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Articles About measurement error


1 Measurement Error Induced by Measuring over Pins Instead of Balls (January/February 1996)

The purpose of this article is to clarify some terms and methods used in measuring the size of gears. There is also an explanation given of the error induced and how to correct for it in certain cases when the measurement is made using pins instead of balls.

2 Calibration of Two-Flank Roll Testers (May 2008)

The presence of significant errors in the two-flank roll test (a work gear rolled in tight mesh against a master gear) is well-known, but generally overlooked.

3 Noise Reduction in Plastic & Powder Metal Gear Sets (July/August 1996)

The data discussed in this article was taken from an upright vacuum cleaner. This was a prototype cleaner that was self-propelled by a geared transmission. It was the first time that the manufacturer had used a geared transmission in this application.

4 Identification of Gear Noise with Single Flank Composite Measurement (May/June 1986)

Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.

5 Characteristics of Master Gears (November/December 2006)

The two-flank roll test measures kickout (tooth-to-tooth composite error) and tooth thickness. In this article, it will be shown that measured values vary with the number of teeth on the master gear.

6 Transmission Error and Noise Emission of Spur Gears (March/April 2007)

Transmission error (TE) is recognized as one of the most important causes of gear acoustic emissions...

7 Gear Inspection and Chart Interpretation (May/June 1985)

Much information has been written on gear inspection, analytical. functional. semiautomatic and automatic. In most cases, the charts, (if you are lucky enough to have recording equipment) have been explained.

8 Thermal Effects on CMMs (September/October 1997)

The trend toward moving coordinate measuring machines to the shop floor to become an integral part of the manufacturing operations brings real time process control within the reach of many companies. Putting measuring machines on the shop floor, however, subjects them to harsh environmental conditions. Like any measuring system, CMMs are sensitive to any ambient condition that deviates from the "perfect" conditions of the metrology lab.

9 Improving Gear Manufacturing Quality With Surface Texture Measurement (March/April 1993)

The working surfaces of gear teeth are often the result of several machining operations. The surface texture imparted by the manufacturing process affects many of the gear's functional characteristics. To ensure proper operation of the final assembly, a gear's surface texture characteristics, such as waviness and roughness, can be evaluated with modern metrology instruments.

10 Automated Inspection Systems: The Whole Picture (January/February 1998)

No one (not even you and I) consistently makes parts with perfect form and dimensions, so we must be able to efficiently check size and shape at many stages in the manufacturing and assembly process to eliminate scrap and rework and improve processes and profits. Automated inspection systems, which are widely used in all kinds of manufacturing operations, provide great efficiencies in checking individual features, but may not be as effective when asked to evaluate an entire part. You need to know why this is true and what you can do to improve your part yields.

11 Programmable Separation of Runout From Profile and Lead Inspection Data for Gear Teeth With Arbitrary Modifications (March/April 1998)

A programmable algorithm is developed to separate out the effect of eccentricity (radial runout) from elemental gear inspection date, namely, profile and lead data. This algorithm can be coded in gear inspection software to detect the existence, the magnitude and the orientation of the eccentricity without making a separate runout check. A real example shows this algorithm produces good results.

12 Measurement of Involute Master (January/February 2013)

Our experts tackle the topic of measuring involute masters, including both master gears and gear inspection artifacts.

13 CMM Gear Inspection (January/February 2013)

Mitutoyo offers capable, affordable and flexible gear inspection option via coordinate measuring machines and gear inspection software.

14 Worm Gear Measurement (September/October 1997)

Several articles have appeared in this publication in recent years dealing with the principles and ways in which the inspection of gears can be carried out, but these have dealt chiefly with spur, helical and bevel gearing, whereas worm gearing, while sharing certain common features, also requires an emphasis in certain areas that cause it to stand apart. For example, while worm gears transmit motion between nonparallel shafts, as do bevel and hypoid gears, they usually incorporate much higher ratios and are used in applications for which bevel would not be considered, including drives for rotary and indexing tables in machine tools, where close tolerance of positioning and backlash elimination are critical, and in situations where accuracy of pitch and profile are necessary for uniform transmission at speed, such as elevators, turbine governor drives and speed increasers, where worm gears can operate at up to 24,000 rpm.

