a rotary trimming apparatus includes a base for receiving a material , a rail mounted on the base , a cartridge assembly having a plurality of trimming blades for trimming the material , a carriage slidably mounted on the rail , a selector comprising a plurality of engagement slots , and a set of pins for locking into the engagement slots of the selector knob in order to fix the positions of the selector knob and the plurality of trimming blades . the cartridge assembly plurality of trimming blades are rotatably connected to the selector , and the selector is capable of actuating the plurality of trimming blades by rotating on a plane perpendicular to the base .