This presentation is made in an effort to impart information regarding the techniques used for the calibration of coordinate measuring machines. These versatile machines are today being used for the inspection of very precise and accurate mechanical components manufactured by keeping in view advanced geometrical dimensioning and tolerancing techniques.
A Coordinate measuring machine is an electromechanical system design to perform coordinate metrology.
CMMs are also considered as transducers that can convert physical measurements into electrical signals.
They are versatile in their capability to record measurement of complex profiles with high sensitivity (0.0025 mm) and speed.
Coordinate metrology is concerned with the measurement of the actual shape and dimensions of an object and comparing these with the desired shape and dimensions.
In this connection, coordinate metrology consists of the evaluation of the location, orientation, dimensions, and geometry of the part or object.
A Coordinate Measuring Machine (CMM) is an electromechanical system designed to perform coordinate metrology.
BAHIR DAR UNIVERSITYBAHIR DAR INSTITUTE OF TECHNOLOGY (BiT)FACULTY OF MECHANICAL AND INDUSTRIAL ENGINEERING Rapid Prototyping & Reverse Engineering [MEng6123]
Reverse Engineering
Coordinate Measuring Machine (CMM)
Coordinate Measuring Machines (CMM)
A Coordinate Measuring Machine (CMM) is an electromechanical system designed to perform coordinate metrology.
CMM is a device for measuring the physical geometrical characteristics of an object.
CMM Applications
Types of CMM
Cantilever Type
Moving bridge type
Fixed bridge type
Column type
Gantry type
Horizontal arm type
Portable type
1. Cantilever Type of CMM
2. Moving Bridge type
3.Fixed bridge type
4. Column type CMM
5. Horizontal arm type CMM
6. Gantry type CMM
Types of Probe
Contact probe
Hard probe
Switching probes
Measuring probes
Non-contact probes
Laser probe
Vision probe
Hard Probe
It has a variety of probe tip shape and size based on the application.
Ball/Spherical shape probe used for establishing surface locations.
Tapered or conical probe used for locating holes.
Cylindrical probe used for checking slots and holes in sheet metal.
Switching Probes
3. Measuring Probes
2. Vision Probe
CAUSES OF ERRORS IN CMM
A Coordinate measuring machine is an electromechanical system design to perform coordinate metrology.
CMMs are also considered as transducers that can convert physical measurements into electrical signals.
They are versatile in their capability to record measurement of complex profiles with high sensitivity (0.0025 mm) and speed.
Coordinate metrology is concerned with the measurement of the actual shape and dimensions of an object and comparing these with the desired shape and dimensions.
In this connection, coordinate metrology consists of the evaluation of the location, orientation, dimensions, and geometry of the part or object.
A Coordinate Measuring Machine (CMM) is an electromechanical system designed to perform coordinate metrology.
BAHIR DAR UNIVERSITYBAHIR DAR INSTITUTE OF TECHNOLOGY (BiT)FACULTY OF MECHANICAL AND INDUSTRIAL ENGINEERING Rapid Prototyping & Reverse Engineering [MEng6123]
Reverse Engineering
Coordinate Measuring Machine (CMM)
Coordinate Measuring Machines (CMM)
A Coordinate Measuring Machine (CMM) is an electromechanical system designed to perform coordinate metrology.
CMM is a device for measuring the physical geometrical characteristics of an object.
CMM Applications
Types of CMM
Cantilever Type
Moving bridge type
Fixed bridge type
Column type
Gantry type
Horizontal arm type
Portable type
1. Cantilever Type of CMM
2. Moving Bridge type
3.Fixed bridge type
4. Column type CMM
5. Horizontal arm type CMM
6. Gantry type CMM
Types of Probe
Contact probe
Hard probe
Switching probes
Measuring probes
Non-contact probes
Laser probe
Vision probe
Hard Probe
It has a variety of probe tip shape and size based on the application.
Ball/Spherical shape probe used for establishing surface locations.
Tapered or conical probe used for locating holes.
Cylindrical probe used for checking slots and holes in sheet metal.
Switching Probes
3. Measuring Probes
2. Vision Probe
CAUSES OF ERRORS IN CMM
1. Measuring the angle of a component.
2. Checking the sloping angle of a vee-block.
3. Measuring the angle of a cone or taper gauges.
4. Precise angular settings for machining operations.
This presentation gives the information about Screw thread measurements and Gear measurement of the subject: Mechanical measurement and Metrology (10ME32/42) of VTU Syllabus covering unit-4.
