1. General principles of the knife path:
Coarse opening: Under the maximum load of the machine tool, in most cases the largest possible knife should be used, the largest possible feed amount, and the fastest possible feed. In the case of the same knife, the advance is inversely proportional to the quantity of food. Under normal circumstances, the load of the machine tool is not a problem. The principle of tool selection is mainly that the two-dimensional angle and three-dimensional arc of the product are too small. After selecting the tool, determine the length of the tool. The principle is that the tool length should be greater than the processing depth. For large parts, you need to determine if the chuck will interfere with the part.
Light knife: The purpose of the light knife is to meet the processing requirements of the surface finish of the workpiece and leave a suitable margin. Likewise, for light knives, use the largest knife possible and advance as quickly as possible, because fine cutting requires a longer time, so use the most suitable feed and feed. Under the same feed, the larger the transverse feed, the faster it is. The amount of advance of the curved surface is related to the smoothness after processing. The feed size is related to the shape of the curved surface without damage. the surface, leave a minimum margin. Use the largest knife, fastest speed and appropriate feed.
2. Tightening method:
1. All clamps are long horizontally and short vertically.
2. Vice clamping: The clamping height should not be less than 10mm When processing the workpiece, the clamping height and processing height should be specified. The processing height should be about 5mm higher than the vise plane to ensure firmness without damaging the vise. This type of clamping is general clamping, and the clamping height is also related to the size of the workpiece. The larger the part, the higher the clamping height will be.
3. Plywood clamping: the plywood is fixed on the workbench with clamps, and the workpiece is locked to the plywood with screws. This type of clamping is suitable for workpieces with insufficient clamping height and large processing force. medium and large rooms.
4. Clamping with code iron: When the workpiece is large, the clamping height is not high enough and it is not allowed to lock the wire at the bottom, use the code iron clamp. This type of tightening requires secondary tightening. First, the four corners are coded and the other parts are then processed. When tightening the second time, do not let the part loosen, tighten first then loosen. You can also encode two faces first and process the other two faces.
5. Tool clamping: for diameters greater than 10 mm, the clamping length should not be less than 30 mm; for tools with a diameter of less than 10 mm, the clamping length should not be less than 20 mm. The clamping of the tool must be firm to avoid collision with the tool and its direct insertion into the workpiece.
3. Classification of cutting tools and their scope of application:
1. According to the material:
White steel knife: easy to carry, used for roughening copper and small steel materials.
Tungsten steel knife: used for cleaning corners (especially steel materials) and light knife.
Alloy knife: similar to tungsten steel knife.
Purple knife; used for high speed cutting and not easy to wear.
2. According to the cutting head:
Flat Knife: Used for flat surfaces and straight sides to clean flat corners.
Ball Knife: Used for medium gloss and smooth knives on various curved surfaces.
Bullnose knife (single-sided, double-sided and five-sided): used for roughing steel materials (R0.8, R0.3, R0.5, R0.4).
Coarse leather knife: used for rough cutting, be sure to leave the remaining amount (0.3).
3. Depending on the tool holder:
Straight Bar Knives: Straight bar knives are suitable for various occasions.
Slanted shank knife: But it is not suitable for straight surfaces and surfaces having a slope less than the slope of the shank.
4. Depending on the blade:
Two blades, three blades, four blades, the more blades, the better the effect, but the more work is done, the speed and feed will be adjusted accordingly, the more blades, the longer the duration life is long.
5. The difference between ball knife and flying knife:
Ball Cutter: When the concave ruler is smaller than the ball ruler and the flat ruler is smaller than the R ball, the light cannot reach it (the lower corner cannot be cleared).
Flying Knife: The advantage is that it can clear the bottom corner. Comparison of the same parameters: V=R*ω, the rotation speed is much faster (flying knife), the strong light flux is bright, the flying knife is mainly used for contour shapes, sometimes the flying knife does not require medium light. The disadvantage is that the size of the concave surface and the plane ruler are smaller than the diameter of the flying knife, and the time is not available.
4. Copper copper processing
1. Under what circumstances should copper male electrodes (electrodes) be manufactured:
If the knife can’t go down at all, it must be transformed into Tong Gong. If there is still a Tong Gong that cannot descend, the form protrudes and must be divided again.
The knife may fall, but if it is easy to break, it should also be made of copper. This should be determined based on the actual situation.
Products requiring spark patterns must be made of copper.
Copper joints cannot be made because the position of the bone is too thin and too high, and the joints are easily damaged and easily deformed. Inserts are required at this stage due to warping and spark warping during processing.
The surface of objects processed by Tonggong (especially the curved surface will be smooth and uniform) can overcome many problems of precision work and drawing.
When a precise shape is required or a large margin is required, raw copper must be made.
