mark c. malburg surface metrology · dealing with the crown • issues: — the nominal profile is...
TRANSCRIPT
![Page 1: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/1.jpg)
1 Copyright 2001 - Digital Metrology Solutions, Inc.
Dimensional & Dimensional & Surface MetrologySurface Metrology
Mark C. Malburg
![Page 2: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/2.jpg)
2 Copyright 2001 - Digital Metrology Solutions, Inc.
Dimensional and Surface Dimensional and Surface MetrologyMetrology
•• Where We AreWhere We Are— Historical Overview— Information Overload — Instrument Overlaps
•• Customer Concerns Customer Concerns •• Where We Should be GoingWhere We Should be Going
— Understanding of Functionality— Underlying Standards Providing Tools— Uncertainty as a Connection to Reality
•• Case StudiesCase Studies•• RecommendationsRecommendations
![Page 3: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/3.jpg)
3 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We AreWhere We Are
A Brief Historical OverviewA Brief Historical Overview
![Page 4: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/4.jpg)
4 Copyright 2001 - Digital Metrology Solutions, Inc.
Historical Metrology ThinkingHistorical Metrology Thinking
•• The historical approach to “size”The historical approach to “size”
mm x10
12
34
56
70
80
60
![Page 5: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/5.jpg)
5 Copyright 2001 - Digital Metrology Solutions, Inc.
Modern Metrology ThinkingModern Metrology Thinking
•• Some modern approaches to “size”Some modern approaches to “size”
![Page 6: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/6.jpg)
6 Copyright 2001 - Digital Metrology Solutions, Inc.
Historical Metrology ThinkingHistorical Metrology Thinking
•• Historical Surface Roughness AssessmentHistorical Surface Roughness Assessment
![Page 7: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/7.jpg)
7 Copyright 2001 - Digital Metrology Solutions, Inc.
Modern Metrology ThinkingModern Metrology Thinking
•• Modern Surface Texture AnalysisModern Surface Texture Analysis
![Page 8: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/8.jpg)
8 Copyright 2001 - Digital Metrology Solutions, Inc.
Historical Developments and Historical Developments and the State of Metrologythe State of Metrology
•• Historically metrology instrumentation Historically metrology instrumentation provided a “number”provided a “number”— This “number” was often influenced by the
operator’s skill.•Alignment, scale-reading, force, etc.
•• Today’s metrology instrumentation is Today’s metrology instrumentation is capable of proving many “numbers”capable of proving many “numbers”— These “numbers” are often influenced by
several configurable parameters and controls.•Data density, filtering, algorithms, etc.
![Page 9: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/9.jpg)
9 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We AreWhere We Are
Information OverloadInformation Overload
![Page 10: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/10.jpg)
10 Copyright 2001 - Digital Metrology Solutions, Inc.
Information OverloadInformation Overload
•• Today’s metrology instrumentation is Today’s metrology instrumentation is providing more and more analytical providing more and more analytical capabilities.capabilities.— See also:
Whitehouse D.J., 1982, The Parameter Rash - Is There a Cure?”, Wear, 83, 75
![Page 11: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/11.jpg)
11 Copyright 2001 - Digital Metrology Solutions, Inc.
Increased Data Processing in a Increased Data Processing in a Simple ContextSimple Context
Taylor Hobson Form Talysurf SeriesTaylor Hobson Form Talysurf SeriesDOS Software rev 6.0DOS Software rev 6.0
— 71 Parameters— 3 Filter Types— 9 Roughness Cutoffs— Up to 3 Bandwidths at each cutoff
And this is for a “simple” stylus instrument!And this is for a “simple” stylus instrument!
![Page 12: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/12.jpg)
12 Copyright 2001 - Digital Metrology Solutions, Inc.
Information OverloadInformation Overload
•• These additional capabilities are not These additional capabilities are not necessarily a “bad” thing.necessarily a “bad” thing.— However, this introduces a new culture
requiring additional training and interpretation.
