Bridging the CAM-to-machine gap

When people ask why it’s important to select a high-quality post-processor, I always liken it to building a house. The builder creates the foundation and frame but often relies on other suppliers for the finishing work—everything from flooring to painting to siding. The resulting work often varies in quality, with multiple contracts and several warranties. Unfortunately, there is no one-stop shop for building a home.

The process is often similar for owners of machine tools, who must rely on a third party for post-processor development. Typically, end users are forced to purchase machine tools and CAM and post-processing software from different suppliers, leading to discrepancies in quality, thoroughness and delivery. Furthermore, the CAM-generated program may not run successfully on the machine tool, creating a bottleneck.

Post-processors for machine tools are analogous to drivers for computer printers, where a different driver is required for printers from various manufacturers and for each computer operating system. This is called many-to-many mapping, meaning a printer must have a driver for every operating system and every operating system must support every printer. Similarly, a post-processor translates CAM-dependent solid models and cutter toolpaths into the G and M code that a machine tool understands.

Every CNC machine tool is unique because of its controller and axis configurations, and each CAM program is different because of its proprietary toolpath generation and internal data storage format. The post-processor is a module that bridges the gap between the software and machine.

Courtesy of DMG / Mori Seiki USA

Work flow of the Manufacturing Suite post-processor from DMG / Mori Seiki.