Okuma America Corp. recently announced the availability of Turn-Cut as a programming option for its horizontal machining centers (HMC) to cut bores and diameters with circular or angular features — or both — thus eliminating the need for special-purpose machinery such as lathes, fixtures, components, or special tooling.
The technology isn’t brand new. YouTube videos of machine shops using Turn-Cut have been posted since at least the beginning of 2012, and Okuma has reportedly been working on this feature for a decade.
Nevertheless, Turn-Cut is useful for many types of parts, especially valves, pipes, and manifolds, in high-growth industries such as oil and gas, automotive, and aerospace, along with mold and die, water treatment, heavy equipment, and plumbing components.
It uses Okuma-developed mechatronics and standard tooling to create inner- or outer-diameter (ID/OD) surfaces on stationary workpieces, including large and unbalanced parts.
The key to Turn-Cut is that the operation, activated by a G-code in the machining system’s program, synchronizes the circular motion of the X and Y feed axes with the spindle’s turning angle to maintain position control of the tool tip, keeping it on the programmed cutting path and perpendicular to the workpiece face.
According to details released by Okuma, the program is commanded in much the same way as a CNC lathe with a Z-X turning program. “The cross-section configuration is commanded with Z-X” and “the X-axis is commanded with the radius of X-Y in a continuous circular motion.” These movements are what enables the machine tool to horizontally cut cylindrical workpieces and achieve ID/OD turning, facing, grooving and taper operations, machining of different diameters with one tool, machining of tapered holes, and machining IDs/ODs that exceed the largest tool diameter available, the company adds.
Okuma says the addition of the Turn-Cut function does not affect HMC machine performance and does, it claims, enable more consistent machining operations whether or not it is activated. Since it uses standard fixturing and tools, and additional work can now be done on the HMC, setup times are, moreover, reduced.
(Sandvik Coromant worked with Okuma on Turn-Cut’s research and development and realized the cutting tools for many applications.)
Okuma applies its own CNC and motion-control systems to Turn-Cut. These are usually designed to match the parameters of its HMC models. The company also provides a control technology called Thermal Active Stability, which monitors temperature fluctuations in key areas and makes adjustments to minimize “thermal growth” and maintain machining accuracy.
To run the Turn-Cut, several additions are necessary. These include an Abso-scale, for high-precision (0.05 micron) machining accuracy, an all-axis ball-screw cooling system, and Super-NURBS (Non-Uniform Rational B-Spline), a high-speed CNC function that Okuma says achieves machining accuracy and product quality in half the time of conventional technology. Super-NURBS is said to be desirable for complex shapes or where major diameter changes occur in short linear distances.
Here is an Okuma video of Turn-Cut, posted on YouTube.
Videos of the system that have been posted by other companies are accessible by doing a Google search for “Okuma Turn-Cut System.”