There are many reasons for workpiece overcutting in CNC processing. If the workpiece is overcutted, it will be processed after repair welding, or it will be directly invalidated. In particular, if the workpiece is overcutted during large mold processing, let’s share with you the work experience summarized in CNC processing
Hardware processing
If the workpiece overcut is programmed manually, it is caused by forgetting to take the tool radius into account in the programming. If it is software programming, it may be the selected tool alignment rather than tangency. These two programming methods will lead to the workpiece overcut.
- There is also a fault in tool selection for over cutting of machined parts. For example, a milling cutter with a diameter of 16mm is used in the program, but the result is a milling cutter with a diameter of 20mm. Although the difference between 4mm and 4mm is not big to the naked eye, all the machined parts will become smaller. This requires carefully checking whether the tool diameter is reasonable before machining, and don’t take chances.
- Another reason for workpiece overcutting is that the workpiece coordinate system input is wrong when zeroing. Be sure to remember to offset the radius value of a zero bar. The input error of tool compensation, tool length and tool radius compensation must be input correctly. If the input length of tool length is 0.5mm, the workpiece will be 0.5mm more. For large workpieces, they can’t be used directly. Whether the tool radius compensation is positive or negative should also be considered before tool compensation, Otherwise, it will also lead to over cutting of the workpiece.
The above are the reasons for overcutting of several common machining parts. Others, such as loose spindle and low precision of ball screw, will cause overcutting in the machining process. After overcutting, check the reasons in time to prevent similar situations from happening again.
ken. tang@chengcg.com
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