Such was the case for Sturges DesignWorks, a company in Portland, Ore., that provides automation and design engineering solutions in a variety of industries, including medical products, electronics, fixturing and tooling, and research and development. The company was working with a client who needed a special machine built that required substantial CNC lathe work. But Sturges didn’t have a lathe. “CNC lathes are expensive, take up much needed floor space, and have a steep learning curve,” explains Dan Sturges, company CEO. He considered a CNC mini lathe, but found that it would not be precise, rigid or accurate enough for the work required.

To address the issue, the company developed what it calls the Sturges Turning Head system to bridge the gap between traditional, full-featured CNC lathes and low-productivity, small CNC mini lathes. “I had always wondered why we couldn’t somehow do precision CNC lathe work on a CNC milling machine,” Mr. Sturges says. “The problem is, even if you attach a lathe tool to the mill spindle and lock it, there’s still a tiny bit of play that makes it impossible to maintain a standard of precision. So we developed a turning bar toolholder that places the tip of the tool at the spindle’s center of rotation, eliminating the slight play in the tool tip and providing the precision and accuracy needed for professional, high-quality swis type automatic lathe work on a mill.” Based on this principle, the company built the prototype for the Turning Head system, which is capable of external turning, facing and contouring operations. An optional cross slide accessory bolts onto the table, allowing for plunge operations such as parting and grooving.