Mini Mill Dro | The Hobby-Machinist
HARBOR FREIGHT, CENTRAL MACHINERY & BUSY BEE . Mini Mill Dro. Thread starter WMello; Start date Jul 11 ... Recently I've finished a DRO for the Mini Mill using the Arduino microprocessors. It uses iGaging scales on the X and Y axis, Quad Encoder on Z axis and infrared emitter/detector for the RPM.