![Page 13: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/13.jpg)
13 Copyright 2001 - Digital Metrology Solutions, Inc.
Information OverloadInformation Overload
“The phenomenon of information overload is “The phenomenon of information overload is in its infancy. If according to some in its infancy. If according to some estimates, the amount of information estimates, the amount of information doubles every eighteen months, then by doubles every eighteen months, then by 2015 there will be 1,000 bits of data for 2015 there will be 1,000 bits of data for every fact in existence.every fact in existence.
![Page 14: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/14.jpg)
14 Copyright 2001 - Digital Metrology Solutions, Inc.
Information OverloadInformation Overload
“But we will not necessarily be better “But we will not necessarily be better informed. Meaningful facts informed. Meaningful facts —— those that those that have reliable and relevant information have reliable and relevant information —— will will become our most valuable resource.”become our most valuable resource.”
- Richard Worzel
Flying with Fast Company
American Way — February 1, 2000
![Page 15: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/15.jpg)
15 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We AreWhere We Are
The Overlap of InstrumentationThe Overlap of Instrumentation
![Page 16: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/16.jpg)
16 Copyright 2001 - Digital Metrology Solutions, Inc.
The Evolution of MeasurementThe Evolution of Measurement((in one really busy slidein one really busy slide))
Micro-burrs &Torn Material
Roughness Straightness Dimension(Size & Position)
Microscopy(Visual Assessment)
Sharp-Stylus(Roughness)Instruments
Special PurposeInstruments
Surface Plate(layout) Instruments& Gauges
λ
Micro-burrs &Torn Material
Roughness Straightness Dimension(Size & Position)
Microscopy(Visual & DigitalAssessment)
Stylus & Optical(Roughness)Instruments
Waviness
Roundness &CylindricityInstruments
CoordinateMeasuringMachines(CMM's)
λSurface Plate(layout) Instruments& Gauges
![Page 17: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/17.jpg)
17 Copyright 2001 - Digital Metrology Solutions, Inc.
Instrument OverlapsInstrument Overlaps
•• StraightnessStraightness
0.010
![Page 18: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/18.jpg)
18 Copyright 2001 - Digital Metrology Solutions, Inc.
Instrument OverlapsInstrument Overlaps
•• Who is right?Who is right?
0.010
![Page 19: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/19.jpg)
19 Copyright 2001 - Digital Metrology Solutions, Inc.
Instrument OverlapsInstrument Overlaps10
1
100
10
1
100
10
1
0.1
0.010.1 1 10 100 1 10 100 1 10 100 1000
mm
µmnm
nm µm mm
Am
plitu
de
Wavelength
STM
Talystep
Form Talysurf(Mark I)
Quality Today, April 1990
![Page 20: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/20.jpg)
20 Copyright 2001 - Digital Metrology Solutions, Inc.
Instrument OverlapsInstrument Overlaps
•• The overlap in surface metrology The overlap in surface metrology instrumentation produces problems as well instrumentation produces problems as well as opportunities.as opportunities.
![Page 21: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/21.jpg)
21 Copyright 2001 - Digital Metrology Solutions, Inc.
Instrument OverlapsInstrument Overlaps
CostsCosts
• Increased time spent dealing with correlation.
• Customer/Supplier Disputes
BenefitsBenefits
• Allows for a broader selection of instruments.
• Provides for competition between technologies.
• Provides a means for comparison.
![Page 22: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/22.jpg)
22 Copyright 2001 - Digital Metrology Solutions, Inc.
Customer ConcernsCustomer Concerns
Why does this stuff matter, anyway?Why does this stuff matter, anyway?
![Page 23: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/23.jpg)
23 Copyright 2001 - Digital Metrology Solutions, Inc.
What has value?What has value?
•• Numerical results that relate to the Numerical results that relate to the performanceperformance of a component.of a component.— Product functionality
•• Numerical results that relate to Numerical results that relate to processprocesscontrols.controls.— Process control
•• Numerical results that are Numerical results that are reproduciblereproducible..— Commerce enabling
![Page 24: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/24.jpg)
24 Copyright 2001 - Digital Metrology Solutions, Inc.
The Value of MeasurementThe Value of Measurement
Customers don’t generally want better Customers don’t generally want better metrology for the sake of metrology…metrology for the sake of metrology…
…customers want better information in …customers want better information in order to make their products better.order to make their products better.
