Machining center, CNC milling machine tool compensation

In CNC system of machining center and CNC milling machine, tool compensation function includes tool radius compensation, Angle compensation and length compensation.

(1) Tool radius compensation (G41, G42, G40) The radius value of the tool is pre-stored in the memory HXX, XX is the memory number. After the tool radius compensation is performed, the CNC system automatically calculates and makes the tool automatically compensate according to the calculated results. Tool radius left compensation (G41) refers to the left side of the tool deviation direction of the programming machining track (as shown in Figure 1), tool radius right compensation (G42) refers to the right side of the tool deviation direction of the programming machining track. Cancel tool radius compensation with G40, cancel tool radius compensation can also use H00.

Note in use: to establish and cancel the tool time, that is, the program segment using G41, G42, G40 instructions must use G00 or G01 instructions, shall not use G02 or G03, when the tool radius compensation is negative, the function of G41 and G42 is exchanged.

There are two compensation forms of tool radius compensation: B function and C function. As B function tool radius compensation is only calculated according to this program, it cannot solve the transition problem between program segments and requires the workpiece contour to be processed into rounded corner transition, so the workpiece sharp corner is not good in process. C function tool radius compensation can automatically process the transfer of the tool center trajectory between the two program segments, and can be completely programmed according to the workpiece contour. Therefore, almost all modern CNC machine tools use C-function tool radius compensation. At this time, the following two program segments that require the establishment of the tool radius compensation program segment must have displacement instructions specifying the compensation plane (G00, G01, G02, G03, etc.), otherwise the correct tool compensation can not be established.