In CNC lathing, compensation functions are used to adjust the machining program to compensate for various factors that can affect the accuracy and quality of the machined part.These functions allow for precise control of the tool’s position, dimensions, and tool paths to account for inherent machine or tooling inaccuracies, workpiece variations, and other variables.
Tool Length Compensation (TLC)
- Tool Length Compensation adjusts the tool position along the Z-axis to account for variations in tool length. It ensures that the tool tip reaches the desired position accurately
- By specifying the tool’s length offset, the control system adjusts the Z-axis position accordingly during machining, compensating for any differences in tool length.
Tool Radius Compensation (TRC)
- Tool Radius Compensation adjusts the tool path based on the tool’s radius to account for the tool’s geometry.
- By specifying the tool’s radius offset, the control system adjusts the tool path to ensure that the machined dimensions are accurate and match the programmed dimensions.
Wear Compensation
- Wear compensation compensates for tool wear during machining. As tools wear down over time, their dimensions can change, affecting the machined part’s accuracy.
- By measuring and monitoring the tool wear, the control system can automatically adjust the tool’s position or dimensions to maintain the desired accuracy.
Cutter Compensation
- Cutter compensation adjusts the tool path based on the tool’s geometry, taking into account the tool’s shape and its effect on the machined part’s dimensions.
- By specifying the cutter compensation value, the control system adjusts the tool path to achieve the desired part dimensions, accounting for the tool’s shape.
Part/Workpiece Offset
Part or workpiece offset allows for the adjustment of the workpiece’s position or dimensions to compensate for any inaccuracies or deviations in its geometry.
By specifying the offset values, the control system adjusts the tool path or tool position to account for the workpiece’s actual dimensions or position.
These compensation functions are essential for achieving the desired accuracy, precision, and dimensional integrity of the machined parts.
They help compensate for various factors that can affect the machining process, ensuring that the final parts meet the required specifications. Proper utilization of compensation functions in CNC lathing leads to improved part quality, reduced scrap rates, and increased productivity.
Types of Cutter Compensation
There are two common types of tool compensation, one is tool position compensation, also called tool offset compensation, and the other is tool nose arc radius compensation. There will always be a certain deviation between the position where the tool is installed during the machining process and the theoretical position.
At this time, tool compensation is required to reduce the deviation. In traditional mechanical machining, once the tool needs to be changed, the machining program of the entire process needs to be changed. The tool compensation method can avoid the disadvantages of requiring large-scale changes in the process, and use tool compensation to solve the deviation problem.
Necessity Of Tool Compensation
Numerical control technology is mainly to control the cutting tool through computer programming, let it move within a certain range, and theoretically guarantee the quality of machining through unified standard setting. But this is only an ideal state. In actual operation, it is impossible to fix the tip of the blade at the same position. This is because there will be errors not only in changing the blade, but also in the radius and size of the arc of different tools.
This will lead to changes in the size and accuracy of the parts, which will affect the machining process. Tool compensation is the fundamental method to improve machining accuracy and quality. CNC machine programming is a digital programming technology based on the reference position and aiming at the automation and standardization of machine tool machining.
A major problem faced by CNC machine tool programming is that when there is an error between the actual position of the machine tool tool and the reference position, it will increase the error of CNC turning-milling machining. At this time, the role of tool compensation will be highlighted. In addition, the tool position change caused by tool wear can also be solved by compensating the tool offset.
The Role Of Tool Compensation
Reduce the machining dimension error caused by tool size and installation position, reduce the deviation between actual operation and drawing definition, and greatly improve the efficiency and quality of the entire machining process. Tool compensation can quickly and accurately adjust the tool size during the machining process , improve the yield rate of processed products, reduce the size of processed products, and make the quality of processed materials more stable. It can be seen that tool compensation is a leading technology and an important force in the development of modern industry.
Improving the adaptability of the tool In the process of CNC lathe machining, the wear and replacement of the tool will cause errors in the processed parts, and tool compensation is an important method to reduce these errors, which has an irreplaceable role in improving the machining accuracy of the CNC lathe . If X and z are assumed to be the tool compensation values of the original CNC machine tool, △X and AZ are the amount of deviation caused by the tool due to wear and other factors after a period of machining, then, (X-LX) and ( Z-AZ)) is the new tool compensation value. It can be seen from the assumption that when changing the tool, there is no need to change the NC control program, just adjust the change amount. If the error is due to tool replacement, the accuracy problem caused by tool wear offset will also change, and the operator needs to replace the data with a new tool compensation value to improve machining accuracy and tool efficiency. The operation of CNC machine tools is simpler and more convenient.
It is not only a daily work in the production process, but also an indispensable measure to improve the cnc machining efficiency. In this process, the actual deviation value between the tool center and the workpiece contour does not play much role, but needs to be manually set by the operator. The so-called rough machining means that the precision of the part is low. During the rough machining process, the compensation value of the tool radius is the sum of the actual radius and the finishing allowance.
In the process of finishing, only one data of tool and actual radius value is needed to operate. In addition, it is also possible to switch between rough and fine machining during operation. The specific operation process is as follows: set the tool for rough machining, and input the tool radius compensation value. This process requires manual operation, including the two data of tool radius compensation and machining allowance. ;Secondly, the transition from rough machining to finishing machining is to input fine-tuning amount on the basis of rough machining. When operating the fine-tuning amount, it should be specified according to the actual machining situation. For example, if the finishing size is smaller than the roughing size, the fine-tuning star is a positive value; otherwise, if the finishing size is larger than the roughing size, it is a negative value. Aiming at the problem of the deviation of CNC machine tools, it can be effectively adjusted through the method of tool deviation compensation. This method not only improves the precision of workpiece machining and machine quality, but also simplifies the process of cnc machining operations and reduces the difficulty of machine tool operation [3].