The video covers the conversion of a mini mill (such as Sieg, Little Machine shop and many other vendors). The files are available as CC BY 3.0.
Part 1 - conversion of the main mechanics to make it work but far from perfect.
The model at grabcad - https://grabcad.com/library/sieg-mini-mill-into-cnc-conversion-1
Or as fusion / STEP files - https://drive.google.com/file/d/1TlrGAmpKUnPV5zbhUXAa2twQXYZNf7z-/view?usp=sharing
Parts:
00:00 - Why bother?
01:00 - Plans
05:19 - Motor holders
06:24 - X & Y axes
08:21 - Electronics
16:14 - Z axis
20:52 - Z problem
24:12 - Steppers & Mach 3
30:13 - Does it work?
