Design And Research For Hybrid Executive Mechanism Of The FDM 3D Printer

The executive mechanism is the key moving part of the FDM 3D Printer and one of the key factors affecting print quality.However,at present,FDM 3D printer generally use a decoupling mechanism with three translational DOF or parallel mechanism based on the Delta configuration as the executive mechanism.Which leads to problem such as a single print posture,which seriously affect the surface precision and mechanical properties of the printed product.Therefore,it is necessary to develop a new type of 3D printer executive mechanism to improve the above problems.In order to achieve different directions printing postures of FDM 3D printers,this paper designs a 5-DOF FDM 3D printer hybrid executive mechanism.Analysis of the executive mechanism in kinematics,kinematic performance,dimensional synthesis and Virtual Prototype Simulation.The main work is as follows:First of all,the configuration design of the FDM 3D printer hybrid executive mechanism is carried out.According to the expectation DOF of the parallel mechanism,The 2UPU-SPR parallel mechanism module ware selected and assembled by the limb kinematic chain which synthesized vis the constraint screw theory.A series mechanism with two rotational degrees of freedom is connected on the moving platform of the 2UPU-SPR parallel mechanism,A 5-DOF FDM 3D printer hybrid executive mechanism is obtained.Secondly,kinematic analysis was performed on the FDM 3D printer hybrid executive mechanism.The forward and inverse position solutions analysis of the parallel mechanism module,2-DOF printing nozzle and executive mechanism are performed.Establishes the the complete jacobian matrix which using screw theory and velocity analysis of the 2UPU-SPR parallel mechanism module.Then,the kinematic performance analysis and dimensional synthesis of the 2UPU-SPR parallel mechanism are performed.Based on the inverse solution mathematical model,get work space boundary using polar coordinates search method,the impact of structural parameters on workspace and global conditioning index ware analyzed.Taking the workspace and global conditioning index as the optimization goal,the dimensional synthesis is carried out,and the optimal structural size parameters are obtained.The results showed that each of them increase by 10.1%and 13.3%.Finally,a virtual prototype model for FDM 3D printer hybrid executive mechanism is established.The kinematics simulation of the 2UPU-SPR parallel mechanism is carried out,and the correctness of the velocity theory analysis is verified.Simulation analysis of 3D print trajectory on an inclined plane.It provides the basis for the design of the subsequent control system.The FDM 3D printer hybrid executive mechanism design in this paper can not only achieve the flexibility and diversification of the print gesture,but also has good operability,which It provides a theoretical reference for the design and engineering application of the 3D printer executive mechanism.