Presentation gives brief overview of Linear and angular measurements related to engineering, different types of instruments used for Linear and angular measurements such as vernier calipers ,micrometers,their types,non precision measuring instruments etc.
Uncertainty of Coordinate Measuring MachinesHassan Habib
The presentation was delivered in the presentation of a conference paper at ICAYS (International Conference in Aerospace for Young Scientists) at Beihang University, Beijing, China. The topic takes into account the critical factors that effect the CMM measurements. The presentation represents the way of Guide to Expression of Uncertainty Measurement (GUM). All the formulas taken for the calculation are based on literature review.
1. Measuring the angle of a component.
2. Checking the sloping angle of a vee-block.
3. Measuring the angle of a cone or taper gauges.
4. Precise angular settings for machining operations.
This presentation gives the information about Screw thread measurements and Gear measurement of the subject: Mechanical measurement and Metrology (10ME32/42) of VTU Syllabus covering unit-4.
Presentation gives brief overview of Linear and angular measurements related to engineering, different types of instruments used for Linear and angular measurements such as vernier calipers ,micrometers,their types,non precision measuring instruments etc.
Uncertainty of Coordinate Measuring MachinesHassan Habib
The presentation was delivered in the presentation of a conference paper at ICAYS (International Conference in Aerospace for Young Scientists) at Beihang University, Beijing, China. The topic takes into account the critical factors that effect the CMM measurements. The presentation represents the way of Guide to Expression of Uncertainty Measurement (GUM). All the formulas taken for the calculation are based on literature review.
After studying this chapter, the reader will be able to
• understand the importance of metrology
• appreciate the significance of inspection
• appreciate the concepts of accuracy and precision
• explain the objectives of metrology and measurements
• understand the general measurement concepts
• elucidate the different sources and types of errors
• compare the different types of measurements
Instruments for linear and angular measurements
This presentation covers the basics of meter testing including why we test; how to test; types of meter tests; how utility tests differ from customer request tests; in-service testing; and what to do with the test data—presented at NC Meter School 2022.
This presentation explains why we test, types of tests and requirements, and data tracking. It's anything and everything you wanted to know about meter testing!
The analyst is required to analyze a number of QC samples throughout the run where there are decisions to be made based on a window of acceptance for each QC sample analyzed.
Customers always have the right to request a meter test.
Some utilities and some jurisdictions allow for testing at the customer site, others require a test in a laboratory environment.
Some allow the customer to witness the test and others require the utility commission to witness the test.
Utilities must show that the meter tests well and must demonstrate that they have a test program in place to ensure the meters in service are performing well.
This presentation will demonstrate:
Why do we test?
How do we test?
What types of meter tests are there?
How do utility tests differ from customer request tests?
What is In-Service Testing?
How do we know meter tests are good?
What do we do with the test data?
As many utilities have elected to deploy advanced metering systems and millions of new solid-state, microprocessor based end-points with communications under glass, a dramatic shift has begun regarding where metering resources are being deployed and what they are doing. This presentation will highlight the new value proposition for metering personnel at their respective utility companies in a post-AMI World. Examples of issues which have arisen or been identified over the course of various deployments and in the immediate aftermath of an AMI deployment.
APPLICATION OF MECHATRONICS IN COORDINATE MEASURING MACHINE.USE OF MULTI-SENSOR TECHNOLOGY.CMM IS USED TO MEASURE COORDINATE OF A WORKPIECE WITH THE HELP OF PROBE.CMM CAN BE CONTROLLED WITH THE HELP OF NUMERICAL CONTROL. INTRODUCTION TO 5 AXIS TECHNOLOGY.
ADVANTAGES OF CMM.TYPES OF CMM.
The presentation deals with the basics of Dimensional Metrology.
The presentation includes the basic terminologies , including the following:
Measurement uncertainty: Understanding how to evaluate and report measurement uncertainty, which is the level of confidence in a measurement result.
Statistical analysis: Knowledge of basic statistical concepts, such as mean, standard deviation, and normal distribution, and their use in dimensional metrology.
Tolerance analysis: Understanding of tolerance limits, and how to apply them in dimensional measurements to determine if a part is acceptable or not.
Measurement systems analysis: Knowledge of how to evaluate the performance of measurement systems and identify sources of error.
The presentation depicted herein presents briefly an introduction of acceptance sampling along with some major differences amongst the widely used sampling standards.
