There are many reasons for overcutting of workpieces in CNC machining. Minor overcutting may require welding and reprocessing, while severe overcutting may render the workpiece unusable. This is especially a headache in the processing of large molds. How to deal with it? Let me share some insights with you. 

If the workpiece is overcut, it is either because the tool radius was not taken into account in manual programming due to carelessness, or because the tool center was selected instead of the tool tangency in software programming. Both of these programming methods can lead to overcutting of the workpiece. 

2. Another reason for overcutting of the workpiece is the wrong selection of the cutting tool. For instance, if the program requires a 16mm diameter milling cutter, but a 20mm one is used instead, although the 4mm difference may seem insignificant to the naked eye, the overall size of the machined workpiece will be smaller. Therefore, it is necessary to carefully check the diameter of the cutting tool before processing and not to take any chances. 

3.Another reason for overcutting of the processed part is that the workpiece coordinate system is input incorrectly when setting the zero position. It is essential to remember to offset by the radius value of the zero position bar. Incorrect input of tool compensation can also cause overcutting. Both the tool length and tool radius compensation must be input accurately. If the tool length is input 0.5mm longer, the workpiece will be milled 0.5mm deeper. For large workpieces, this can render them unusable. Before performing tool radius compensation, it is necessary to consider whether it is positive or negative. Otherwise, directly cutting the tool may also lead to overcutting of the workpiece. 

The above are several common reasons for overcutting in CNC machined parts. Other factors, such as loose spindle and low precision of ball screws, can also cause overcutting during the machining process. Once overcutting occurs, the cause should be checked promptly to prevent similar situations from happening again. 

Chenju Precision specializes in precision parts processing services, offering 3-axis, 4-axis, and 5-axis CNC machining, turning and milling compound processing, CNC lathe processing, and small-batch parts processing, etc. It excels in complex structural parts and can customize special fixtures and jigs for projects. Each product undergoes at least four full inspection procedures, with a quality pass rate of 99.93%. It provides high-quality small-batch processing customization services for customers, with sample production within 3 days and delivery within 7 days. 

If there are any subsequent projects that require CNC machining, you can send the drawings to this email address for evaluation and quotation: info1@us.cjcncmachining.com