cartesian coordinate system where the z axis is vertical and pointing up positive up so that the x and y axes lie on a horizontal plane where the x axis is shown as positive pointing u201c out of the page u201d towards the viewer and they axis is shown as positive on the right side of the z axis generally pcb substrate drilling machines perform four functions staging positioning of the pcb substrates to be drilled in the correct x axis location on their moveable table locating the drilling unit in the correct y axis location above the pcb substrate stacks on the moveable table feedback sensor measurement and verification of the location of the moveable table in relation to the drilling unit and plunging the drill bit in the z axis into the stacked pcb substrates in the prior art devices the measurement function metrology is accomplished by position feedback sensors located on the same frame of the device that accomplishes the positioning and drilling this frame has a huge mass base generally a planar granite or cement slab into which the reactionary forces of the positioning and drilling functions is passed its large mass minimizes any reactionary force movement that is experienced by this slab thereby passing very little of these reactionary forces onto the actual positioning measuring and drilling components this has several benefits first it minimizes the settling time of the positioning feedback sensors the time after the positioning of the moveable table is completed until the sensor sees no further movement or backlash and can initiate the signal to begin the drilling second it prevents any additional unwanted movement of the x axis movable table the y axis moveable trolly and the z axis drilling unit which will reduce the accuracy of.