Acceptance Sampling standards comparison. MIL-STD-105E, MIL-STD-1916, ISO 2859, ISO 3951. About AQLs and OC Curves.
The presentation takes into account widely used surface finishing processes including electroplating, anodizing, alodining, cadmium plating, zinc plating, phosphating, passivation
It is a rudimentary emphasis on the importance of Child Labor. It concerns itself with some of the labor laws of Pakistan and points out how great the issue is world wide.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
2. Things we are going to learn
• About Coordinate Measuring Machines (CMMs)
• Measurements
• What is a CMM?
• How does a CMM work?
• Calibration
• What is calibration?
• Calibration standards for CMM
• Calibration procedure for CMM
• E&R Test
• Introduction
• Definition of errors & Material Standard
• Choice of Artifacts
• Preliminary Setup
• Measurements for error in length
• Calculation of results
• Probing test error
3. Things we are going to learn
• Laser Interferometery
• Introduction
• Principle of Laser Interferometers
• Widely used interferometers in the market
• Components of Laser interferometer
• Preparing the machine for calibration
• Definition of geometrical deviations to be measured
• Setting up the laser
• Set up the measurements/optics
• Collect the data and analyze according to international
standards
• Compensation of results
• Some Post Checks
4.
5. • Beauty is in the perfection of creation. Humans have been
creating since their presence on earth
• However, accuracy of these measurements has evolved
over time and so has the beauty they have created
• The earliest examples of accuracy can be found in the
construction of Great Pyramids (The difference between
height of two opposite corners at its base is 13 mm.)
About Coordinate Measuring Machines (CMM)
Measurements
6. About Coordinate Measuring Machines (CMM)
Measurements
Evolution of Measuring Instruments
Cubit
Micrometer
Gauge
Blocks
Length
Comparator
Gauges and
Dial
Indicators
Visual
Inspection
machines
Universal
Measuring
Machines
CMM
7. About Coordinate Measuring Machines (CMM)
What is a CMM?
• Modern machines used for very accurate and precise
measurements
• CMM works on the principle of Coordinate Measuring i.e.
measurement based on collection of data points taken in a
Cartesian Coordinate System
• “The primary function of a CMM is to measure the actual
shape of a work piece, compare it against the desired
shape, and evaluate the metrological information such as
size, form, location, and orientation.” [Ref: Read ‘Notes’]
8. About Coordinate Measuring Machines (CMM)
What is a CMM?
• CMM can measure complex geometrical tolerances and
deviations on manufactured parts
• The accuracy of these machines today are closer to 1µm
• CMMs are capable of measuring point to point coordinates
and they can also analyze continuous data points using
advanced touch probes (SP600 and PH20)
• CMMs are extensively used in Aerospace and automotive
sectors where increased accuracy of measurement is
required
Features
12. Calibration
What is calibration?
• It is the process of verifying and adjusting the accuracy
of Measuring & Monitoring Equipment (MME) and
machines by comparing them with standards of known
accuracy.
• The adjustment of instruments is performed by
compensating the errors into the instrument.
• OEM (Original Equipment Manufacturer) of the
instrument usually defines calibration interval,
environment of usage and tolerance limits within which
the instrument will conform to its performance standard.
• It is performed in regular intervals so as to ensure that
the instrument is reliable.
13. Calibration
What is calibration?
• Calibration provides the confidence that their accuracy
is as per the given specifications of OEM.
• It ensures the repeatability of the measurements taken
by the equipment.
• The uncertainty is kept at minimum level further
building the confidence of measurements.
• It is performed in regular intervals so as to ensure that
the instrument is reliable.
• Calibrating instruments through certified bodies
increases the confidence level of customers for your
organization.
Importance of Calibration
14. Calibration
Calibration of CMMs
• The calibration of CMM benefits as per the stated
benefits of calibration.
• For a CMM there can be number of sources of error that
will remain undetected thereby nullifying usability.
• The calibration of CMM is performed according to the
guidelines provided in ISO 10360-2.
• National Physics Laboratory (NPL) has also provided
standard procedures for verification of performance
level of CMMs by detailing guidelines. These
guidelines are provided to perform E&R test on the
machine using organizational standards used for
calibration.
