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CNC machining skills, you will make a fortune after reading it!

    1. The speed of the white steel knife should not be too fast.
    2. Copper workers should use less white steel knives and more flying knives or alloy knives.
    3. When the workpiece is too high, it should be cut in layers with knives of different lengths.
    4. After roughing with a large knife, use a small knife to remove the remaining material to ensure that the remaining amount is consistent before smoothing the knife.
    5. Flat-bottomed cutters are used for flat surfaces, and less ball cutters are used to reduce processing time.

    6. When the copper worker cleans the corner, first check the size of the R on the corner, and then determine the size of the ball knife to use.
    7. The four corners of the calibration plane should be flat.
    8. Where the inclination is an integer, use the inclination tool for processing, such as pipe position.
    9. Before doing each process, think clearly about the margin left after the previous process is processed, so as to avoid empty tools or excessive machining.
    10. Try to take simple tool paths, such as shape, grooving, one-sided, and less surrounding contours.
    11. When taking WCUT, if you can take FINISH, don’t take ROUGH.
    12. When the shape of the knife is polished, first rough, then finish, when the workpiece is too high, first smooth the edge, and then smooth the bottom.
    13. Reasonably set tolerances to balance machining accuracy and computer calculation time. For rough cutting, the tolerance is set to 1/5 of the allowance, and for smooth cutting, the tolerance is set to 0.01.
    14. Do a little more work and reduce the time of empty tool. Do a little more thinking and reduce the chance of mistakes. Do a little more auxiliary line auxiliary surface to improve the processing condition.
    15. Build a sense of responsibility, check every parameter carefully and avoid rework.
    16. Diligent in learning, good at thinking and continuous improvement. When milling non-planar surfaces, use more ball cutters and less end cutters. Don’t be afraid to pick up the cutter; clean the corners of small knives and finish with big knives; don’t be afraid of surface repair.(CUSTOM ALUMINUM EXTRUDED ENCLOSURE)

    17. High hardness of blank material:

    Climb milling is better Low hardness of blank material: Climb milling is better The machine tool has good precision, rigidity and finishing: it is more suitable for down milling, otherwise it is more suitable for up milling. Climb milling is strongly recommended for finishing the inner corner of the part. Roughing: up-cut milling is better, finishing: climb milling is better Tool material has good toughness and low hardness: more suitable for roughing (large cutting amount machining) Tool material has poor toughness and high hardness: more suitable for finishing (small cutting amount machining) ).

    18. Copper male processing methods and matters needing attention:

    Before writing the tool path, after the three-dimensional drawing is completed, the center of the drawing should be moved to the origin of the coordinates, and the highest point should be moved to Z=0, and the machining can be performed. The copper male spark position can be processed with a negative reserve. Before processing, it is also necessary to check whether the clamping direction of the workpiece is the same as the direction of the graphics in the computer, whether the positioning in the mold is correct, whether the clamping fixture hinders processing, and whether the directions of the front and rear molds match. Also check whether the tools you use are complete, the benchmarks in the calibration table, etc. Matters needing attention when processing copper males: For the determination of the spark position, generally the reserved amount for young males (that is, fine males) is 0.05~0.15, and for rough males 0.2~0.5. The size of the specific spark position can be determined by the model master. Are there any dead ends that cannot be processed by the copper master, and whether it is necessary to dismantle an additional sangong. The tool path for processing copper workers is generally as follows: large knife (flat knife) roughing – small knife (flat knife) clearing angle smooth knife with ball knife and smooth surface. Generally, teachers use a flat knife instead of a ball knife, and then use a small knife to roughen the large knife, then smooth the shape to the number, then use a large ball knife to smooth the surface, and then use a small ball knife to smooth the surface. However, using a small knife to process the dead corners that the big knife cannot pass through can limit the range of the small knife, so as not to broadcast too many empty knives. Copper males, especially young males, have relatively high precision requirements. The tolerance is generally 0.005~0.02, and the step distance is 0.05~0.3. When the copper opening is thick, the over-knife position of the ball knife should be reserved, that is, the outer shape of the copper opening should be made thicker and deeper by one knife radius. Tong Gong also needs to process the median, calibrate the table benchmark, and calibrate the copper worker during spark discharge. Generally, the copper worker processed from the three sides (upper, lower, left, and right) must have three datum planes. Copper material is relatively easy to process. The cutting speed and rotation speed can be faster. When roughing, leave a machining allowance of 0.2~0.5, depending on the size of the workpiece, the machining allowance is large, and the cutting can be fast when roughing ,Improve efficiency. Note: The parameters in parentheses are when the high-speed steel knife is roughing the steel. The above cutting speed refers to the roughing, and the smooth shape F=300~500, and the steel smoothing knife F is 50~200.

