Carbon Fiber Composite 3D Printer System Development

Carbon fibre-reinforced polymer(CFRP)has the advantages of high specific strength,high specific modulus,low density,high temperature resistance,corrosion resistance,etc.and they are widely used in national military fields such as aerospace and industrial manufacturing.3D printing technology has advantages including easy molding of complex parts,fast molding speed,and high material utilization.3D printing technology with CFRP can quicky and accurately manufacture CFRP molded parts,which has important engineering application value.Aiming at the characteristics of the molding process about long-fiber carbon fiber composites,a carbon fiber composite 3D printer system based on fused deposition modeling(FDM)technology was constructed in this paper,including hardware and software subsystems.The main contents of this paper are as follows:Firstly,the principle and process of 3D printing of CFRP were studied,and key technical points in the forming process were explained.On this basis,the mechanical structure of CFRP 3D printer was designed and analyzed,and the hardware structure of the CFRP 3D printer was constructed.Secondly,aiming at the problem of huge redundant vertices in the STL model file,this paper realized the rapid removal of redundant vertices in the STL model file by designing a hash function.The comparison experiment showed that the hash function designed in this paper produces less address conflicts,improved the search performance of the hash table,and performed topology reconstruction on the STL model with redundant vertices removed.The principle of STL model hierarchical slicing was studied,and STL mode rapid hierarchical slicing was realized based on the established topology relationship of the STL model.Thirdly,in view of dual nozzle switch problem,the relationship between the dual nozzles working coordinate systems was studied,and switch of the dual nozzle working coordinate system was realized by generating the G code of the dual nozzle working coordinate system conversion.Aiming at the problem that traditional 3D printing slicing software cannot support single-layer material definition,the single-layer material definition was introduced and the G code generation method of material switching between layers was studied,and the two-material layered printing algorithm combining long-fiber carbon fiber and PLA was realized.In view of the long-fiber carbon fiber path continuity characteristics,the long-fiber carbon fiber layer adopted a zigzag filling method,and the position of the jumping point and the cutting point on the long-fiber carbon fiber layer was matched to realize the long-fiber carbon fiber 3D printing.Finally,this article developed 3D printing slicing software based on VS2015 and Qt,including STL model loading,STL model topology reconstruction,dual nozzle switching,dual-material layered printing,position matching,G code generation and other functional modules.The secondary development of the lower computer control system was carried out,and the function of the shearing mechanism control module was added to solve the problem of cutting the long fiber carbon fiber at the cutting point.The STL model file was loaded into the 3D printing slicing software,the G code file was generated after layered slicing,and the printing experiment was verified in the 3D printer designed in this paper.