Renishaw MP250 User manual

MP250 machine tool probe system
Installation guide
H-5500-8504-05-A

Renishaw part no: H-5500-8504-05-A
First issued: 11.2008
Revised: 01.2018
© 2008–2018 Renishaw plc. All rights reserved.
This document may not be copied or reproduced
in whole or in part, or transferred to any other
media or language, by any means, without the
prior written permission of Renishaw plc.
The publication of material within this document
does not imply freedom from the patent rights of
Renishaw plc.

i
Contents
Before you begin .............................................................1.1
Before you begin ............................................................1.1
Disclaimer ..............................................................1.1
Trade marks .............................................................1.1
Warranty................................................................1.1
Changes to equipment .....................................................1.1
CNC machines ...........................................................1.1
Care of the probe .........................................................1.1
Patents .................................................................1.2
EU declaration of conformity ...................................................1.3
FCC Information to user (USA only) .............................................1.3
WEEE directive .............................................................1.3
Safety ....................................................................1.4
MP250 basics ................................................................2.1
Introduction ................................................................2.1
Re-orientation of the probe ....................................................2.2
Switch-on delay .............................................................2.2
Immunity to false trigger ......................................................2.2
Measurement cycles ........................................................2.3
Trigger speed ..............................................................2.3
MP250 dimensions ..........................................................2.4
MP250 probe specification ....................................................2.5
Recommended styli..........................................................2.6
System installation ...........................................................3.1
Installing the MP250 .........................................................3.1
Preparing the MP250 for use ..................................................3.2
Fitting the stylus ..........................................................3.2
Fitting the MP250 into a probe socket .........................................3.3
Mounting the MP250 probe to the probe socket .................................3.4
Stylus configurations .........................................................3.5

MP250 installation guide
ii
Contents
Screw torque values .........................................................3.5
Calibrating the MP250........................................................3.6
Why calibrate a probe? ....................................................3.6
Calibrating in a bored hole or on a turned diameter...............................3.6
Calibrating in a ring gauge or on a datum sphere ................................3.6
Calibrating the probe length .................................................3.6
Calibration feedrate and rotary axes ..........................................3.7
Calibration of each MP250 operating configuration ...............................3.7
HSI or HSI-C interface........................................................3.8
Maintenance .................................................................4.1
Maintenance ...............................................................4.1
Diaphragm replacement ......................................................4.2
MP250 diaphragms .......................................................4.2
Fault-finding .................................................................5.1
Parts list .....................................................................6.1

1.1
Before you begin
Changes to equipment
Renishaw reserves the right to change equipment
specifications without notice.
CNC machines
CNC machine tools must always be operated by
fully trained personnel in accordance with the
manufacturer’s instructions.
Care of the probe
Keep system components clean and treat the
probe as a precision tool.
Before you begin
Disclaimer
RENISHAW HAS MADE CONSIDERABLE
EFFORTS TO ENSURE THE CONTENT OF THIS
DOCUMENT IS CORRECT AT THE DATE OF
PUBLICATION BUT MAKES NO WARRANTIES
OR REPRESENTATIONS REGARDING
THE CONTENT. RENISHAW EXCLUDES
LIABILITY, HOWSOEVER ARISING, FOR ANY
INACCURACIES IN THIS DOCUMENT.
Trade marks
RENISHAW and the probe symbol used in the
RENISHAW logo are registered trade marks of
Renishaw plc in the United Kingdom and other
countries. apply innovation and names and
designations of other Renishaw products and
technologies are trade marks of Renishaw plc or
its subsidiaries.
All other brand names and product names used
in this document are trade names, trade marks, or
registered trade marks of their respective owners.
Warranty
Equipment requiring attention under warranty
must be returned to your equipment supplier.
Unless otherwise specifically agreed in writing
between you and Renishaw, if you purchased
the equipment from a Renishaw company, the
warranty provisions contained in Renishaw’s
CONDITIONS OF SALE apply. You should consult
these conditions in order to find out the details
of your warranty but, in summary, the main
exclusions from the warranty are if the equipment
has been:
•neglected, mishandled or inappropriately used;
or
•modified or altered in any way except with the
prior written agreement of Renishaw.
If you purchased the equipment from any other
supplier, you should contact them to find out what
repairs are covered by their warranty.

MP250 installation guide
1.2
Before you begin
Patents
Features of the MP250 probe and other similar
Renishaw products, are the subject of one or
more of the following patents and/or patent
applications:
CN 101142461
CN 101171493
EP 1866602
EP 1880163
EP 2154471
IN 6963/DELNP/2007
IN 8669/DELNP/2007
JP 5283501
JP 5308811
JP 5611297
US 7603789
US 7792654
US 8140287

1.3
Before you begin
C
FCC Information to user (USA
only)
47 CFR Section 15.19
This device complies with part 15 of the FCC
Rules. Operation is subject to the following two
conditions:
1. This device may not cause harmful
interference, and
2. This device must accept any interference
received, including interference that may
cause undesired operation.
47 CFR Section 15.21
The user is cautioned that any changes or
modifications not expressly approved by
Renishaw plc or authorised representative could
void the user’s authority to operate the equipment.
47 CFR Section 15.105
This equipment has been tested and found to
comply with the limits for a Class A digital device,
pursuant to part 15 of the FCC Rules. These limits
are designed to provide reasonable protection
against harmful interference when the equipment
is operated in a commercial environment. This
equipment generates, uses, and can radiate
radio frequency energy and, if not installed
and used in accordance with the instruction
manual, may cause harmful interference to radio
communications. Operation of this equipment
in a residential area is likely to cause harmful
interference in which case the user will be
required to correct the interference at his own
expense.
EU declaration of conformity
Renishaw plc declares that the MP250 complies
with the applicable standards and regulations.
Contact Renishaw plc or visit
www.renishaw.com/mp250 for the full EU
declaration of conformity.
WEEE directive
The use of this symbol on Renishaw products
and/or accompanying documentation indicates
that the product should not be mixed with
general household waste upon disposal. It is the
responsibility of the end user to dispose of this
product at a designated collection point for waste
electrical and electronic equipment (WEEE) to
enable reuse or recycling. Correct disposal of
this product will help to save valuable resources
and prevent potential negative effects on the
environment. For more information, please
contact your local waste disposal service or
Renishaw distributor.

