Slow Tool Servos technology is an option which can be added to the Nanoform ultra-precision lathes for the production of freeform (3D) surface. STS differs from FTS (Fast Tool Servos) in that the machine moves the spindle axis in synchronization with spindle rotation at lower RPMs to produce non-rotationally symmetrical designs.

So it performs as a positioning C-axis programmed for the workholding spindle which enables the diamond turning of surface structures such as torics, off-axis spheres and progressive designs.

The STS technology therefore enables the machining of large sagitta workpieces without incorporating additional equipment (such as Fast Tool Servo attachments) and fixturing to the standard two-axis Nanoform machining system.

STS technology tends to lend itself larger diameter parts, whereas FTS devices are more appropriate for typical smaller ophthalmic diameters.


  • 10mm amplitudes at 2 Hz
  • Larger excursions available at lower frequencies
  • 70 Hz bandwidth available for smaller excursion