This work deals with the designing and developing a Graphical User Interface (GUI), called Atlas_GcodeSender, for control of a 3D printer based on a 5R parallel robot. First, a conceptual design stage is performed through an application activities modeling (AAM) by using the nomenclature of IDEF0. The programming each functional module of the GUI in JAVA language is also detailed. Atlas_ GcodeSender allows three control modes: manual, semiautomatic/MDI (Manual Data Input) and automatic, and it has been implemented on a 3D printing process using a 5R parallel robot with open technology controller.