4R Foot/Flange

The model 4R Foot/Flange integrates a 1hp AC induction motor with a model 4R BLOCK-HEAD® air-bearing spindle in a convenient-to-install package. Featuring a flange for face mounting and a dovetail for foot mounting, the spindle is best suited for such continuous duties as grinding, flycutting, and turning, especially to optical finishes. The spindle is shown with a piloting faceplate. This popular option permits interchanging chucks, collets, and wheel mounts with .000,050” concentricity to the spindle’s axis. Tool presetting and wheel conditioning are made more accurate, and spindle down-time during tool change is minimized, since no manual centering is required.


  • Model 4R BLOCK-HEAD® air bearing spindle
  • Mounting system that allows for both foot and flange mounts
  • Faceplate details per customer specifications
  • Integral 1 horsepower AC induction motor
  • Variable frequency AC motor drive with braking


Maximum speed: 7,500 rpm

Working load capacity: 50 lb radial
200 lb axial
200 lb-in tilt

Spindle weight: 70 lb


  • Grinder wheelheads, especially for diamond wheels
  • Flycutter spindle for ultra-flat mirrors
  • Ultra-precise lathe headstocks
  • Ultra-precise workheads for inside and outside diameter grinding

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