CNC rapid prototyping technology
L) Product 3D model construction. Since the RP system is driven directly by the 3D CAD model, it is necessary to construct the 3D CAD model of the workpiece. The 3D CAD model can be built directly using computer-aided design software (eg Pro / E, I-DEAS, SolidWorks, UG, etc.), or a two-dimensional pattern of an existing product can be converted to form a three-dimensional model or a product entity Laser scanning, CT tomography, CNC rapid prototyping get point cloud data, and then use the reverse engineering method to construct the three-dimensional model.
2) Approximation of three-dimensional model. As the product often has some irregular free surface, before processing to approximate the model to facilitate the subsequent data processing work. As STL format file format is simple, practical, has now become the field of rapid prototyping CNC standard interface file. CNC rapid prototyping It is a series of small triangular plane to approximate the original model, each small triangle with three vertex coordinates and a normal vector to describe the size of the triangle can be selected according to the accuracy requirements. STL file has two kinds of binary code and ASCll code output form, the binary code output form of space than the ASCII code output form of space occupied by much smaller, but the ASCII code output can be read and checked. Typical CAD software comes with the ability to convert and output stl format files.
3) slicing of the three-dimensional model. According to the characteristics of the model to be processed to select the appropriate processing direction, CNC rapid prototyping in the forming height direction with a series of spaced-apart plane to cut the approximate model, in order to extract the cross-section of the contour information. Interval generally take 0.05mm ~ 0.5mm, commonly used 0.1mm. The smaller the interval, the higher the molding accuracy, but the longer the molding time, the lower the efficiency, otherwise the accuracy is low, but the efficiency is high.
4) forming processing. According to the cross-sectional profile of the slicing, under the control of the computer, the corresponding forming head (laser head or nozzle) is scanned according to the profile information of each section, CNC rapid prototyping and the material is deposited on the work floor layer by layer, and then the layers are bonded , Eventually get the prototype product.
5) Post-processing of molded parts. The molded parts are taken out from the molding system, polished, polished, painted, or placed in a high temperature furnace for post-sintering, to further improve its strength.