DESIGN AND DEVELOPMENT OF A ROTATING NOZZLE FOR LARGE-SCALE CONSTRUCTION 3D PRINTER

Abstract

This capstone project focuses on the design and control system of a rotating nozzle for 3D construction printers. The existing 3D construction printer at Nazarbayev University is equipped only with a stationary nozzle with a circular cross-section which does not allow the use of a non-circular nozzle due to the lack of a rotational mechanical system in the printer itself. This, in turn, limits the opportunity to effectively enhance mechanical properties such as tensile and compressive strengths. The proposed design is developed through computer aided design (CAD) software and the printer's configuration is adjusted for integration of the rotational mechanism’s control system. This design includes a full description of rotational mechanism and integration steps to the 3D printer. Besides the main motor of the 3D printer, an additional motor is installed next to the nozzle and controlled by a new axis (parameter) which is added into G-code. New axis, called “U”, will be responsible for rotation of the nozzle itself. For the development of this axis design, the cosine law is applied. The calculation is based on the three consecutive points in G-code to obtain an accurate degree of rotation for the nozzle. Based on testing results one trowel printhead had the highest flexural strength of 5 MPa and a trapezoidal printhead with teeth had the highest compressive strength of 8 MPa compared to circular default nozzle head with 6 MPa and 2 MPa for compressive and flexural strengths respectively. The new optimized nozzle design is implemented in existing 3D printers, which allows it not only to develop its capability in the printing process but also to make sustainable contributions in 3D construction industries.