15 M & M Precision, Penn State & NIST Team Up For Gear Metrology Research (July/August 1997)

In 1993, M & M Precision Systems was awarded a three-year, partial grant from the Advanced Technology Program of the Department of Commerce's National Institute of Standards and Technology (NIST). Working with Pennsylvania State University, M&M embarked on a technology development project to advance gear measurement capabilities to levels of accuracy never before achieved.

16 How to Avoid Errors When Measuring Step Gears (July/August 1995)

There are problems in dimensional measurement that should be simple to solve with standard measuring procedures, but aren't. In such cases, using accepted practices may result in errors of hundreds of microns without any warning that something is wrong.

17 Quality Gear Inspection - Part II (November/December 1994)

This section will deal with the use of gear inspection for diagnostic purposes rather than quality determination. The proper evaluation of various characteristics in the data can be useful for the solution of quality problems. It is important to sort out whether the problem is coming from the machine, tooling and/or cutters, blanks, etc. An article by Robert Moderow in the May/June 1985 issue of Gear Technology is very useful for this purpose.

18 Gear Inspection For The Long Haul (September/October 1995)

Question: We just received permission to purchase our first CNC gear inspection system. With capital approvals so hard to come by, especially for inspection equipment, I want to be sure to purchase a system I can count of for years to come. My past experience with purchasing CNC equipment has shown me that serviceability of the computer and the CNC controller portion of the system can be a problem in just a few years because of the obsolescence factor. What information do I need to look for when selecting a supplier to reduce the risk of obsolescence, as well as to reduce the long-term servicing costs in the computer and controls portion of the system?

19 Gear Standards and ISO GPS (October 2013)

In today’s globalized manufacturing, all industrial products having dimensional constraints must undergo conformity specifications assessments on a regular basis. Consequently, (standardization) associated with GD&T (geometrical dimensioning and tolerancing) should be un-ambiguous and based on common, accepted rules. Of course gears - and their mechanical assemblies - are special items, widely present in industrial applications where energy conversion and power transmission are involved.

20 Quality Gear Inspection - Part I (September/October 1994)

Quality gear inspection means doing the "right" inspections "right." A lot of time and money can be spent doing the wrong types of inspections related to function and doing them incorrectly. As we will discover later, such things as runout can creep into the manufacturing and inspection process and completely ruin any piece of data that is taken. this is one of the most important problems to control for quality inspection.

21 Gear Tip Chamfer and Gear Noise; Surface Measurement of Spiral Bevel Gear Teeth (July/August 1993)

Could the tip chamfer that manufacturing people usually use on the tips of gear teeth be the cause of vibration in the gear set? The set in question is spur, of 2.25 DP, with 20 degrees pressure angle. The pinion has 14 teeth and the mating gear, 63 teeth. The pinion turns at 535 rpm maximum. Could a chamfer a little over 1/64" cause a vibration problem?

22 Obtaining Meaningful Surface Roughness Measurements on Gear Teeth (July/August 1997)

Surface roughness measuring of gear teeth can be a very frustrating experience. Measuring results often do not correlate with any functional characteristic, and many users think that they need not bother measuring surface roughness, since the teeth are burnished in operation. They mistakenly believe that the roughness disappears in a short amount of time. This is a myth! The surface indeed is shiny, but it still has considerable roughness. In fact, tests indicate that burnishing only reduces the initial roughness by approximately 25%.

23 Tooth Flank Corrections of Wide Face Width Helical Gears that Account for Shaft Deflections (January/February 2005)

This paper discusses the influence of tip relief, root relief, load modification, end relief and their combinations on gear stresses and transmission errors due to shaft deflections.

