Abstract: A gantry-style apparatus for positioning a working member with respect to plurality of "X" and "Y" coordinate positions is described which includes a pair of parallel spaced apart "X" support members defining a plurality of "X" coordinate positions and a "Y" support member defining a plurality of "Y" coordinate positions. The "Y" support member extends transversely across the "X" support members and has a first end, a second end and a mid-point between the first end and a second end. A center-pull "X" drive system is provided for moving the "Y" support member axially along the "X" support members. A working member mounting is movably secured to the "Y" support member. A "Y" drive system is provided for moving the working member mounting axially along the "Y" support member.