Abstract: An imaging subsystem for forming an image on a sheet comprises a tray for holding a supply of sheets, a ramp for directing a sheet from the tray to the imaging subsystem and a drive assembly including a roller for moving a top sheet of the supply of sheets in the tray to the ramp with a reciprocating roller stroke. The drive assembly is configured to maintain a constant roller stroke distance between the roller and the ramp. A sheet feeder comprises a linkage and a roller disposed on the linkage for contacting and driving a sheet from a supply of sheet material by a reciprocal linear movement through a roller stroke distance. The linkage is configured to maintain a constant roller stroke distance between the roller and the ramp. In a method, a roller is moved in a reciprocating stroke to drive a sheet from a supply of sheets to a ramp that directs the sheet to an imaging subsystem. A constant distance is maintained for each stroke as the supply of sheets diminishes.