16. Calibration
Calibration of CMMs
• In the scope of this presentation we are going to study
two standards of calibration of CMMs:
• E&R test for verification of length measurements
• Verification and Compensation of geometric errors
with Laser Interferometry
17. Calibration
Calibration Procedure for CMMs
Choice of
Artifacts
Preliminary
Setup
Length
Measurement
Calculation of
results
Probing Test
Procedure of verification for length measurement through E&R test
20. E&R Test
Introduction
• The tests help in demonstrating traceability to national
standards and estimating the accuracy of measurements
made with three dimensional CMMs for maintaining
confidence and reliability in the measurements.
• The tests also indicate health of the machine that is
necessary to perform maintenance.
21. E&R Test
Introduction
• Wear of components - the guide ways, the scales, the
probe system and the qualification sphere;
• Environment in which the CMM operates - the ambient
temperature, temperature gradients, humidity and
vibration;
• The probing strategy used – the magnitude and direction
of the probe force, the type of probe stylus used and the
measuring speed of the probe; and
• Characteristics of the workpiece – elasticity, surface
roughness, hardness and the mass of the component
Possible sources of error in CMM
22. E&R Test
Definition of Errors & material standard
• ISO 10360 strongly recommended that the material
standard should be either a step gauge, end bar or a
series of gauge blocks conforming to ISO 3650
• The material standard of size used for the tests must be
calibrated.
• The uncertainty of calibration must be taken into
consideration and the calibrations must be traceable to
the relevant national standard.
23. E&R Test
• It is the term that specifies the length measuring
accuracy of their CMM. EMPE,L is defined as the extreme
value of the error of indication of a CMM for size
measurement, permitted by specifications, regulations
etc.
• It is measured in one of the following ways:
• a) EL,MPE = ± minimum of (A + L/K) and B
• b) EL, MPE = ± (A + L/K)
• c) EL, MPE = ± B
where
A is a positive constant, expressed in micrometres and supplied by the
manufacturer;
K is a dimensionless positive constant supplied by the manufacturer;
L is the measured size, in millimetres; and
B is the maximum permissible error
a)
b)
c)
Definition of Errors & material standard
24. E&R Test
• The E&R test involves two types of measurement errors.
• Volumetric length measuring error E
• It applies to all measurements of distances, diameters, and positional
tolerances.
• Volumetric Probing Error P
• It applies to all Form measurements of straightness, flatness, Cylindricity,
roundness and free form tolerances.
Definition of Errors & material standard
25. E&R Test
Choice of artifacts
• The choice of artifacts depend on the recommendations
from the manufacturer and or the size of you CMM.
Various types of artifacts are available for verification
and re-verification, and interim check tests, some of
them are:
• Step Gauge
• Length bar
• Ball Plate
• Hole Plate
• Purpose made test piece
26. E&R Test
Definition of Errors & material standard
Comparison between different artifacts
27. E&R Test
Preliminary Setup
• Below are some of the pre-requisites for performing the
E&R test:
• CMM must be operated in accordance with the
procedure stated in the instruction manual
including machine start up, probe qualification and
probe configuration.
• Manufacturer supplied test sphere must be used.
• Limits for permissible environmental conditions,
such as temperature conditions, air humidity and
vibration that influence the measurements are
usually specified by the manufacturer
• Cleaning of stylus tip;
• Thermal stability of the probing system
• Weight of stylus system and/or probing system;
and location, type, number of thermal sensors
28. E&R Test
• For the E test a set of 5 length gauges is measured three
times in 7 spatial positions.
• Total number of measurements:
• 3 x 5 x 7 = 105
• 100 % of results must be in the specified limits
• The seven spatial positions are:
• Along x-axis
• Along y-axis
• Along z-axis
• Along s-partial 1 (Diagonal in XY)
• Along s-partial 2 (Diagonal in YZ)
• Along s-partial 3 (Diagonal in XZ)
• Along s-partial 4 (Diagonal in XYZ)
Measurements for error in length
E Test Sample positions
30. E&R Test
Calculation of results
• For each of the 105 measurements the error of length
measurement, EL is calculated.
• Its value is the absolute value of the difference between
the indicated value of the relevant test length and the
true value of the material standard.
• Sample results are shown:
34. E&R Test
Calculation of results
• From the results it can be seen that some of the thirty-
five test lengths have values of the error of length
measurement
• These values will have to be measured again ten times
each at the relevant configuration
Interpretation of the results
35. E&R Test
Probing Test Error
• This test of the CMM probing system is used to
establish whether the CMM is capable of measuring
within the manufacturer‘s stated value of PFTU, MPE by
determining the range of values of the radial distance r
when measuring a reference sphere.
