A sharpener includes a motor driven shaft with at least one slidably mounted sharpening assembly consisting of a supporting hub structure mounted by its central bore hole on the shaft. The hub structure supports a symmetrically shaped rotating surface containing an ultra fine abrasive material. The rotating surface is pressed with a force of less than 0.2 lb. by a spring action to make sustained rotating abrading contact with a facet of a knife positioned by a knife guide to align the facet into contact with the surface containing the abrasive materials.