Every new part brings its own set of challenges to the machinist. Not the least of these is the metal to be cut, milled or drilled. Extremely hard metals like H-13, S-7, M-2, or CPM, and exotic metals like Titanium, Inconel® or Incoloy® can be particularly difficult.
The chief problem manufacturers run into when dealing with these kinds of materials, is failing to look at the whole picture. Our tendency is to “make do” with what we have and rely on a new fixture or different cutting tool to solve the problem. As a result we may be able to produce the part, but not as efficiently as we would like. And as we all know, efficient operation means greater productivity, less scrap and rework and a stronger bottom line.
According to Brian Stall, one of Gosiger’s 3-D Application Engineers, looking at the complete picture means thinking about the tooling, fixtures, machine spindle rigidity and speed, and the machine’s control system.
“It’s really about the complete package. The tooling is critical, including having the right geometry, hardness, coating and sharpness. On many hard metals, for example, if the tool is too sharp it will wear prematurely. It’s also important to maintain the proper cutting environment. In some cases, using coolant will shock the tool and cause it to break down quickly, and since chips absorb most of the heat produced, they should be quickly removed from the cutting area.
Of course, the heart of the process is the machine, itself. That’s why it’s important to have equipment with a rigid spindle and tool holder to eliminate the vibrations that cause out-of-tolerance parts. Maintaining a constant cutting feed rate is also vitally important. If the spindle starts to slow down, you’ll burn up the tool. In the same way, the machine’s control must be capable of maintaining consistent acceleration and deceleration, and to quickly process data.”