical the probe is, slightly unlock the 3 nuts on top and turn the 3 screws until you get the right position. Then tighten the nuts again. I use an old 3,2mm mill bit as stylus, it works quite well. This design requires no soldering on the steel balls. The parts are printed but can be done with conventional machining tools (lathe, drill press). In the Zip file you will find all my source files (Solidworks) and also the Galaad files I used to mill the PCBs The parts represented as small tubes are actually the springs.