PH20 is a dynamic measuring head and probe system from Renishaw. It is a revolutionary product designed to maximise measurement throughput whilst maintaining high system accuracy for basic entry level measurement systems.
PH20 incorporates Renishaw's long established TP20 probe system into a revolutionary motorised head system to give unprecedented touch-trigger measurement capability. Unlike conventional touch-trigger measurement methods which rely on increased speed of the CMM's 3 axes to measure quickly, PH20 uses head motion to minimise dynamic errors introduced by machine motion at high measurement speeds.
The PH20 head and CMM system are operated through the UCCserver which uses I++DME command protocol to communicate between the system application software and the Renishaw controller. The CMM and PH20 head are controlled by the appropriate Renishaw controller, via its standard connections.
Net weight: 810 g
PH20 head axis range
The PH20 head has two rotary axes (A and B) and is normally mounted on the CMM quill to create a 5-axis measuring system. The PH20 B-axis is mounted on the CMM quill and can rotate continuously in both directions. The A-axis, which is orthogonal to the B-axis, has ±115° of travel. The head can only be mounted in the vertical orientation shown below.
TP20 stylus modules
PH20 has an integrated TP20 body that is capable of touch-trigger measurement when used with a suitable stylus module. The probe design utilises the existing range of the TP20 stylus modules, however the TP20 extended force module is not suitable for use on PH20.Each probe module, which houses the kinematic switching touch sensor mechanism, carries the stylus assembly and provides overtravel in the X, Y and +Z axes (–Z is offered when using the TP20 6-way probe module). Incorporating an M2 stylus mounting, each probe module is compatible with Renishaw's comprehensive range of M2 styli.
Designed to minimise the possibility of probe module misalignment generating a probe ‘seated' signal, the probe module is held in position by a magnetically retained, highly repeatable kinematic coupling. Electrical contact pins conduct the probe sense voltage through the coupling.
Trigger force options
The standard force probe module is suitable for most applications (when used with the recommended stylus range), but sometimes the effects of stylus length and mass, combined with machine acceleration and vibration, can cause the probe to false trigger (these are referred to as ‘false triggers').
To allow the PH20 to be used on co-ordinate measuring machines where acceleration forces or vibration would otherwise result in spurious triggers, a choice of higher force probe modules is available. A low force probe module is also available for measurement of delicate materials. Refer to the applications guide later in this document for information on how to select the correct probe module for your application.
The type of probe modules supplied with your probe will be clearly marked on each probe module's front ring. The probe modules also carry a colour-coded front cap as follows:
NOTE:The extended force module is not suitable for use with the PH20 system.
TP20 module kits
The following TP20 probe module kits are available from your supplier for use with PH20:
Manually mounting / removing the stylus modules to / from PH20
It is not recommended to manually remove and refit a probe module to PH20. If it is absolutely neccessary to manually remove the probe module from PH20 it should only be done in certain orientations. Please see the image below.
To fit the probe module and stylus onto the probe body, carry out the following procedure:
Manually mounting / removing the stylus from the stylus module
To fit a stylus onto the probe module, carry out the following procedure:
NOTE: For advice on both stylus and probe module selection, refer to the applications guide later in this publication.
TCR20 rack kit
The TCR20 rack, which can be easily mounted onto a CMM, is designed to securely hold stored probe modules for automatic changing. TCR20 protects stored probe modules from airborne contaminants that may be present within the working environment and also features an integrated tip datum artefact.