Metrology is a means to an end.Metrology is a means to an end.
![Page 25: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/25.jpg)
25 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We Should be GoingWhere We Should be Going
An understanding of functionalityAn understanding of functionality
![Page 26: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/26.jpg)
26 Copyright 2001 - Digital Metrology Solutions, Inc.
FunctionalityFunctionality
“A picture may be worth a thousand words, “A picture may be worth a thousand words, but I’m an engineer, not a poet but I’m an engineer, not a poet —— give me a give me a number.”number.”
-- Chris BrownChris Brown
ASME B46 Subcommittee ASME B46 Subcommittee
on Fractal Analysis of Surface Textureon Fractal Analysis of Surface Texture
![Page 27: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/27.jpg)
27 Copyright 2001 - Digital Metrology Solutions, Inc.
Does this help functionality?Does this help functionality?
![Page 28: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/28.jpg)
28 Copyright 2001 - Digital Metrology Solutions, Inc.
Tolerance ReductionsTolerance Reductions
•• In many cases, reducing of tolerances is In many cases, reducing of tolerances is necessary in order to enhance or ensure necessary in order to enhance or ensure performance levels.performance levels.
•• However, there are many cases where However, there are many cases where tolerance reductions may not be the ideal tolerance reductions may not be the ideal approach.approach.
First Principle in Tolerance Reduction:First Principle in Tolerance Reduction:
Be sure that you are measuring the right thing!Be sure that you are measuring the right thing!
![Page 29: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/29.jpg)
29 Copyright 2001 - Digital Metrology Solutions, Inc.
Tolerance ReductionTolerance Reduction
•• A major automotive manufacturer was A major automotive manufacturer was dealing with camshaft failures.dealing with camshaft failures.— All dimensional attributes met the specifications.
— Roughness values met the specifications.
•• As the first step to improvement, the As the first step to improvement, the roughness tolerance was lowered.roughness tolerance was lowered.— The failure rate increased.
![Page 30: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/30.jpg)
30 Copyright 2001 - Digital Metrology Solutions, Inc.
Tolerance ReductionTolerance Reduction
•• Given these results, it was decided to Given these results, it was decided to further reduce the roughness in an effort to further reduce the roughness in an effort to get “past the sensitive area”.get “past the sensitive area”.— Failure rates increased further.
•• Additional analysis determined that the Additional analysis determined that the cause of failure was an underlying waviness.cause of failure was an underlying waviness.— Reduction in roughness exposed more of the
damaging effects of waviness.
![Page 31: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/31.jpg)
31 Copyright 2001 - Digital Metrology Solutions, Inc.
Tolerance ReductionTolerance Reduction
•• Be careful what you wish for. Making things Be careful what you wish for. Making things smoother may not make them better!smoother may not make them better!
Localized Contact Areas
![Page 32: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/32.jpg)
32 Copyright 2001 - Digital Metrology Solutions, Inc.
Two Approaches to Establishing Two Approaches to Establishing Functional CorrelationFunctional Correlation
•• “Mathematical”“Mathematical” CorrelationCorrelation—— Correlating a parameter or set of parameters Correlating a parameter or set of parameters
to a functionality via statistical methods.to a functionality via statistical methods.
•• “Physical”“Physical” CorrelationCorrelation—— Developing a model of functionality and a Developing a model of functionality and a
description of this functionality in terms of description of this functionality in terms of measured parameters.measured parameters.
![Page 33: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/33.jpg)
33 Copyright 2001 - Digital Metrology Solutions, Inc.
Two Approaches to Establishing Two Approaches to Establishing Functional CorrelationFunctional Correlation
•• Example: Plateau HoningExample: Plateau Honing
![Page 34: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/34.jpg)
34 Copyright 2001 - Digital Metrology Solutions, Inc.
Mathematical CorrelationMathematical Correlation
•• Plateau Honing Plateau Honing —— A set of parameters where evaluated in the A set of parameters where evaluated in the
comparison of “good” components to “bad” comparison of “good” components to “bad” components.components.
—— A mathematical relationship was developed A mathematical relationship was developed based on tolerance limits for 5 different based on tolerance limits for 5 different parameters and 2 ratios of the these parameters and 2 ratios of the these parameters.parameters.
