Prerequisites for thread repair
1: Fix the concentricity again,
2: Understand the turning method of threading instructions
Let me first explain the meaning of the G76 command, the place to pay attention to the thread repair and the way of cutting.
The format of G76 is as follows:
G76 P(1) Q(2) R(3)
G76 X(4) Z(5) P(6) Q (7) R(8) F(9)
1: It is composed of six digits. For example, 020060 represents the precision turning (02) twice, (00) the retracting length, the general system parameter setting, (60) represents the angle of our tooth knife.
2: Infeed value per time, such as Q200, the one-sided infeed is 0.2, but some systems are only one-sided 0.1 according to the system, and some systems directly write 0.2 instead of two hundred. Such as the new generation system
3: Fine car margin, also how much fine car reserved
4: X-axis end point coordinates
5: Z end point coordinates
6: Tooth height, here is a calculation involved, metric tooth height=0.5413*tooth pitch, imperial tooth=0.6495*tooth pitch
7: Turning amount of the first cut.
8: Taper
9: Tooth distance
Let me explain to you the G76 turning path
G76 turning is to take the knife from right to left. The knife will slowly move to the middle position along the right edge of the tooth. So G76 requires the angle of the tooth knife as shown in the figure:
Red takes the knife path for us. You can see that the knife goes from the right to the left.
Everyone understands the G76 turning path, and understands the instructions, so now I will tell you how to rework threads. S300
G76 P020060 Q100 R0.03
G76 X19.0 Z-20.0 P1083 Q300 F2.0
We first clamp and clamp the workpiece to ensure the concentricity of the workpiece, write the turning instruction, and pay attention to the speed not to be too fast. We repair the thread mainly by eyes, and it will be inaccurate if it is too fast. Pay attention to modify the second G76 The P value of the above program is P1083 is the standard tooth height, add Xiaobian WeChat Yuki7557 to get the 10G CNC tutorial, then we change it to p1583. What we should pay attention to is that the Q value of the first turning amount is Q300 in the above program, then we change it If the data is greater than the value of P+Q, then we will not turn to the workpiece in the first turning.
After finishing the work, we can start to repair the thread, the most important step is the thread. We have to pay attention to the thread. Before the thread is correct, our program can only take one thread.
When the program is turning the first thread of the thread, we use the naked eye to see the position of the tool tip, it must be the position of the tool tip, and see which side of the thread the tool tip deviates from. The tool tip position cannot be on the left or in the middle. We use the tool to compensate to the right. The tip of the tool seems to be to the right of the thread. After the tool is repaired, look at the machine to see if the thread is biased to the right. The correct position 2, 3 is the wrong position. Be careful not to make single-direction compensation. . .