Where,
P: associated with the probing system
F: apparent Form error
T: contact probing (that is to say Tactile)
U: single (that is to say Unique)
• It is advisable to carry out this test before an acceptance
or re-verification test.
Introduction
36. E&R Test
Probing Test Error
• The sphere supplied by the manufacturer for probe
qualifying purposes (reference sphere) should not be
used for the probing error test.
Introduction
37. E&R Test
Probing Test Error
• The probing error is a positive constant, the value of
which is supplied by the CMM manufacturer.
• The test sphere should be between 10 mm and 50 mm
diameter.
• The test sphere should be mounted rigidly to overcome
errors due to bending of the mounting stem.
• Twenty-five points are measured and recorded. It is a
requirement that the points are approximately evenly
distributed over at least a hemisphere of the test sphere.
• Their position is at the discretion of the user
Procedure
38. E&R Test
Probing Test Error
• one point on the pole (defined by the direction of the
stylus shaft) of the test sphere;
• four points (equally spaced) 22.5° below the pole;
• eight points (equally spaced) 45° below the pole and
rotated 22.5° relative to the previous group;
• four points (equally spaced) 67.5° below the pole and
rotated 22.5° relative to the previous group; and
• eight points (equally spaced) 90° below the pole (i.e., on
the equator) and rotated 22.5° relative to the previous
group.
Measurements
Measurement Pattern
41. E&R Test
Probing Test Error
Interpretation of Results
• If the range rmax - rmin of the twenty-five radial distances
(PFTU) is no greater than the manufacturer‘s stated
value of PFTU, MPE when taking into account the
measurement uncertainty, then the performance of the
probing system is verified
42.
43. Laser Interferomter
Introduction
• As stated before laser interferometer is a higher standard
of measurement that is used for the calibration of CMM
for its geometrical deviations.
• The values from this calibration are also used as
compensations for the deviations in the machine
controller.
• Once these compensations are provided to the controller
all machine errors are compensated and the machine
returns to the factory provided performance standard.
• Laser interferometry has slowly evolved into easy to use
equipment that can help to perform various tasks.
• This type of calibrations all started with Michelson’s
Interferometer
44. Laser Interferomter
Principle
• The working principle of laser interferometers today
used, work on the principle of the Michelson’s
Interferometer.
• The Michelson interferometer is common configuration
for optical interferometry and was invented by Albert
Abraham Michelson.
• Albert Michelson and Edward Morley performed their
famous Michelson-Morley experiment in 1887.
Edward Morley
45. Laser Interferomter
Principle
• Using a beam splitter, a light source is split into two
arms.
• Each of those is reflected back toward the beam splitter
which then combines their amplitudes
interferometrically.
• The resulting interference pattern that is not directed
back toward the source is typically directed to some type
of photoelectric detector or camera.
• Depending on the interferometer's particular
application, the two paths may be of different lengths or
include optical materials or components under test.
Interference Patterns from an
interferometer
Michelson’s Interferometer
47. Laser Interferomter
Principle
• M is partially reflective, so part of the light is
transmitted through to point B while some is reflected in
the direction of A.
• Both beams recombine at point C' to produce an
interference pattern incident on the detector at point E
(or on the retina of a person's eye).
• If there is a slight angle between the two returning
beams, for instance, then an imaging detector will
record a sinusoidal fringe pattern.
• If there is perfect spatial alignment between the
returning beams, then there will not be any such pattern
but rather a constant intensity over the beam dependent
on the differential path length.
Michelson’s Interferometer
50. Laser Interferomter
Components of laser interferometer
• Laser Head
• Environment compensation unit
• Material temperature sensors
• Power Supply
• Air sensors
• Tripod stand with stage
• Laptop with necessary software
• Optics for different measurements
Major Components
51. Laser Interferomter
Preparing the machine for calibration
Preliminary setup
Check the air
filters
•Including
machine filters
and air dryer
filters
Check air tubing
for replacement
•Wet air would
probably
require
replacement of
tubing
Check air
bearings
•They must
have specified
gap of air
cushion
Remove rubber
pads from base
•Removal
makes
foundation stiff
Balance the
machine bed
•Use
inclinometers
Note:
– You can use the master square to balance the z-axis
– Balance the machine on three nodes and remove any redundant
rests from the base
– There should be no turbulence in air. Turbulence will cause laser
error
– The environment must be controlled as much as possible.
