Autodesk: Constant cutting forces speed milling

Traditional roughing passes are characterized by taking a series of offset radial passes. With this approach, regardless of the offset step-over value used, the tool will experience increased engagement at every internal corner and when driving into slots. These corners and slots are where cutting forces spike and when the tool is most prone to breakage. A related resource on cutting_forces expands on this point.

To operate at a high feed rate while roughing with traditional strategies, the programmer must instruct the tool to take a shallow axial DOC. This approach overemphasizes cutting with the bottom of the tool rather than using the whole flute length. In this case, the tool stores more heat at the bottom, causing premature wear, instead of spreading heat along the entire flute length.

Adaptive clearing maintains a constant radial tool engagement throughout the cut, eliminating spikes in cutting forces. Image courtesy of Autodesk.

In contrast, maintaining constant cutting forces provides a constant radial tool engagement throughout the entire cut, which eliminates spikes in the cutting forces. This approach allows the programmer to take a larger axial DOC while simultaneously maintaining a high feed rate and extending tool life.

In traditional roughing, the machine operator needs to lower the feed rate to avoid the worst-case scenario: breaking a tool while in a corner or slot, where forces spike. However, this means that for the rest of the roughing operation, the program is not running at optimal material-removal rates.