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PHS-2 servo head

PHS-2 is designed to meet the arduous requirements of 'body-in-white' measurement, where fine angular position and long reach are needed.


The PHS-2 servo positioning head features continuous servo drive in two axes, enabling the probe configuration to be positioned at almost any angle.

The PHS-2 head is driven to approximately the required position and, when a probing point is taken, the axes of the head latch simultaneously with the axes of the CMM to give accurate measurements.

A range of different probes can be fitted and automatically exchanged. These include touch-trigger probes and third-party laser/optical measurement sensors.

Extra-long extensions allow the Renishaw trigger probes to reach normally inaccessible features.

The head is protected by a built-in electronic over torque that disengages the head and signals the machine to stop in the event of a collision.

Operating temperature

15 °C to 40 °C (50 °F to 104 °F)

Weight *

3 kg (6.6 lb)

Carry capability

Combined probe and extension mass of 1 kg (2.2 lb)

Maximum torque

2 Nm

Mechanical clutch slip

3 Nm ±0.5 Nm

Movement speed

150 °/s maximum, 70 °/s typical

Arm rotation angle

D-axis: ±184°

E-axis: ±184°

Angular resolution

0.2 arc second (equivalent to 0.1 µm at 100 mm radius)

Collision protection

Electronic over torque

Suitable head interface

PHS-2 interface card / OEM controller

Changer rack system


* including probe extension and kinematic joint

PHS-2 arm


PHS-2 interface card

The PHS-2 head is controlled by the head interface card in the CMM controller. The card handles communications and conditions the signals between the head and the CMM controller. The PHS-2 interface card does not handle probing system signals.

Kinematic mount

A kinematic mount (KM1 or KM2) allows quick fixing of the head to the machine.

KM1 features through-quill cabling.

KM2 allows for cabling to run outside the CMM quill.

ACR2 autochange rack

PHS-2 ACR2 installation

The ACR2 autochange system is an arm-changing system for the PHS-2 servo positioning head system. It allows probe extensions or probe adapter arms to be exchanged to suit the probing task required.

Arms are locked or unlocked from the head by motion of the machine itself. The head engages a rack port and the machine drives the port: up to unlock an arm, or down to lock it in position.

No power connections or signal connectors to the rack are necessary, making installation very simple.

The ACR2 is supplied as pairs of rack ports which are mounted onto a suitable fixture supplied by the OEM. The system is modular and any number of port pairs can be used anywhere on the CMM.

Extended warranty

For peace of mind a 3-year warranty is available for your new CMM products during the first 3 months from purchase. Contact your vendor.