![Page 35: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/35.jpg)
35 Copyright 2001 - Digital Metrology Solutions, Inc.
Physical CorrelationPhysical Correlation
•• Plateau HoningPlateau Honing—— The underlying functionalities were explored:The underlying functionalities were explored:
•Smooth running surface.•Deep grooves for oil retention/debris collection.•Controlled contact area.
—— The underlying process controls were The underlying process controls were explored:explored:•Rough honing•Fine honing•Placement of the fine honing within the base
texture.
![Page 36: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/36.jpg)
36 Copyright 2001 - Digital Metrology Solutions, Inc.
Physical CorrelationPhysical Correlation
•• Model of Plateau HoningModel of Plateau Honing— The combination of two random processes.
Valley-making Process
Plateau Process
Combination of Processes
![Page 37: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/37.jpg)
37 Copyright 2001 - Digital Metrology Solutions, Inc.
Physical CorrelationPhysical Correlation
•• Application of mathematics to the model.Application of mathematics to the model.— Normal probability analysis.
![Page 38: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/38.jpg)
38 Copyright 2001 - Digital Metrology Solutions, Inc.
Physical CorrelationPhysical Correlation
•• Development of parameters for the model.Development of parameters for the model.
RpqRpq: : Plateau RMS RoughnessPlateau RMS Roughness
RvqRvq:: Valley RMS RoughnessValley RMS Roughness
RmqRmq:: Material Ratio at Plateau to Valley TransitionMaterial Ratio at Plateau to Valley Transition
![Page 39: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/39.jpg)
39 Copyright 2001 - Digital Metrology Solutions, Inc.
Functional CorrelationFunctional Correlation
•• Sometimes Sometimes “mathematical”“mathematical” correlation is the correlation is the only available option in developing a only available option in developing a specification.specification.— No underlying mechanism can be established.— This can cause significant problems in the
development of manufacturing processes.
•• ““PhysicalPhysical” correlation is preferred.” correlation is preferred.— However, the underlying model is often very
difficult to generate.
![Page 40: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/40.jpg)
40 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We Should be GoingWhere We Should be Going
National and International Standards National and International Standards providing “Toolboxes”providing “Toolboxes”
![Page 41: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/41.jpg)
41 Copyright 2001 - Digital Metrology Solutions, Inc.
National & International National & International Surface Texture StandardsSurface Texture Standards
•• There is a difference in philosophy between There is a difference in philosophy between international (ISO) and national (ASME) international (ISO) and national (ASME) standards regarding surface texture:standards regarding surface texture:—— American Standards tend to attempt to American Standards tend to attempt to
describe common practice.describe common practice.
—— International Standards tend to attempt to International Standards tend to attempt to define an arbitrator method.define an arbitrator method.
![Page 42: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/42.jpg)
42 Copyright 2001 - Digital Metrology Solutions, Inc.
Standards Reflecting PracticeStandards Reflecting Practice
AdvantagesAdvantages
•• Provides a description Provides a description of many new and of many new and historical methods.historical methods.
•• Tend to be more Tend to be more tutorial in nature.tutorial in nature.
•• Recognizes other Recognizes other methods.methods.
DisadvantagesDisadvantages
•• Very difficult to Very difficult to ascertain the ascertain the “correct” “correct” measurement measurement method.method.
•• Difficult to apply in Difficult to apply in arbitration.arbitration.
![Page 43: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/43.jpg)
43 Copyright 2001 - Digital Metrology Solutions, Inc.
Standards Defining an Standards Defining an ArbitratorArbitrator
AdvantagesAdvantages
•• Provides a clear Provides a clear description of the description of the “correct” method.“correct” method.
•• Useful in disputes or Useful in disputes or arbitration.arbitration.
•• A “safety net” A “safety net” —— Unless otherwise Unless otherwise
specified.specified.
DisadvantagesDisadvantages
•• Not generally as Not generally as tutorial in nature.tutorial in nature.
•• Older instrumentation Older instrumentation tends to be ignored.tends to be ignored.
