A feed mechanism for feeding a filament through a print head assembly in an FDM printer. The feed mechanism includes a first oval-shaped track having a plurality track elements extending around the first track and a second oval-shaped track having a plurality of track elements extending around the second track, where the first and second tracks counter-rotate. A space is defined between the first and second tracks that receives the filament in a manner so that the track elements that are in the space contact the filament, where rotation of the first and second tracks in opposite directions causes the filament to be driven through the space and onto the print head.