The "Smart Shaft" refers to a shaft used for centrally supporting a roll wound of paper, film, foil, textiles or similar materials and combinations or laminations thereof and used for unwinding, rewinding, inspecting or storing the material; The shaft may have built in abilities to sense the weight of the wound material or lateral (not axial) forces acting on the shaft, control the axial position of the roll of material as measured from either or both ends of the shaft, grip the central core of the roll of material, control braking torque and resulting unwind strip tension, control winding torque and resulting winding tension or any combinations of the sensing, positioning and control functions previously mentioned; Power sources and sensing may be external to the shaft; Power sources may be pneumatic, hydraulic, mechanical, electrical or any combination thereof;The shaft may be of any length, diameter, material and may be supported at either one end (cantilevered) or both ends