![Page 44: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/44.jpg)
44 Copyright 2001 - Digital Metrology Solutions, Inc.
How Full is the Toolbox?How Full is the Toolbox?
ISO/TC 213 Geometrical Product Specification (GPS)ISO/TC 213 Geometrical Product Specification (GPS)—— Chains of StandardsChains of Standards
![Page 45: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/45.jpg)
45 Copyright 2001 - Digital Metrology Solutions, Inc.
Chains of StandardsChains of Standards
•• These “chain links” define the arbitrator for These “chain links” define the arbitrator for specification and measurement.specification and measurement.—— Typically they define a single approach with the Typically they define a single approach with the
clause: clause:
“Unless otherwise specified…”“Unless otherwise specified…”
NOTE: This default approach may not be the NOTE: This default approach may not be the best approach for all applications!best approach for all applications!
![Page 46: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/46.jpg)
46 Copyright 2001 - Digital Metrology Solutions, Inc.
Good News!Good News!
•• Surface metrology standardization efforts Surface metrology standardization efforts are beginning to provide alternative are beginning to provide alternative methods for measurement and analysis.methods for measurement and analysis.—— Filtering and Extraction MethodsFiltering and Extraction Methods
—— Parameters and Analysis ApproachesParameters and Analysis Approaches
![Page 47: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/47.jpg)
47 Copyright 2001 - Digital Metrology Solutions, Inc.
Filtering and Extraction Filtering and Extraction MethodsMethods
•• Convolution FiltersConvolution Filters
Weighted, Moving Average
Waviness ProfileRaw Data
![Page 48: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/48.jpg)
48 Copyright 2001 - Digital Metrology Solutions, Inc.
Filtering and Extraction Filtering and Extraction MethodsMethods
•• Morphological FiltersMorphological Filters—— Based on various “structuring elements”.Based on various “structuring elements”.
![Page 49: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/49.jpg)
49 Copyright 2001 - Digital Metrology Solutions, Inc.
Filtering and Extraction Filtering and Extraction MethodsMethods
•• SplineSpline--based filtersbased filters
![Page 50: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/50.jpg)
50 Copyright 2001 - Digital Metrology Solutions, Inc.
Filtering and Extraction Filtering and Extraction MethodsMethods
•• Wavelets and Alternating Sequence FiltersWavelets and Alternating Sequence Filters—— MultiMulti--resolution analysisresolution analysis
![Page 51: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/51.jpg)
51 Copyright 2001 - Digital Metrology Solutions, Inc.
Filtering and Extraction Filtering and Extraction MethodsMethods
•• Robust FiltersRobust Filters—— Spline and Regression basedSpline and Regression based
![Page 52: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/52.jpg)
52 Copyright 2001 - Digital Metrology Solutions, Inc.
Parameters and Analysis Parameters and Analysis ApproachesApproaches
•• Evaluation of Surface Texture Using Fractal Evaluation of Surface Texture Using Fractal GeometryGeometry
![Page 53: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/53.jpg)
53 Copyright 2001 - Digital Metrology Solutions, Inc.
One Size Fits All.. One Size Fits All.. (not necessarily)(not necessarily)
•• These and future “tools” are providing These and future “tools” are providing users with many of techniques which can be users with many of techniques which can be applied to address a specific measurement applied to address a specific measurement of functionality issue.of functionality issue.— Various combinations of filtering and
parameterization can be developed to address specific needs.
![Page 54: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/54.jpg)
54 Copyright 2001 - Digital Metrology Solutions, Inc.
Where We Should be GoingWhere We Should be Going
Uncertainty as a Connection to RealityUncertainty as a Connection to Reality
![Page 55: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/55.jpg)
55 Copyright 2001 - Digital Metrology Solutions, Inc.
Measurement UncertaintyMeasurement Uncertainty
•• Dealing with Measurement Uncertainty is a Dealing with Measurement Uncertainty is a tremendous hurdle for many metrology users.tremendous hurdle for many metrology users.
•• Measurement Measurement Uncertainty doesn’t Uncertainty doesn’t necessarily mean that you necessarily mean that you are wrong. are wrong. —— It means that you are It means that you are
smart enough to know smart enough to know your limits!!!your limits!!!
