Abstract: A gluing machine employs substantially linear conveying motion and has easily installed change parts, which adapt the machine to handle thin paper or relatively heavy cardboard. A vacuum head with compound motion delivers a sheet of cardboard or paper from a vertical stack by lifting the leading edge and advancing it substantially horizontally between drive rolls which deliver the sheet under a glue roll. A glue spreader roll is mounted on eccentrics for adjusting its spacing from the glue roll. For relatively stiff sheets, a pair of removable presser rolls under the glue roll continuously flex the moving sheet into close contact with the glue roll and the sheet is delivered onto a dual compartment vacuum conveyor for positive ejection and accurately timed delivery to a downstream processing station. The presser rolls are replaced with a fixed bridge for handling flexible sheets, and the vacuum head is rotated while in motion by an air cylinder carried on the support arms for the vacuum head.