Designand Key Technology Researchof Large-scale FDM-3D Printing System

Along with the "13th Five-Year" strategic plan,my country's manufacturing industry has gradually entered the golden period of development,and the introduction and introduction of 3D technology has changed the face of my country's traditional manufacturing industry.At present,3D printing technology has been developed for more than 30 years.Both technically and in device development,breakthroughs have been made,and the fields involved are relatively wide,ranging from aviation,automotive,medical and other application fields.To application areas such as manual DIY production and teaching.Fused Deposition Modelling(FDM)technology is an important branch derived from 3D printing technology.Due to its low equipment development cost,wide selection of consumables,and open source control technology,it is used in various industries.But at the same time,due to technical problems,the defects in printing speed and forming accuracy of the equipment have been caused.Therefore,this article mainly focuses on the defects of the current fused deposition 3D printers,such as small forming range,slow printing speed,low forming accuracy Researched,and independently developed FDM-3D printing equipment of super large size,and studied the key issues such as printing speed and forming accuracy.Firstly,related design and analysis of the mechanical system part of FDM-3D printing equipment.By analyzing and comparing the performance of three different types of 3D printers,the Cartesian configuration is selected and designed,and the transmission mechanism of the motion mechanism is selected and theoretically calculated.Then the body frame and nozzle system are designed.The design of the airframe and the forming platform were analyzed statically to verify the rationality of the structural design.Secondly,design the control system part of FDM-3D printing equipment.The hardware mainly adopts the modular design of the main controller,motor drive,temperature measurement and control functions;the software mainly introduces the modification of firmware parameter instructions on the client interface,and the theoretical calculation and setting of the motor's motion accuracy,and finally introduces Cura in detail The meaning of the parameters in the slicing software interface.Then,for the problem of slow printing speed,the factors affecting the printing speed were analyzed,and it was concluded that the extrusion speed of the nozzle system limited the printing speed,and combined with the orthogonal test method,ANSYS /Fluent software was used to simulate the fluid of the nozzle system.In the experiment,the experimental data was analyzed through Minitab for range analysis and varianceanalysis to obtain the degree of influence of the nozzle system parameters on the extrusion speed,and the best optimization scheme was proposed.Finally,a multiple linear regression equation of the nozzle system parameters and the extrusion speed was established.The mathematical prediction model is solved by using the algorithm of least squares estimation.The simulation results are compared with the model calculation results to verify the rationality of the model establishment.Finally,for the problem of poor molding accuracy and quality,the effect of process parameters on it was analyzed.Using the large-scale FDM-3D printing equipment developed,a four-factor three-level orthogonal test plan was designed for sample printing test.Finally,the range of influence of process parameters on forming accuracy was obtained through range analysis and variance analysis,and the best was proposed.Process optimization plan,the final printing test verified the feasibility of the plan and the rationality of the equipment design.