The model 4R Twin-Mount spindle combines a high-power brushless-DC motor (liquid cooled) with a model 4R BLOCK-HEAD® air bearing spindle for the most demanding applications. This is the spindle to use in a rapid-cycle, start/stop operation, or when the ultimate in speed stability is required.

Model 4R BLOCK-HEAD® air bearing spindle
Cast-iron housing for horizontal axis or vertical axis operation
Custom faceplate per customer specifications*
Dynamically-balanced spindle rotor
Brushless-DC motor mounted directly to the spindle
Resolver motor commutation for smooth rotation
Motor controller with wide speed range
Available with integral 1 hp AC induction motor
All required connectors and cables

Speed Ranges: 0-2,000 rpm
0-5,000 rpm
0-10,000 rpm
Torque: Up to 60 lb-in continuous

Speed Regulation: As low as 0.0001%

Motor performance can be tailored to your application. Motors with narrower speed ranges will have better low-speed torque and speed regulation. Load capacity, stiffness, and accuracy of the 4R BLOCK-HEAD® air bearing spindle are unaffected by the motorization process.

Motor style
Encoders of various levels of precision
Vacuum work holding
Water cooling for motor
Piloted faceplate for ultra-accurate interchangeable chucks, collets, or wheel mounts
Ultra-precise workheads for I.D. and O.D. grinding
Ultra-precise lathe headstocks
Spin table for Moore G-18 jig grinder
Spin table for roto grinding on a surface
Flycutter spindle for ultra-flat mirrors
Grinder wheelheads, especially for diamond wheels
Roundness testers