52. Laser Interferomter
Definition of geometrical deviations to be measured
Measurements needed for error mapping
• Error mapping is done to calculate the 21 geometric
deviations that can occur in an articulating machine
including CMM and machining centers.
• First these are measured and then compensated using the
appropriate software to the controller of the machine.
• The deviations are majorly of these types:
• Linearity (3)
• Straightness (6)
• Rotation (9)
• Squareness (3)
54. Laser Interferomter
Definition of geometrical deviations to be measured
Geometrical compensation parameters
• Usually the geometric deviations are termed as
compensation parameters and are designated values
such as:
Rxx = Linear straightness in x-axis
Ryy = Linear straightness in y-axis
Rxy = Horizontal straightness of x-axis
Rxz = Vertical straightness of x-axis
Dxy = Yaw of x-axis
Dxz = Pitch of x-axis
.
.
.
.
etc.
55. Laser Interferomter
Definition of geometrical deviations to be measured
Geometrical compensation parameters
• For the complete error map these measurements are to
be compensated in the controller of the machine.
• Software such as Geocomp are used to upload the
valued of these deviations into the controller.
• Two of these measurements can be taken from
inclinometer. These are the straightness of x-axis and y-
axis.
• Rest of the measurements are taken from a laser
interferometer
• The linear straightness of the z-axis can be measured by
using two Dzy measurements.
56. Laser Interferomter
Setting up the laser
Generic Procedure
• Here we will outline a generic procedure to perform the
linear measurement on ML10 laser interferometer of
Renishaw. It will give us an overview of the procedure.
It is similar to that of Agilent laser interferometer.
57. Laser Interferomter
Setting up the laser
Generic Procedure
• First step is to setup the stage on the tripod stand.
Secure and tight it on the stand.
• Position the Laser head on the tripod stand with stage.
• Arrange the laser interferometer according to the
measurement you are about to take.
• Switch on the laser. You have to wait for a specified
time for the laser to get stabilized.
58. Laser Interferomter
Setting up the laser
Generic Procedure
• Align and fix the optics for the measurement in
our case it will be the linear interferometer that
includes linear reflector and linear beam splitter
as well as clamp blocks to fix it on the machine
head.
• Now you have to mount the interferometer on the
machine bed and reflector has to be attached on
machine spindle. Side surfaces of linear beam
splitter and reflector have to be exactly parallel.
Note: In our case the linear interferometer stays stationary while the
splitter moves along the axis.
59. Laser Interferomter
Setting up the laser
Generic Procedure
• The shutter of the laser head can be rotated. Rotate it
so that the laser leaving the head has a reduced beam
diameter.
• Now adjust the tripod so as the spirit level of the tripod
is at the central position.
• Bring closer the reflector to the laser head and observe
a white spot target on the front. Now move the
machine in the x-axis until the beam hits the target.
Shutter at closed position with
no laser emitted
60. Laser Interferomter
Setting up the laser
Generic Procedure
• Now remove white target and check if the beam hits the
center of the laser head target on its shutter. If it doesn’t,
keep on adjusting the position of the machine until it hits
the target at the center.
• Now adjust reflector and splitter as close as possible and
align them together.
• Make sure that the faces are parallel with the one another
and with the machine axis.
61. Laser Interferomter
Setting up the laser
Generic Procedure
• Now use a target at the input aperture with white spot
at the top and translate machine axis vertically and
horizontally so that the beam hits the target.
• Now take away the target and check if the returned
beam from the interferometer hits the center of the
shutter. If it does not repeat the motion of the machine
until it does hit the center.
62. Laser Interferomter
Set up the measurements/optics
Introduction
• We have elaborated about the 21 measurements needed
for complete calibration of CMM.
• Majorly these measurements are divided into three
groups:
– Linearity
– Straightness
– Rotation and
– Squareness
• Now we will elaborate the different configurations of
the optics that are used to take these measurements
63. Laser Interferomter
Set up the measurements/optics
Linearity
• Linear measurements are made at multiple points
along a machine’s travel path to measure linear
displacement and velocity.
• It is checked to improve positioning accuracy along an
axis for any machine that requires positioning
accuracy and velocity control.
