Study On Printing Path And Model Decomposition Problem For FDM 3D Printer

3D printing is a new technology that flourishes in the manufacturing industry and is a manufacturing technology with meaning of industrial revolution.3D printing known as incremental manufacturing.It can print products that are highly complex and lightweight and stable.The core idea of 3D printing is layer-by-layer printing which the entire three-dimensional model is created by continuous accumulation between layers.With the popularity of 3D printing technology,people's demand for printing efficiency and molding quality has become higher and higher.On the one hand,the nozzle's movement path planning can effectively improve the printing efficiency;on the other hand,some support structures need to be printed to support the structure in the printing process.It will not only cause waste on the material,but also reduce the printing efficiency.It is necessary to manually remove these extra support structures.So the nozzle's movement path planning and the decomposition of the pre-printing model are the key issues in 3D printing.In this paper,the nozzle's path planning and the model decomposition before printing are studied,including the voxelization of the model in the path planning problem,the convex decomposition and the pyramid decomposition in the model decomposition problem.The main research results of this paper are:(1)The key issue is to use four neighborhoods knowledge to transform the nozzle's path planning problem into traveling salesman problem in the problem of moving path planning of the nozzle.Considering the disadvantages of the existing three-dimensional printing path planning methods are complicated programming and slow search speed,this paper proposes an optimal moving path planning method for nozzles in 3D printing based on improved backtracking algorithm.This method firstly voxels the 3D model and then the weights between the voxel points of each layer are divided according to the relevant knowledge of the four neighborhoods,the path planning problem of the nozzle is transformed into the traveling salesman problem and then used the improved backtracking algorithm to obtains the optimal movement path planning of the nozzle.Experiments show that the algorithm of this paper runs fast and can give a high quality approximate solution when the parameters are set properly.(2)3D model decomposition based on Delaunay triangulation came up with in the model decomposition problem.Firstly,the 3D model is Delaunay triangulation and the set of tetrahedrons is used to approximate the 3D model;then according to the top-down layering method recursively segments the calculated tetrahedron,which is applied continuously to the generated sub-portions until the concavity threshold is reached.In order to ensure non-overlapping convex hulls,the objects are segmented according to a series of clipping planes based on concavity,balance and symmetry;then the convex hulls are continuously merged under the maximum concavity standard;finally,the obtained convex hulls are through resampling to minimize their complexity(ie,the number of their triangles)which ensure the accuracy of the approximation,the resulting 3D model can be composed of several convex blocks,each convex block is printed separately,and then pasted.The support structure is not required in the printing process,which saves printing materials and improves printing efficiency.