Abstract: Precision ball bushings running on pecision shafts provide the basic movement and positioning for both the X and Y axes. For smooth precise operation there must be practically nil deflection of the shafts. To accomplish this, cam followers running on guide bars are provided to carry the load; the guide bars being supported along their entire length. The work bed, which can accommodate 4 .times. 8 foot plates, has replaceable nylon pieces screwed on to steel tubing of the frame assembly. Thus, when the drill penetrates the work, it usually encounters the air space, but if it strikes a nylon piece, there is no adverse affect on the operation, and the nylon may eventually be replaced.