I have bought an X2 mini mill some months ago, similar to the Harbor Freight mini mill, and would like to upgrade it with one of those cheap chinese digital led tachometers off of ebay, that everyone seems to use on small lathes and mills.
Now, these tachometers require a DC power supply (8 to 23V) but instead of using an external adapter (which would require switching off the tachometer separate from the machine, unplug from socket when not in use as they always burn etc.) I'd rather tap into the existing DC power supply of the machine. I think there must be some DC source to tap into somewhere in the electric box. Maybe someone can help with a wiring diagram or pictures so I know exactly what wires/plugs I may use to power the tachometer.