Views: 7 Author: Site Editor Publish Time: 2021-10-13 Origin: Site
Compared with operators, CNC milling machine (vmc) mold processing requires more experience. The following is a CNC milling machine mold processing experience and precautions during processing that an ALLES CNC found an old operator to share, so that we can do a better job The ideal product.
1. Rough milling. When rough milling, according to the margin given by the machined surface, an end mill should be used to mill the contour surface layer by layer. This kind of rough milling efficiency is high. The curved surface after rough milling is similar to the terraces on the hillside, and the height of the steps depends on the rough milling accuracy.
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2. Semi-finish milling. The purpose of semi-finishing milling is to mill away the steps of the "terraces", so that the processed surface is close to the theoretical curved surface. The use of a ball-end milling cutter generally leaves a machining allowance of about 0.5mm for the finishing process, and the row spacing and step of the semi-finishing process The distance is larger than the finishing.
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3. Finishing. Finally, the theoretical surface is processed. When finishing the curved surface with a ball-end milling cutter, the line cutting method is generally used. For parts with better openness, the turning point of the row cutting should be selected outside the curve table, that is, the curved surface should be extended outwards during programming. For parts with poor openness, due to the change of cutting speed when turning back, it is easy to leave tool marks on the machined surface and blocking surface due to pauses and vibrations. Therefore, during processing and programming, one is to reduce the feed speed when turning back, and the other is to reduce the turning point of the processed curved surface slightly away from the blocking surface during programming. The intersecting line of the curved surface and the blocking surface should be processed separately by a root removal program, so that the processed curved surface and the blocking surface will be smoothly connected without large knife marks.
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4. When the ball end milling cutter is milling the curved surface, the cutting speed at the tip of the ball cutter is very low. If the ball cutter is used to mill a relatively smooth curved surface perpendicular to the machined surface, the surface quality cut by the tip of the ball cutter is relatively poor, so The spindle speed should be increased appropriately, and cutting with the tool tip should be avoided.
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5. Avoid vertical cutting. There are two types of flat-bottomed cylindrical milling cutters, one is that the end face has a center hole, and the end edge is not in the center. The other is that there is no center hole on the end face, and the end blades are connected and pass the center. When milling a curved surface, an end mill with a center hole must not feed vertically downwards like a drill, unless the process hole is drilled in advance. Otherwise, the milling cutter will be broken. If you use an end knife without a center hole, you can feed it vertically downwards, but because the angle of the knife edge is too small, the axial force is large, so it should be avoided as much as possible. A better way is to feed the tool diagonally downward, and then use the side edge to cut laterally after reaching a certain depth.
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When milling the groove surface, the process hole can be pre-drilled for cutting. Although the vertical feed effect of the ball-end milling cutter is better than that of the flat-bottomed end milling cutter, it is best not to use this cutting method because of the excessive axial force that affects the cutting effect.
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6. In the milling of curved parts, if the parts are found to have poor heat treatment, cracks, uneven organization, etc., the processing should be stopped in time to avoid wasting man-hours.
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7. When milling a relatively complex surface of a mold cavity, a longer cycle is generally required. Therefore, the CNC milling machine, fixtures, and tools should be properly inspected before each start of milling, so as to avoid failures in the middle and affect the machining accuracy. Even cause waste.
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8. When milling the mold cavity, the repairing allowance should be properly controlled according to the roughness of the machined surface. For parts that are more difficult to mill, if the machined surface roughness is poor, you should leave more trimming allowance; for flat, right-angle grooves and other easy-to-machine parts, the machined surface roughness value should be reduced as much as possible to reduce the filing work To avoid affecting the accuracy of the cavity surface due to large-area repairing.
CNC milling machines are usually divided into processed products and processed molds, so we also have the name of mold CNC milling machine, or mold machine, product machine, these are just a name, in fact, every CNC milling machine can be used to make products, but There are still some differences when making molds.
