Ultra-Precision Aerostatic Tool Spindle with HSK-A63 tool interface


With a spindle error (Error-Motion) of under 15 nm, the highest stiffness and load capacity for an aerostatic tool spindle, our ASD-PH63M adds HSK-A63 tooling to Ultra-Precision spindle quality.

The ultra-low spindle error and the iron-less motor technology make this spindle model ideal for grinding glass lenses with reduced sub-surface damages, which reduces the time required for polishing. Moreover, its HSK-A63 tool interface allows a quick and repeatable wheel change.

A spindle soak time of under 9 minutes (cold and standstill to 10 krpm), and a thermal shaft growth of less than 0.8 micron are achieved by the strictly symmetrical design combined with our efficient thin-film liquid cooling technology.

The cartridge design with axial spindle connectors allows its use in horizontal and vertical machining centers with closed spindle stocks. The “high-Torque” option gives 14 Nm motor torque (S1) and allows to carry even large grinding wheels.

As a result, the user gets an ultra-precision spindle solution for manufacturing optical components applicable to ultra-precision and CNC machining centers.

… according to our slogan: “Ultra-Precision meets Industrial Grade

ASD-Px/ ASD-PH63M – At a glance

Flyer ASD-Px_ASD-PH63M_en

Body – / Flange Diameter:

Max. Speed:

Tool Interface:


“High-Torque” Option (CNC):

“Ultra-Precision” Option (UP):

Rotary Encoder, Axis Mode:

Alternatives, absolute:

Rotary Encoder, Spindle Mode:

3rd Encoder Option:

Rotary Feedthrough Medium:



175 mm / 214.5 mm

10,000, 12,000 rpm (other spindle speeds on request)

HSK-A63, manual

Permanentmagnet-Synchron, 6-Poles, 3 Phases

13.5 Nm

6.5 Nm

Optical 1VSS SinCos, 11,840 Lines + Zero Flag 1)

BiSS-C, FANUC, Mitsubishi-2/4, DRIVE-CLiQ

GMR 1 VSS SinCos, 253 Lines + Zero Flag 2)

1) or 2)

Vacuum, Air, Oil-Air (Option: for cutting fluid, 80 bar max)

500 mm

62 kg

*) can be omitted for absolute rotary encoder for axis operation

  • High-Torque Motor

The High-Torque Motor Option gives 13.5 Nm constant motor torque and allows the use of large grinding wheels with our ASD-PH63M.

  • Absolute Optical Rotary Encoder 

Replacing the standard optical incremental encoder with an absolute encoder with serial protocol allows spindle speeds of up to 28.000 rpm and makes the otherwise required spindle mode encoder redundant. Available serial protocols are:

– Biss-C

– Mitsubishi 2-/4-wire

– Fanuc

– Drive-CliQ

  • Coolant-Through-Shaft

A rotary feedthrough for coolant at up to 80 bar can be offered.

  • Cross Table Model

For their use with horizontal machining centers our ASD-Px and ASD-Ph63M can be offered with a spindle mount that allows an operation without a spindle stock. A diaphragm at the rear end of the spindle block increases the stiffness of the spindle clamp.

  • Download Installation Drawing

Download and safe the Spindle Installation Drawing for our ASD-PH63M and ASD-Px

  • ASD-Px – At a Glance
  • Error Motion

Definition: The value of the so called Error-Motion includes any synchronous and asynchronous spindle error from the theoretical perfect axis of rotation, but without the fundamental (fundamental = run-out)

To perform such a Spindle Error Analysis (SEA) a precisely ground ball is attached to the shaft and one or more gauges measure the radial/axial motion of it. As the roundness of such a SEA-ball (artefact) is much worse than the spindle error itself it becomes clear that an error-separation of spindle and artefact has to take place. This can either be done with a reversal FFT Method where the artefact and the probe has to be rotated by 180° for a second measurement or a multi-probe complex FFT analysis.

Levicron has developped mathematical methods and test benches for the multi-probe measurement of Spindle Motion Errors. As rotation speeds for Levicron products exceed the technical capability of any commercially available solution Levicron developped tailor made hard- and software to verify their products Error-Motion specifications. Our tool spindle models ASD-H25, ASD-H25A and ASD-Cx are specified and verified with a Spindle Motion Error of less than 30 nm, our ASD-Px and ASD-PH63M come with a verified error in motion of under 15 nm.

However the Measurement to the right showing the spindle axial error makes clear that with 8 nm PV this value often is lower and thus guarantees ultra-precision machining and work-holding.

  • Axial Shaft Growth and Spindle Soak Time

As it can be seen on the test results to the right our high-efficient thin-film liquid cooling technology gives a spindle soak time from cold and standstill to 10.000 rpm and warmed through of under 9 minutes. This allows a stationary operation after this time at the same speed and is industry leading.

The spindle design itself also compensates for thermal axial growth and axial growth resulting from centrifugal load and gives a total axial shaft displacement from cold and standstill to 10.000 rpm and warmed through of under 0.8 micron. Like our tool spindles ASD-H25/A and ASD-Cx the centrifugal load on the shaft causes the shaft to grow back into the spindle housing where the thermal load then causes a compensating growth in the opposite direction.

For the user this means that even right after ramping up the spindle he can machine within 0.8 micron, and after 9 minutes after spindle start he can be sure about a 100% stationary operatin.