How to compensate the tool radius for CNC milling
How to compensate the tool radius for CNC milling
With the development of numerical control machine tool processing technology, programmers program according to the contour size on the drawings over the years. If the cutter center moves along the processed contour of the part, then the dimension of the part cannot reach the ideal size after the processing, which will lead to inconsistent programming contour and actual contour. This paper introduces how to compensate the radius of nc milling cutter.
In the general industry, the solution to this problem is to set up the tool radius compensation. Programmers only need to program according to the dimensions on the part drawings to ensure that they can produce the ideal dimensions required by the machining drawings.
Tips for application of tool radius compensation function:
1. Processing of round holes
For the general round hole, a off - milling cutter can be used on the CNC milling machine.
(1) selection of cutter: for such round holes, if the workpiece material is tempered with 45 steel, you can choose a carbide end mill.
(2) due to the good mechanical performance of CNC milling machine, it is generally preferred to use down milling. You can use the "eat less and walk faster" method to save most of the auxiliary work time.
(3) programming path determination. Note that the tangential cut and cut method of arc transition must be adopted. The radius of the excessive arc must be larger than the radius of the cutter and smaller than the radius of the hole.
(4) arrangement and program processing of rough finishing. Finish machining only needs to call a subprogram once, once lower the blade to the bottom of the hole, reduce the amount of feed by 5 times, set the complementary value as the theoretical value, other unchanged, finishing can be completed.
2. Processing of inner and outer walls
To mill out a closed groove on a plane, the groove width has precision requirements. CNC milling machine can also be completed with an end milling cutter. Through graphics and process analysis, the processing idea should also be "eat less and walk faster". Now the key problem is that the graph element is more complex, and the calculation of each node is difficult. We need to mark according to the dimensions, calculate the coordinate values of each point on the inner and outer walls, determine the cutting point, and set up a program according to the trajectory. The characteristic of machining inner and outer wall with this method is that only one program is needed to finish the rough machining of inner and outer wall by constantly modifying the value of cutter compensation.
The tool radius compensation function is very important in nc milling. Programmers only need to program the contours of the parts being processed. The field machining operator only needs to modify the value of the cutter filling address through the operation panel to accurately control the machining process and machining precision of the part. Therefore, for technical personnel of nc machining, it is necessary to keep learning and accumulate experience to master the method of tool radius compensation.