Star Micronics SW-12RII

The Star Micronics SW-12RII is a compact sliding headstock CNC automatic lathe designed for high-speed, high-precision machining of small-diameter components up to 13mm. The SW (compact) designation signals that Star engineered this machine to deliver maximum capability in minimum floor space, making it ideal for shops that need to pack serious Swiss-type production capacity into tight layouts. Despite its compact dimensions, the SW-12RII is a fully featured multi-axis machine with capabilities that rival much larger platforms.

Both the main and sub spindles run at 15,000 RPM with matched 2.2 kW continuous power (3.7 kW peak)—a critical advantage that eliminates the sub-spindle power bottleneck common on many small-diameter Swiss lathes. The matched spindle configuration means back-working operations run at the same speed and power as front operations, enabling aggressive drilling, threading, and contour turning on both ends of the part. This is particularly important for medical and electronics components that often have complex back-end features.

The tooling layout maximizes capability per square foot: 5 front tools and 2 rear tools with 10mm shanks, a 4-spindle sleeve holder with front and rear stations, and an 8-spindle back-working unit accommodating up to 8 stationary and 8 power-driven tools at 12,000 RPM. The power-driven attachments provide 3 front and 3 rear cross-working positions with 1.0 kW continuous motors. C-axis control on both spindles enables milling, polygon machining, and indexed positioning.

Running on the FANUC 31i-B5 control—the same premium platform used on Star's SR-20R IV and SV-20R flagships—the SW-12RII punches well above its size class in programming capability. At 2,100 kg and a remarkably compact 1,995 x 920 mm footprint, it occupies less than half the floor space of a comparable SR-20JII. Rapid traverse at 35 m/min on primary axes, a 139-liter coolant tank, and 4.4 kVA power consumption support efficient production operation.