A netizen talked to me about his experience of hitting a knife in his CNC career and the reason for it. I was in a terrible mood at that time. I just started to enter the pit of the machining industry a few years ago and bumped into it twice.
1. When I was just working, I opened a Japanese slow-moving wire. There is no computer CAM programming. The FANUC programming machine used is the kind of yellow box. PTP paper take away program, cut a figure 8 circular die. Simulation (all normal when drawing the trajectory) I got stuck when I put on the paper tape, 8 holes were punched, the holes were waste, and the sentence was missing. As a result, I walked to this place and cut across. Fortunately, it is wire cutting, and the bed is okay.
2. Later, a single-arm gantry milling machine was opened in Heilingen, Germany. This bed has a special function of superimposing the strokes of Z (spindle head) and W axis (single arm beam). Z stroke 550. W stroke 1550. If I use Z-800 in the program, Z and W actually move together. Is it Z to 550, W to 250, Z to 250, W to 550, or something else. This requires a special post-processor to process the cls tool path file generated by the original proE. This post-processor (a program written by a German, with a piece of button like a fighter jet, the operation is very cumbersome to stand up.) It is very easy to make a mistake in the operation.
Then...it was wrong as expected. Milling a pit of the casting internals mounting table, just go through the program, huh? The spindle sleeve did not go away, and the beam went down with a swish. Click! Fortunately, the partner reacted quickly with a slap and an emergency stop, only the lighting tube was broken.
Who said: "The more knives you hit, the better the technique, the better you practice!" This truth, just know it on the front line, and the boss will feel distressed if he knows it. Thinking about it, I am afraid, the more timid I get, the more timid I get. This is easy to say now, every time I hit the knife, I am frightened... alas!
How to prevent the CNC lathe from hitting the tool
1) Frequently check whether the limit stop of the lathe is in the correct position and whether it is loose; (but it should be noted that the limit of the machine tool can only play a protective role at the limit position of the stroke, due to the difference of the tool extension position and the different size of the workpiece blank, etc. The existence of the situation, in most cases, the limit of the machine tool cannot effectively prevent the tool from hitting during the machining process).
2) After the program input is completed, you must carefully check whether there is an error, so as to avoid the collision of the knife due to the wrong coordinate number input.
3) Correctly calibrate the tool and set the tool compensation. Please pay attention to the Z-direction zero point used for tool calibration should be consistent with the Z-direction zero point used in programming when trial cutting in the Z direction to avoid tool collision due to inconsistent settings of the workpiece coordinate system .
4) At the beginning of operation, set the rapid override to be slower (for example, it can be set to 25%).
5) After the program is compiled, single-segment debugging should be performed first, and the display screen should be switched to a page where the workpiece coordinate system and the program being executed can be viewed at the same time.
6) During the debugging process, always pay attention to the current absolute coordinate value and the coordinate position of the end point of the next block to determine the distance the tool will move, and then observe the distance between the current tool position and the workpiece position to determine whether there is a possible collision. Pay special attention to the following two points:
★Pay special attention to the first G00 movement command in the program (and the first G00 movement command after tool change). Many tool collision accidents occur in this block. Please put your left hand on "Pause" when running this block. ("Feed Hold") button, press "Pause" if necessary.
★If you are unfamiliar, you can set the first G00 coordinate slightly far away from the blank, and then use the second G00 to locate the starting position to find the problem in time during single-segment operation.
★The next block is a tool change command. The extension length of the relevant tool must be considered, and the next block can be run only after making sure that there will be no tool collision when the tool post rotates.
7) If G50 is used to set the coordinates in tool setting of GSK980 series products, you must pay attention to the possibility (depending on the system parameter settings) that the absolute coordinates will be restored to the initial value after returning to the mechanical zero point, which may cause accidents. Hua Medieval Star 18iT uses absolute tool offset, please do not use coordinate system setting commands casually.
8) If the tailstock must be used during machining, the limit position where the electric tool post does not collide with the tailstock in the X direction and the limit position where the carriage does not collide with the tailstock in the Z direction must be considered when installing the tool. (If the tailstock is not used for a considerable period of time, it is recommended to temporarily remove the tailstock to avoid collisions)
