How to Realize Tool Compensation Function in CNC Machining

In CNC machining center, because of tool wear, regrinding or replacement of new tools, the parameters of relevant tools in the programming process will change, and the tool trajectory will change. If the adjustment is not enough, the final machining accuracy of the workpiece will be affected. For example, the tool center trajectory is calculated from scratch and the program is revised. In this way, not only time-consuming and labor-consuming, but also high error rate, the most convenient way to call CNC CNC system tool radius compensation performance, workpiece programming we only need to compile processing procedures according to the appearance of the workpiece, the system will automatically calculate the tool center trajectory, so that the tool deviates from the appearance of the workpiece a radius value. Even if there is a change in tool parameters, only the detailed tool parameters need to be changed, and no change in all the processing procedures is required. This greatly improves the processing efficiency of the machining center.

1. Establishment and cancellation of cutter radius compensation

Simply speaking, tool radius compensation can be divided into two kinds: left compensation and right compensation. Goodbye is defined by G41 and G42. When the center path of the tool is located on the right side of the part appearance, it is called the right compensation of the tool radius; otherwise, it is called the left compensation of the tool radius.

1. Establishment of Tool Radius Compensation

The establishment of tool radius compensation is a process in which the tool center trajectory transits from coincidence with programming trajectory to deviation from a tool radius value when the tool approaches the workpiece from the starting point to the feed speed. G41 is used to compensate the left radius of the cutter and G42 is used to compensate the right radius of the cutter.

2. Revocation of Tool Radius Compensation

The process of revoking cutter radius compensation is similar to that of creating cutter radius compensation. After the final cutter radius compensation track is processed, the cutter withdraws the workpiece and returns to the point of withdrawal. In this process, the cutter radius compensation should be revoked, and its instructions are defined by G40. The tool withdrawal point should be located outside the appearance of the part, and it may be the same as the starting point, but it may also be different.

2. Matters needing attention in inputting compensation for cutter radius in CNC machining

The change of tool radius compensation usually occurs after a period of processing in the machining center. For a continuous program segment, when the cutter radius compensation is changed, the vector at the end of a program segment is calculated with the cutter compensation specified by the program segment.

When programming NC program, we usually input the compensation amount of tool radius into the compensation code as positive value. If the compensation amount of tool radius is set as negative value, when the target of tool trajectory is fixed, it is equal to the compensation position instruction in NC program. The exchange of G41 and G42 may occur in processing. Since the processing of the outer side of the workpiece by the heart turns into the inner side processing, unexpected problems arise, so it is necessary to pay attention to the configuration of two compensation targets when inputting radius compensation.