An all-electric web feeding, cutting and sheet dispensing machine includes a bi-directional cutting knife on a reversible carriage driven by a reversible-rotation knife-drive shaft. The carriage includes a ball-bearing-wheeled linear actuator riding on the knife-drive shaft propelling the carriage along this shaft in cutting strokes in one or the other direction as this shaft is rotated in one or the other sense of rotation for cutting sheets off from a web of resilient packaging material. A combined knife-guard and clamp jaw (guard/clamp) holds the web and protects the moving knife from contact with foreign objects while the knife is traveling during each cutting stroke. At the end of each cutting stroke a cam on the knife carriage lifts the guard/clamp in readiness for feeding another length of web. The machine may be set for various operating modes: (1) automatic supply on demand by feeding and cutting of measured lengths of web triggered by an operator's removal of each previously cut sheet; (2) semi-automatic for feed and cut in response to manual actuation of a switch; (3) timed operation feeding and cutting of sheets at pre-set intervals of time; (4) selectable feeding and cutting of either of two different widths and/or two different types and/or two different thicknesses of web material coming from upper or lower feed rolls. The knife includes two sharp replaceable blades removably mounted tip-to-tip in the knife carriage with their cutting edges inclined downwardly in opposite directions from those adjacent tips.