    19. The problem of rough opening of the front mold:

    First, rotate the copper male drawing 180o in the front view or side view to become the front mold drawing, of course, add the pillow position, PL surface; where the original body needs to be left in the front mold, do not use the mirror body method to remove the copper The engineering drawing becomes the front mold drawing, which is sometimes wrong (when the X and Y directions of the copper male drawing are not symmetrical). There are two difficulties in the processing of the front mold: the material is relatively hard; the front mold cannot be easily welded, and it cannot be wrong. The principle of using a knife when the front mold is rough is similar to that of the copper worker. The large knife is rough → the small knife is rough → the large knife is smooth → the small knife is light, but the front mold should be used as much as possible. Do not use a knife that is too small, it is easy to bounce the knife. Use the knife handle () to make rough cuts, and try to use a round nose knife when the knife is smooth. Because this knife is large enough, powerful, and has a parting surface, there is usually a problem when the parting surface is touched when the knife is smooth. The number of holes should be accurate for threading, and the machining allowance of 0.2~0.5 should be reserved for the cavity (set aside for sparks). This is to correct the surface of the mold cavity by 0.2~0.5 in the positive direction, and set the machining allowance to 0 when writing the tool path. When roughing or smoothing the front die, it is usually necessary to limit the cutting range. Remember that the range you set is the range of the tool center, not the range of the tool boundary, not the range processed by the tool, but a larger tool radius. The commonly used tool path method for roughing the front die is surface grooving and parallel smooth knife. When the front mold is processed, the parting surface and the pillow surface are generally processed to the right number, and the penetrating surface can be left with a margin of 0.1 to prepare for the mold.

    20. Problems often encountered by the mold after processing:

    There are two kinds of back molds: original body or inlay. The back mold is made of steel like the front mold, and the material is relatively hard. It should be processed with a knife handle as much as possible. The common tool path is the surface groove shape, and the parallel milling knife. The principle of knife selection is Large knife roughing → small knife roughening → large knife light knife → small knife light knife. The rear mold drawing is usually made of copper male drawing reduced material level plus PL surface, pillow position, and what is left in the original body. If the material level is relatively uniform, you can directly leave a negative material level in the processing information volume, but PL (Parting surface), pillow position, and the touch-through surface cannot shrink the material position. At this time, you can first correct these faces by a material level or draw the section. A problem often encountered in the original body is that the ball knife cannot clear the sharp corner. At this time, the flat knife can be used to take the steep slope of the curved surface to process the clear angle. For example, the back mold is divided into the hidden frame and the core. When cutting, pay attention to the empty knife several times, otherwise the frame will have a slope, the upper side is accurate, and the lower side is small, it is difficult to match the mold, especially for the deep frame, we must pay attention to this problem, and the knife for the light frame should also be new. OK, and use a larger knife. If the core is too high, you can turn it over to process the frame position, and then assemble it into the frame, and then process the shape. Sometimes there are branches. Be careful not to overcut the shape with a ball knife. Be sure to protect the steps of the branch. In order to facilitate the matching mode, the frame size can be smaller than the outer size of Kexin -0.02/s The tolerance and step distance of Kexin light knife can be slightly larger, the tolerance is 0.01~0.03 and the feed is 0.2~0.5.

    21. Problems in the processing of loose copper males:

    Sometimes it is difficult to process the whole copper male, there are dead corners that cannot be processed, or it is not easy to process, and the required tool is too long or too small, you can consider an extra copper male, and sometimes you need to clear the corner copper male, this kind of copper The processing of the male is not difficult, but it is necessary to find out the offset number when the spark is really good, and the calibration benchmark.

    22. Processing of thin disk copper male:

    This kind of copper male is easy to open during processing. A new knife should be used during processing. The knife should be smaller and the feed should not be too large. During processing, the length a can be adjusted first, but a large allowance for d (such as 1.0 mm) and then go on two sides, each time the depth is h=0.2~1, the depth of the knife should not be too much, and do not go around the knife, but should be divided into two sides.(AUDIO SPIKE)

    23. The direction of left and right pieces and one out two:

    Sometimes a set of molds will produce two parts. For the left and right parts, the graphics can be made by mirroring. If there are two identical parts, the graphics must be equalized or rotated in XY, and must not be mirrored. Be careful not to make the opposite direction.

    24. Orientation of the mold:

    The four guide bolt holes of the mold base are not completely symmetrical, and one is asymmetrical. Therefore, when processing the front and rear molds, it is finally clear that there are benchmarks on each template. The processed front and rear molds must be combined with the benchmark. , especially for the mold formed by the original mold base must be paid attention to. When drawing, also pay attention to the direction. The direction of the copper male is the same as that of the front view (top view). The direction of the core and the frame of the Tibetan branch is the same as that of the copper male, and the front mold is opposite. Some decorative lines such as grooves or bosses on the curved surface are not easy to process because they are relatively narrow. For the groove, we generally avoid the groove, that is, mill it deeper, and then make a sinking surface with a sag. Generally, the boss can only be separated into a sag, and the large copper stub is not used, so as to ensure the quality.

    25. Mould, product fit tolerance:

    A set of products usually has several or more than a dozen parts. The main matching dimensions of these parts are guaranteed by computer gong processing. It is very important to choose a reasonable tolerance, especially some product design drawings do not consider the matching problem. The matching of the bottom and the surface shell is undoubtedly a 0-to-0 fit, and the positioning is guaranteed by the branch. The tolerance of the concave branch and the convex branch is generally 0.1MM, unilateral. The accessories on the big body, such as transparent mirrors, are generally 0.1~0.2 unilaterally smaller than the size of the big body. For movable accessories on the big body, such as buttons, the shape of the accessories is 0.1~0.5 smaller than that on the big body. The surface shape of the accessories on the big body is generally the same as the surface shape of the big body, and it can come down from the surface of the big body.

