I have wanted a CNC milling machine for some years now....at first I built my own CNC router out wood, which turned out fine but it could not work on anything harder than wood. Therefore, after a lot of research, I decided to buy myself a manual mill and convert it to a CNC mill. Up to this point I spent at least 400 hours working on it, and I can finally say that the machine is complete. Here are some details about it:
1) Closed loop driver motors on all axis (NEMA 24 on X, Y & A, NEMA 32 on Z).
2) SFU1605 ball screws, C7 accuracy grade. Backlash is not too bad, fortunately I can compensate via software.
3) PlanetCNC 4 axis board.
4) Vertex rotary table with a self-centering 4 jaw chuck.
5) Self-machined aluminum mounts for motors and screws on all axis.
6) Wood and plexiglass enclosure, to keep the chips inside and the workshop clean.
7) Coolant system, to provide better chip evacuation, lubrication of the endmill and part cooling.
8) Endstop switches for machine homing and tool-offset sensor to speed up tool changes.
9) 2 self designed relay boards that handle the start and stop of both compressed air and spindle.
10) Vanturi vaccum pump system powered by a compressor, which allows me to use custom made vaccum jigs to hold the parts during milling.