![Page 56: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/56.jpg)
56 Copyright 2001 - Digital Metrology Solutions, Inc.
Measurement UncertaintyMeasurement Uncertainty
•• Uncertainty analysis can be a very beneficial Uncertainty analysis can be a very beneficial exercise.exercise.—— Helps to further refine the definition of the Helps to further refine the definition of the
“measurand”.“measurand”.—— Developing an understanding of significant Developing an understanding of significant
instrument variables.instrument variables.—— Establishing correlation limits between Establishing correlation limits between
instrumentation methods.instrumentation methods.—— Determining the “effective tolerance zone” and Determining the “effective tolerance zone” and
potential instrument influences.potential instrument influences.
![Page 57: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/57.jpg)
57 Copyright 2001 - Digital Metrology Solutions, Inc.
Case StudiesCase Studies
Working in the overlap between Working in the overlap between dimensional and surface metrologydimensional and surface metrology
![Page 58: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/58.jpg)
58 Copyright 2001 - Digital Metrology Solutions, Inc.
Working in the overlap…Working in the overlap…
•• Scale is irrelevantScale is irrelevant—— For example: step heights occur in inches as For example: step heights occur in inches as
well as angstroms.well as angstroms.
![Page 59: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/59.jpg)
59 Copyright 2001 - Digital Metrology Solutions, Inc.
Working in the overlap…Working in the overlap…
•• Extraction is essentialExtraction is essential
Initial LeastSquares Fit
Suppressionof Geometry
Outlier Removaland Filtering
Re-applicationof Geometry
Analysis of the Feature
![Page 60: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/60.jpg)
60 Copyright 2001 - Digital Metrology Solutions, Inc.
Working in the overlap…Working in the overlap…
•• Size and shape and wavelength content can Size and shape and wavelength content can be interrelatedbe interrelated
![Page 61: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/61.jpg)
61 Copyright 2001 - Digital Metrology Solutions, Inc.
Case Study #1Case Study #1A “Simple” CornerA “Simple” Corner
•• A certain corner should be “sharp” and “smooth” A certain corner should be “sharp” and “smooth” in a sealing application.in a sealing application.—— Limits were established for maximum blend radius and Limits were established for maximum blend radius and
maximum roughness.maximum roughness.
—— Tolerances were such that a stylus based profiling Tolerances were such that a stylus based profiling instrument was required.instrument was required.
r
![Page 62: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/62.jpg)
62 Copyright 2001 - Digital Metrology Solutions, Inc.
The CornerThe Corner
•• Issues:Issues:—— The measurement of a calculated radius is not The measurement of a calculated radius is not
reliablereliable•Very small arc segment•Local flats cause infinite radius
—— A zoneA zone--based approach is difficult.based approach is difficult.•Tolerance zone is not constant•Tolerance goes to zero at tangencies
—— Roughness around a corner Roughness around a corner is not well definedis not well defined r
![Page 63: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/63.jpg)
63 Copyright 2001 - Digital Metrology Solutions, Inc.
Dealing With the CornerDealing With the Corner
•• The angle was determined based on The angle was determined based on least least squares fittingsquares fitting of two lines.of two lines.
•• Based on the intersection, a Based on the intersection, a mathematical mathematical zonezone was established based on the was established based on the maximum allowed blend radius.maximum allowed blend radius.— This zone was bounded to avoid tangencies.— A “percentage consumed” value was reported.
• The corner was “unrolled” based on a convex hull to arrive at a roughness profile.
![Page 64: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/64.jpg)
64 Copyright 2001 - Digital Metrology Solutions, Inc.
Dealing with the CornerDealing with the Corner
![Page 65: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/65.jpg)
65 Copyright 2001 - Digital Metrology Solutions, Inc.
Case Study #2Case Study #2A “Complex” CrownA “Complex” Crown
•• A roller geometry is designed such that the A roller geometry is designed such that the pressure distribution is relatively uniform with no pressure distribution is relatively uniform with no significant edge loading.significant edge loading.—— The geometry is such that the edges are “rolledThe geometry is such that the edges are “rolled--off” off”
based on a lookup table.based on a lookup table.
