1. Analyze dimensioning methods in part drawings Figure 1 unified benchmarking method The method of marking the dimensions on the same basis or directly marking the coordinates is a unified method of labeling. This marking method (shown in Fig. 1) is most suitable for the machining characteristics of CNC machine tools, which is convenient for programming, but also maintains the design basis and process standards. The consistency of the measurement datum and the workpiece origin setting. Designers often consider the factors of assembly and use characteristics when dimensioning, and often use locally-distributed labeling methods (shown in Figure 2). This labeling method brings a lot of inconvenience to process planning and numerical control programming. The decentralized labeling method was changed to the unified standard labeling method. Because of the high precision of NC machining and the high precision of repeat positioning, the unified reference labeling method will not produce a large cumulative error. Figure 2 Decentralized benchmarking method The condition of the geometric elements that make up the part contour is an important basis for numerical control programming. For manual programming, calculate the coordinates of each node that constitutes the contour of the part. When programming automatically, define all the geometric elements that make up the contour of the part. If a certain condition is not sufficient, you cannot calculate the nodal coordinates of the part contour and the geometry of the part contour. Elements, which make it impossible to program, therefore the drawings should completely express the geometric elements that make up the part's outline. The radius of the transition fillet reflects the diameter of the tool. The ratio of the tool diameter to the depth of the contour of the machined workpiece is related to the stiffness of the tool, as shown in Fig. 3a, when R < 0.2H (H is the depth of the contour of the workpiece to be machined. ), then determine the part of the workpiece processing technology is poor; as shown in Figure 3b, when R> 0.2H, the tool's equivalent stiffness is better, the workpiece's processing quality can be guaranteed. Figure 3 Internal groove transition radius As shown in Figure 4, when milling the bottom plane of the workpiece, the greater the fillet radius r of the bottom of the groove, the poorer the ability of the milling cutter end edge to mill the plane, and the maximum diameter of the milling cutter in contact with the milling plane d=D-2r (D For cutter diameter), when D is constant, the larger r is, the smaller the milling plane area of ​​the milling cutter end face is, and the ability to machine the surface is accordingly reduced. Figure 4 Corner radius of the groove Stereo Light Curing Molding - Sla STEREO LIGHT CURING MOLDING - SLA Sla,Sla 3D Printing Service,Sla Printing Service,Sla Rapid Prototyping Ningbo Rongna Technology Co.,Ltd , https://www.prototyping-machining.com
It mainly uses photosensitive resin as a raw material, and utilizes the characteristic that liquid photosensitive resin will cure quickly under ultraviolet laser beam irradiation. The photosensitive resin is generally liquid, and it immediately initiates a polymerization reaction and completes curing when irradiated with a certain wavelength of ultraviolet light (250 nm to 400 nm). SLA focuses on the surface of the light-curing material by focusing ultraviolet light of a specific wavelength and intensity to solidify it sequentially from point to line and from line to surface, thereby completing the drawing of a layered cross-section.
The processing technology of CNC machine tools involves a wide range of factors, and there are many influencing factors. When analyzing the processing technology of workpieces, the processing characteristics of CNC machine tools should be considered.