“I tell the machine tool salesmen that I’d love to buy a new machine from them, but only if they can bring me the résumés of three qualified machinists,” says Bob Bergstrom, president of St. Vrain Manufacturing in Longmont. St. Vrain Manufacturing is a precision machine shop serving high tech, aerospace, telecom, and other industries.
With CNC, CMM, CAD/CAM and other new technologies, modern machining has transitioned from an art to a digital-based science. The one major knowledge gap that has not been digitized is the selection of speeds, feeds and depths of cut which have been described as:
“...often ad-hoc and empirical. Process parameters, such as machining speeds, feed rates, and tool selection, are typically chosen by costly, trial-and-error prototyping, with the resulting solutions often sub-optimal.”
“In CNC machining, usually the programmer programs speeds and feed rates that are as maximally tuned as calculations and general guidelines (with charts and formulas) can supply. The operator then fine-tunes the values while running the machine, based on sights, sounds, smells, temperatures, tolerance holding, and tool tip lifespan.”