—— The tolerance zone increases near the edges.The tolerance zone increases near the edges.
—— The overall length of the roller has a relatively loose The overall length of the roller has a relatively loose tolerance.tolerance.
—— Local concavities cannot be present.Local concavities cannot be present.
![Page 66: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/66.jpg)
66 Copyright 2001 - Digital Metrology Solutions, Inc.
Dealing with the CrownDealing with the Crown
•• Issues:Issues:—— The nominal profile is based on a lookThe nominal profile is based on a look--up table.up table.
•This table is based on finite element analysis of the contact pattern.
—— The lookThe look--up table position moves axially based up table position moves axially based on the roller width.on the roller width.•The roller width can “dilate” and “contract”.
—— Local concavities are not readily exploited by Local concavities are not readily exploited by standard parameters.standard parameters.
—— A nonA non--uniform tolerance zoneuniform tolerance zone•Small deviations near the edges can be tolerated,
while similar deviations near the center cannot.
![Page 67: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/67.jpg)
67 Copyright 2001 - Digital Metrology Solutions, Inc.
Dealing with the CrownDealing with the Crown
•• A A longlong--pass Gaussian filterpass Gaussian filter was applied to the data was applied to the data to reduce roughness effects in the profile analysis.to reduce roughness effects in the profile analysis.
•• A A 44--dimensional least squares fitdimensional least squares fit was applied to was applied to compare the measured profile to the nominal compare the measured profile to the nominal (dilated or contracted) geometry.(dilated or contracted) geometry.
•• A A convex hullconvex hull was applied to exploit local was applied to exploit local concavities.concavities.
•• A A “percentage consumed” approach“percentage consumed” approach was was developed to accommodate the variable tolerance developed to accommodate the variable tolerance widths along the profile.widths along the profile.
![Page 68: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/68.jpg)
68 Copyright 2001 - Digital Metrology Solutions, Inc.
Dealing with the CrownDealing with the Crown
![Page 69: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/69.jpg)
69 Copyright 2001 - Digital Metrology Solutions, Inc.
Where do we go from here?Where do we go from here?
A few ideas…A few ideas…
![Page 70: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/70.jpg)
70 Copyright 2001 - Digital Metrology Solutions, Inc.
RecommendationsRecommendations
•• Continue to develop “customizable” Continue to develop “customizable” metrology technology as the analytical tools metrology technology as the analytical tools are going to continue to evolve.are going to continue to evolve.— Recognize the distinction between
“data acquisition” and “data analysis”
•• Continue to “grow” the toolboxContinue to “grow” the toolbox— Through the sharing and standardizing of
methods
![Page 71: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/71.jpg)
71 Copyright 2001 - Digital Metrology Solutions, Inc.
RecommendationsRecommendations
•• Train, Educate, Teach, Instruct, Mentor, Train, Educate, Teach, Instruct, Mentor, Tutor, Coach, School, Inform, GuideTutor, Coach, School, Inform, Guide— Today’s engineering community is becoming
more aware of metrology, but very few understand metrology.
— Metrology doesn’t sell and apply itself. It requires educated customers.
![Page 72: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/72.jpg)
72 Copyright 2001 - Digital Metrology Solutions, Inc.
RecommendationsRecommendations
•• Strive to provide “information” rather than Strive to provide “information” rather than just “data”.just “data”.— Consider the questions behind the
measurement:•Is this part in tolerance?
•How well with this part perform?
•What do I need to change in the process?
![Page 73: Mark C. Malburg Surface Metrology · Dealing with the Crown • Issues: — The nominal profile is based on a look-up table. —-— —-](https://reader034.vdocument.in/reader034/viewer/2022042217/5ec106e2d7f01f2cb030e611/html5/thumbnails/73.jpg)
73 Copyright 2001 - Digital Metrology Solutions, Inc.
RecommendationsRecommendations
•• Continue to emphasize the importance of Continue to emphasize the importance of measurement uncertaintymeasurement uncertainty— This may be difficult at first, but significant
benefits can be achieved.
•• Continue to interact (openly) in forums such Continue to interact (openly) in forums such as this!as this!— Recognizing a balance between competition
and collaboration.