    26. Draft angle (draft angle):

    The mold must have a mold slope, otherwise it will be scratched. If the drawing does not indicate it, you can discuss with the mold master. The draft angle is generally 0.5~3 degrees. If the mold is etched, the draft angle should be larger. , 2~5 degrees, depending on the thickness of the etching pattern.

    27. Knife problem:

    In many cases, when the knife is just milled, the amount of the knife is relatively large, which is easy to cause the knife to break and the knife to bounce. At this time, you can first open the lower knife position or lift the knife away, or cut the knife outside the material, in short. Take this issue into full consideration. Grab the knife, bounce the knife, drop the knife When the processing volume is relatively large, the knife holder is too long, and the knife is too small. This often happens. The processing volume is relatively large, especially when the concentration of the feed is large, it is easy to occur, such as the light side depth H=50mm diameter 3/4 knife, we can divide it into 25mm secondary processing, it is not easy to happen. The tool clamp is too long. The length of the tool is very important for processing. The clamping should be as short as possible. It is easy for beginners to ignore this problem. The program paper must indicate the length of the tool. It is easy to grab the knife when turning the corner. The solution is to first use a smaller knife to clear the corner in layers, and then change the larger knife to the side. Like the semicircular groove with diameter 8 as shown in the figure, if it is processed directly with the R4 knife, it is easy to grab the knife at the lower knife position. The solution is (1) use R3 to scan the tool path (2) first use R3 to roughen, and finally Use the R4 knife to clear the corner light knife.

    28. Sharpen the knife:

    Computer gongs have different shapes and often need to grind various small knives. Various forming knives are worn out and need to be sharpened. Only when the following proportions are reached can a usable knife be ground 1. The four corners of the tool should be the same height 2. Point A is higher than point D 3. The front (blade face) of the tool is higher than the back, that is, there is a certain clearance angle.

    29. Gouge check:

    Gouge is a problem that often occurs in masterCAM, so be careful. Over-cutting may occur in multi-surface roughing, light knife, tool path trimming, shape, and grooving, even if the parameters of the chest and the three-dimensional image are correct, it may also occur. Some of them are errors of the software itself. Simulate the tool path again and check it repeatedly in the top view and side view. The tool path without inspection is not allowed to be used on the machine. During profile milling, if the position of the lower tool is not properly selected, it will also overcut. You can change the lower tool position to avoid it.

    30. Milling direction:

    Computer gongs are generally down milling, unlike up-cut milling by milling machines. The reason is that the rigidity of computer gongs is better, it is not easy to let the knife, the backlash is small, and the milling shape or inner groove are left compensation. When machining left and right symmetrical shapes, the shape tool path cannot be mirrored, otherwise the processing effect of the mirrored side will not be good. Writing of the program paper In order to communicate with the personnel who operate the machine tool, the program paper should include 1) program name 2 tool size and length 3 machining tool path method 4 machining allowance 5 roughing or smooth tool 6 drawing file name 18. Graphic management computer drawing should be For proper file management, it is best to create a catalog for each product, and a different name for each part, such as A10 for the copper public drawing, A10C for the rear mold drawing, A10CAV for the front mold drawing, and A10S1 for the loose copper drawing. , which makes it clearer. 19. Format conversion between different software: For communication with AutoCAD, MastCAM version 7 and above can directly read DWG files, and versions lower than 7 can first convert to DXF format in autocad. Other CAM software such as (cimtron, pro/e, UG) can be converted into IGS format first.

    31.DNC usage:

    After the program is completed, after checking, it can be copied to the DNC computer for actual processing without any problems. Then start the DNC software, find the program to be run, and press ENTER.

    32. Coordinate system:

    There are three types, mechanical coordinate system, machining coordinate system, and temporary coordinate system. In the mechanical coordinate system, the mechanical zero point is a reference point on the machine. After each power-on, the origin is determined after returning to zero. The position of the mechanical zero point is determined by the machine factory and should not be changed. The machining coordinate system is used for workpiece processing and is a sub-coordinate system of the mechanical coordinate system. Take a point in the mechanical coordinate system (usually the center point of the workpiece) as the coordinate origin, and record the mechanical coordinate value of this point as the machining point. The origin of the coordinate series can be set as the machining coordinate system. Temporary coordinate system: use each point as the coordinate origin at any time. Corresponding to the coordinate value, there are also three kinds of coordinate values: mechanical coordinate value, processing coordinate value, temporary coordinate value (also called relative coordinate value) 22. Common filter value: Common filter value 0.001~0.02, filter radius R=0.1~0.5. Take a large value for the roughing toolpath, take a small value for a smooth surface toolpath, take a large value for a small surface radius, and take a small value for a large surface radius. Filtering can effectively reduce the program capacity and make the tool move more smoothly, but if it is too large, it will affect the machining accuracy.

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