MP250 installation guide
1.4
Before you begin
Safety
In all applications involving the use of machine
tools or CMMs, eye protection is recommended.
Information to the machine supplier/
installer
It is the machine supplier’s responsibility to ensure
that the user is made aware of any hazards
involved in operation, including those mentioned
in Renishaw product literature, and to ensure
that adequate guards and safety interlocks are
provided.
Under certain circumstances, the probe signal
may falsely indicate a probe seated condition. Do
not rely on probe signals to halt the movement of
the machine.
Information to the equipment installer
All Renishaw equipment is designed to comply
with the relevant EU and FCC regulatory
requirements. It is the responsibility of the
equipment installer to ensure that the following
guidelines are adhered to, in order for the product
to function in accordance with these regulations:
•any interface MUST be installed in a position
away from any potential sources of electrical
noise, i.e. power transformers, servo drives
etc.;
•all 0 V/ground connections should be
connected to the machine “star point” (the
“star point” is a single point return for all
equipment ground and screen cables). This is
very important and failure to adhere to this can
cause a potential difference between grounds;
•all screens must be connected as outlined in
the user instructions;
•cables must not be routed alongside high
current sources, i.e. motor power supply cables
etc., or be near high-speed data lines;
•cable lengths should always be kept to a
minimum.
Equipment operation
If this equipment is used in a manner not specified
by the manufacturer, the protection provided by
the equipment may be impaired.

2.1
Introduction
Renishaw’s second generation MP250 ultra
compact probe for tool and cutter grinding
machine sets new standards for reliability and
robustness,
Easily identified by the C marking on the probe
body (see figure below), the second generation
MP250 continues to successfully combine
minaturisation of the popular LP2 with high
accuracy of the RENGAGE™ technology, to
provide users with a simple upgrade to solid-state
strain gauge technology and all the associated
benefits this brings:
•excellent 3D performance to allow probing of
contoured surfaces;
•improved repeatability in all probing directions;
•low pre-travel variation to provide high
accuracy, even when used with long styli;
•a proven improvement in life;
•compact and robust design; ideal for grinding
machine applications;
•resistance to shock and false triggering
through the use of digital filtering.
MP250 basics
The second generation MP250 is compatible for
application with both HSI and HSI-C interfaces.
Full functional capability of second generation
MP250 is realised when it is used in conjunction
with the HSI-C interface. Application with HSI-C
enables the user to select a suitable level of
immunity to false triggers, caused by machine
vibrations or accelerations.
In addition to providing high accuracy
measurement on your grinding machine, the
MP250 also offers:
•A reduced need to calibrate:
Whilst pre-travel variation is not regarded as
a form of measurement error, since it can
be easily compensated for by calibrating the
probe, on complex parts it may be necessary
to probe in many different directions.
Calibrating the probe in each direction can be
extremely time consuming.
The MP250 has almost no pre-travel variation
(typically ±0.25 µm (10.00 µin) in the X, Y
plane and ±1.00 µm (40.00 µin) 3D). This
allows the machine to be programmed to
drive the stylus onto any part at any angle
such that it touches the component normal
to the surface. It is NOT NECESSARY to
re-calibrate the probe in each direction it is to
be used. Once calibrated, the probe can be
used in ANY direction. However, if the probe is
re-orientated between measuring points, some
form of calibration should be considered at
each orientation due to the effect of gravity on
the stylus.
For further information about calibration, refer
to page 3.6 “Calibrating the MP250”.
second generation MP250
with C identification
marking on probe body

MP250 installation guide
2.2
MP250 basics
Re-orientation of the probe
If an MP250 is fitted with a long or ‘heavy’ stylus,
and its orientation is changed from horizontal to
vertical or vice-versa (i.e., such as on a 5-axis
machine with a swivelling head), it is possible for
the probe to trigger and remain triggered requiring
a probe reset. It is also possible, if the MP250
is fitted with a long or ‘heavy’ stylus, mounted
horizontally and then rotated about its own axis,
for the probe to trigger and remain triggered. It is
recommended that the probe inhibit function is
used to turn off power to the MP250 during every
re-orientation move. Once the re-orientation move
is complete, the probe inhibit function should be
removed so that power to the probe is restored.
The probe will then take a minimum of
0.4 seconds before it is ready to measure and
must remain stationary during this period. In
order to reset correctly, the probe stylus must be
in free air and not in contact with the workpiece,
or anything else, when the inhibit function is
removed.
For further details of the probe inhibit function, see
the HSI hard-wired system interface installation
guide (Renishaw part no. H-5500-8554) or
the HSI-C hard-wired system interface -
configurable installation guide (Renishaw part no.
H-6527-8501).
Switch-on delay
To ensure that the probe activates correctly, it is
important to make sure that it is stationary when it
is switched on. If the probe is not stationary during
the start sequence, then there is a possibility
that the probe could be initialised in the incorrect
position and produce a permanently triggered
output.
NOTES:
The probing program on the machine will need to
take account of the switch-on delay.
The stylus must not be deflected when the probe
is switched on, otherwise the system will not
initialise correctly and may appear permanently
triggered.
During the initialisation period just after switch
on, the probe status output is triggered for safety
reasons.