Machining strategies for difficult materials

Dr. Scott Smith, University of North Carolina at Charlotte, shares his views on the strategies that need to be adopted by machine shops to mill difficult materials. Toolpath strategies for efficient milling need to consider much more than part geometry, including those cuts to be selected that will not cause chatter, stall the spindle, break the teeth or tool shank or separate the tool from the spindle. A good toolpath strategy also needs to impart specified surface finishes and achieve acceptable metal-removal rates and tool life. Milling cuts provide an opportunity to change the process of milling these materials, as they are interrupted. Some NC programming packages have tools, such as trochoidal motion, which help the programmer control the radial DOC.