2. Tong Gong’s approach:
Select the surface to be made of copper casting, compose the surface to be repaired or extend the surface to be extended, ensuring that all edges of the copper casting are larger than the edges to be punched without damaging the surfaces. other products and remove unnecessary parts that cannot be cleaned. The plane angle (the intersection with the plane angle is the deepest glue position), completes the regular shape. Find the maximum shape of the copper bell, use a boundary then project it onto the support surface; determine the size of the reference frame, cut the supporting surface, and the copper male drawing is essentially complete; prepare materials: length * width; *height, length and width ≥ Ymax and Xmax are the length and width of the actual copper material of the reference frame, which should be larger than the reference frame in the image. Height ≥ theoretical copper pin size + reference frame height + clamping height.
5. The problem of determining the number of drawings
1. When there is no ready-made processing surface, the plane should be divided into four sides, with the center facing the origin and the top facing zero. If the top surface is uneven (for copper grinder), leave a margin of 0.1. , that is, when the number of collisions is reached, the actual value is 0 (z), the figure is 0.1 lower.
2. When there is a ready-made processing surface, create the ready-made surface in image 0 (z). If the plan can be divided into centers, it will be divided into centers. the processing surface should be checked according to the number of ready-made edge collisions (single side), the length is different from the drawing, program according to the actual material. Generally speaking, it is first processed to the size of the drawing, and then the shape of the drawing is processed.
3. When multiple positions need to be processed, the first position (standard position) should be the reference for other positions, including length, width and height. All marks for the next treatment should be those that were processed last time. . Surface shall prevail.
4. Positioning the insert: place it inside the whole body, raise the bottom to a certain height, then raise the design to this height. Divide the plane in the middle according to the whole body and lock it with level screws. height according to the drawing; if it is square, it can be straight. Center ; Basically, use the maximum shape to center a fixture, center it based on the fixture, determine the relative position of the insert drawing and the fixture, then place the drawing origin at the center of the fixture.
6. Choice of tool path for roughing:
1. Curved surface grooving
The key is the choice of scope and appearance.
The processing area of the toolpath is as follows: the selected surface in the selected range is the terminal surface, and the principle is that the tool can reach all places from the highest point to the lowest point. It is best to select the entire surface, and the boundary can only be the area to be treated. The non-surface area extends less than half the tool radius. Because there is enough margin for other surfaces, it is automatically protected. It is best to extend the lowest line, as there is an R gong at the lowest point.
Knife selection: If the tool cannot advance spirally or diagonally, or the area that cannot be processed is sealed and left for secondary roughing.
Before using the light knife, you must roughen all non-rough areas, especially small corners, including two-dimensional corners, three-dimensional corners and sealed areas, otherwise the knife will break. Secondary roughing: generally, the three-dimensional groove is used to select the range, and a flat bottom knife is used. Those that can use the plane groove and profiled tool paths are used. Without damaging other surfaces, move from the center of the tool to the selected boundary. Generally, the limit is not refined. Use a quick two-way angle according to the situation, angle 1.5 degrees, height 1. the shape is strip, it cannot. For spiral cutting, use a diagonal feed. Generally, the filter is open, especially when the curved surface is rough. The power plane should not be low to avoid collision with the knife, and the safety height should not be reached. below.
Retraction: Generally relative retraction is not necessary, absolute retraction is used. When there is no island, relative shrinkage is used.
2. Plane grooving: milling various flat surfaces and concave flat grooves. When milling certain open surfaces, the limit must be determined in principle, the tool can be advanced (larger than a tool diameter). tool diameter and periphery.
3. Shape: When the selected plane is suitable for shape overlay, use shape overlay to lift the knife (plane shape). When the knife lifting point and the knife lowering point are at the same point, there is no need to lift the knife. Knife. Generally lift the knife on a plane and try not to use relative heights; The direction of correction is usually the correct correction (avoid the knife).
4. The toolpath adjustment for mechanical correction: the correction number is 21, change the computer correction to mechanical correction, the feed is vertical, and the place where the knife cannot pass is changed to a large R without leaving any margin.
5. Contour shape: suitable for closed surfaces. For open surfaces, if there are four circles, the neck surface must be sealed. Whether it is in four circles or not, the range and height should be selected (arc shaped). the feed must be roughened), used for roughing situations: the machining distance in any plane is less than a tool radius. If it is greater than a tool radius, a larger tool or two contours of the same height must be used.
6. The curved surface streamlines: it has the best uniformity and sharpness and is suitable for light knives to replace the contour shape in many cases.
7. Radial knife path: suitable for situations where there are large holes in the middle (use less often). Things to note: When you operate the knife, the knife is not sharp, the knife is too long, and the workpiece is too deep. When the piece is too deep, it should be walked through and not up and down. The sides of the sharp corners of the workpiece must be divided into two tool paths and cannot be crossed. The edge is better when using a bare knife. Extend (advance and retract the knife in an arc).
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