64. Laser Interferomter
Set up the measurements/optics
Optics required
• To make linear measurements following optics are
required:
– Beam Splitter
– Linear Reflectors
– Targets
– Height adjustment fixtures
Renishaw XL 80
Agilent 5529A
67. Laser Interferomter
Set up the measurements/optics
Straightness
• Straightness measurements evaluate the unwanted side
to-side or up-and-down motion of a machine tool’s
travel in a specified direction.
68. Laser Interferomter
Set up the measurements/optics
Optics required
• To make straightness measurements following optics
are required:
– Straightness reflector
– Straightness interferometer
– Targets
– Height adjustment fixtures
Renishaw XL 80
Agilent 5529A
72. Laser Interferomter
Set up the measurements/optics
Rotation
• Angular measurements are made at multiple points
along a machine’s travel path to test for rotation about
an axis perpendicular to the axis of motion (roll, pitch
and yaw)
• Unwanted angular motion in a machine tool causes
positioning errors that reduce the overall accuracy of
your machine.
73. Laser Interferomter
Set up the measurements/optics
Optics required
• To make straightness measurements following optics
are required:
– Angular reflector
– Angular interferometer
– Targets
– Height adjustment fixtures
Renishaw XL 80
Agilent 5529A
77. Laser Interferomter
Set up the measurements/optics
Squareness
• Angular measurements are made at multiple points
along a machine’s travel path to test for rotation about
an axis perpendicular to the axis of motion (roll, pitch
and yaw)
• Unwanted angular motion in a machine tool causes
positioning errors that reduce the overall accuracy of
your machine.
78. Laser Interferomter
Set up the measurements/optics
Optics required
• To make squareness measurements following optics
are required:
– Optical Square
– Brackets
– Targets
– Height adjustment fixtures
Renishaw XL 80
Agilent 5529A
81. Laser Interferomter
Collect the data and analyze according to
international standards
Parameters to be entered
• After the required measurement optics have been setup
and is ready to be measured. Usually the following
information is entered in the software to begin taking
measurements:
– Start position for the measurement
– End position (Length of the axis of your machine)
– Interval (It can be 10, 50, 100)
– No. of points
– No. of cycles (For bidirectional checks)
84. Laser Interferomter
Collect the data and analyze according to
international standards
Analyzing data
• After the readings have been taken the software shows
statistical chart that represents the points that are out of
tolerance.
• This graphical representation is according to the
standard you have chosen. You choose the standard
that your OEM has specified for the calibration of the
machine.
86. Laser Interferomter
Compensation of results
• After the data has been analyzed according to a
standard, software provides the compensation table for
the measurement you have taken.
• This information is then fed into the specific software
of the machine used for this purpose. E.g Geocomp is
used for compensation for Global Image CMM.
88. Laser Interferomter
Some post checks
Post Checks
• After all the measurements have been compensated,
machine is operated in dry run mode. That checks
healthy operation.
• E&R test elaborated before is also performed to check
that all the measurements of the machine are in the
tolerance defined by the macnufacturer
89. Calibration of CMMs
References
• Coordinate Measuring Machines and Systems by
Robert J. Hocken & Paulo H. Pereira
• Leitz 10360-2 guide
• NPL Guidelines – Good Practice Guide No. 42
• Agilent 5529A Manual
• Renishaw user guide for XL-80
• Wikipedia
Pictures taken from:
- Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
- http://blog.coghillcartooning.com/5367/great-pyramid-giza-cartoon-sketch/
Pictures taken from:
Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
http://upload.wikimedia.org/wikipedia/commons/b/bc/Coud%C3%A9e-turin.jpg
http://www.directindustry.com/prod/brown-sharpe/high-precision-coordinate-measuring-machine-cmm-7157-788233.html
Pictures taken from:
http://www.directindustry.com/prod/brown-sharpe/high-precision-coordinate-measuring-machine-cmm-7157-788233.html
Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
Pictures taken from:
http://www.directindustry.com/prod/brown-sharpe/high-precision-coordinate-measuring-machine-cmm-7157-788233.html
Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
Pictures taken from:
Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
Pictures taken from:
Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira
Pictures taken from:
http://www.sdm-measuring.it/wp-content/uploads/2013/05/SDM-21coor-.jpg
Pictures taken from:
- http://www.leedsmicro.com/blog/2015/02/09/iso-17025-how-accreditation-impacts-forensic-laboratories/
Pictures taken from:
iso.org
NPL guidelines
Picture taken from:
- Coordinate Measuring Machines and Systems by Robert J. Hocken & Paulo H. Pereira