A rotary tattoo machine is disclosed. The rotary tattoo machine comprises a machine body having a recess, a cam wheel for insertion into the recess of the machine body, comprising: a first retaining element a cam located on top of, and coaxially with, the first retaining element, the cam coupled with the first retaining element, wherein the cam is configured for coupling with an axle of an electric motor, such that rotation of the axle rotates the cam, and wherein the cam includes a location on its top surface, such that the location is not coaxial with the cam a needle driving shaft coupled with the location on the top surface of the cam, wherein the shaft extends upwards from the cam and a drive element coupled to the shaft, wherein the drive element is further coupled with a needle.
