Can opener includes a shell, power mechanism, transmission mechanism, and cutting mechanism. The transmission mechanism includes a main drive gear, eccentric disc, and movable block. The main drive gear and eccentric disc are coaxially arranged, and the surface of the main drive gear facing the eccentric disc is provided with a linkage groove. The movable block is arranged on the eccentric disc in a liftable manner to insert into or withdraw from the linkage groove. One side of the movable block is provided with a first inclined surface and a first vertical surface, and the other side is provided with a second vertical surface. When the main drive gear rotates forward, the linkage groove abuts against the first vertical surface to drive the eccentric disc to rotate forward. When it rotates forward beyond the limiting position, the linkage groove slides relative to the first inclined surface to stop driving the eccentric disc to rotate forward. When it rotates backward, the linkage groove abuts against the second vertical surface to drive the eccentric disc to rotate backward.

Improved systems and methods for cutting a can are provided. The system includes a can cutting device having a main body, a can support assembly, and a cutter. The can support assembly has a can support rotatable about a can support longitudinal axis. The can is positionable in a mounted position that holds the can body in contact with the can support at least at a cutting location. When the can is positioned in the mounted position, the can is rotatable about a can axis of rotation. When the cutting surface is in contact with the can body supported by the can support at the cutting location and the can is rotated about the can axis of rotation, the cutting surface cuts the portion of the can body at the cutting location.