Design And Research Of 3D Printer For Orthosis Rapid Prototyping

Since the 21 century,especially in the last decade,3D printing technology has been rapidly developed and widely used.Due to its perfect technology and low cost,the fused deposition 3D printing technology has gradually entered the public view.With the development of economy and society,the demand for products is diversified and individualized,the demand for a customized product is becoming more and more.Especially in the design of rehabilitation medical devices,such as,various orthotic devices need to be designed and manufactured according to the actual situation of each person.Under this background,this paper applies 3D printing technology to the digital design and manufacture of orthosis,which can reduce the production cost,improve the quality and provide individualized design for individuals.However,the low cost desktop level 3D printer has limited molding space and low precision,so it can not meet the needs of industrial manufacturing.According to the requirement of industrial manufacture,this paper designs a 3D printer that can meet the needs of spinal orthosis.In order to meet the demand of high precision and large size for industrial manufacture,after studying the forming principle and concentrated common mechanical structure of FDM melt deposition 3D printer,a gantry polar coordinate molding structure is proposed.The 3D modeling and detailed design of each drive shaft of 3D printer are carried out.The Ansys simulation of the beam with larger span is carried out to verify the structural stiffness.In this paper,the dynamics simulation of Adams is carried out,and the fuselage modality is calculated and analyzed,and the rationality of the structural design is verified.The system firmware Marlin of 3D printer is studied deeply,the principle of speed planning is analyzed,and the coordinate conversion module is written for Marlin firmware.The coordinates under the scale system are converted to the coordinates of the polar coordinate system.The forming time of double nozzle and single nozzle is simulated by Matlab software.In the aspect of closed-loop control,the magnetic encoder is chosen to control the nozzle in a semi-closed loop,which solves the problem of stepping motor out-of-step,and a physical prototype is made for the closed-loop control system,which verifies the effectiveness of the closed-loop control system.