Trochoidal milling stands for highly dynamic milling at excellent material removal rates. Unfortunately, the tool paths involved are optimal only for grooves. At EMO 2019, HEIDENHAIN changed this state of affairs with a new option for the TNC 640, TNC 620, and TNC 320 controls. Optimized Contour Milling (OCM) allows the trochoidal milling principle to be utilized for a considerably wider range of applications. In addition to the roughing of any open or closed pocket and island, OCM also offers cycles for the finishing of pocket floors and side walls.
As is the case with trochoidal milling, OCM limits the wrap angle and permits milling along the entire cutting edge. With OCM, the user can program any contour on the TNC 640 as usual from the shop floor. The control then automatically calculates the optimum tool paths for holding the cutting parameters constant. The subsequent machining operation runs with continuously optimum cutting values, resulting in increased machining speed and a noticeable reduction in tool wear.
A sample part presented at EMO showed just how effective the new milling strategy is. For our sample workpiece at the tradeshow, OCM lowered the machining time and tool wear by a factor of three compared with conventional milling strategies.