24 Gear Noise and the Making of Silent Gears (March/April 1990)

Our research group has been engaged in the study of gear noise for some nine years and has succeeded in cutting the noise from an average level to some 81-83 dB to 76-78 dB by both experimental and theoretical research. Experimental research centered on the investigation into the relation between the gear error and noise. Theoretical research centered on the geometry and kinematics of the meshing process of gears with geometric error. A phenomenon called "out-of-bound meshing of gears" was discovered and mathematically proven, and an in-depth analysis of the change-over process from the meshing of one pair of teeth to the next is followed, which leads to the conclusion we are using to solve the gear noise problem. The authors also suggest some optimized profiles to ensure silent transmission, and a new definition of profile error is suggested.

25 The Uses and Limitations of Transmission Error (July/August 1988)

The concept of "transmission error" is relatively new and stems from research work in the late 1950s by Gregory, Harris and Munro,(1) together with the need to check the accuracy of gear cutting machines. The corresponding commercial "single flank" testing equipment became available in the 1960s, but it was not until about ten years ago that it became generally used, and only recently has it been possible to test reliably at full load and full speed.

26 The Relationship of Measured Gear Noise to Measured Gear Transmission Errors (January/February 1988)

Vehicle gear noise testing is a complex and often misunderstood subject. Gear noise is really a system problem.(1) most gearing used for power transmission is enclosed in a housing and, therefore, little or no audible sound is actually heard from the gear pair.(2) The vibrations created by the gears are amplified by resonances of structural elements. This amplification occurs when the speed of the gear set is such that the meshing frequency or a multiply of it is equal to a natural frequency of the system in which the gears are mounted.

27 Transmission Errors and Bearing Contact of Spur, Helical, and Spiral Bevel Gears (July/August 1990)

An investigation of transmission errors and bearing contact of spur, helical, and spiral bevel gears was performed. Modified tooth surfaces for these gears have been proposed in order to absorb linear transmission errors caused by gear misalignment and to localize the bearing contact. Numerical examples for spur, helical, and spiral bevel gears are presented to illustrate the behavior of the modified gear surfaces with respect to misalignment and errors of assembly. The numerical results indicate that the modified surfaces will perform with a low level of transmission error in non-ideal operating environments.

28 Designing Hardened & Ground Spur Gears to Operate With Minimum Noise (May/June 1994)

When designing hardened and ground spur gears to operate with minimum noise, what are the parameters to be considered? should tip and/or root relief be applied to both wheel and pinion or only to one member? When pinions are enlarged and he wheel reduced, should tip relief be applied? What are the effects on strength, wear and noise? For given ratios with enlarged pinions and reduced wheels, how can the gear set sized be checked or adjusted to ensure that the best combination has been achieved?

29 The Basics of Gear Metrology and Terminology Part I (September/October 1998)

It is very common for those working in the gear manufacturing industry to have only a limited understanding of the fundamental principals of involute helicoid gear metrology, the tendency being to leave the topic to specialists in the gear lab. It is well known that quiet, reliable gears can only be made using the information gleaned from proper gear metrology.

30 Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions (July/August 1994)

In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated, and the individual tooth load is overstated, especially for heavily loaded gears. This article compares the static transmission error and dynamic load of heavily loaded, low-contact-ratio spur gears when the effect of tooth flexibility has been considered and when it has been ignored. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.

31 Longitudinal Load Distribution Factor for Straddle- and Overhang-Mounted Spur Gears (July/August 1987)

A pair of spur gears generally has an effective lead error which is caused, not only by manufacturing and assembling errors, but also by the deformations of shafts, bearings and housings due to the transmitted load. The longitudinal load distribution on a contact line of the teeth of the gears is not uniform because of the effective lead error.

32 Viewpoint (May/June 1987)

Joe Arvin comments on his recent trip to Scandinavia and how U.S. defense dollars are being spent overseas. J.D. Smith responds to an article on gear noise from the previous issue.

33 To Err is Human. But Making a Habit of it Will Cost You (June 2008)

Everyone makes mistakes. Nobody's perfect. We've all heard those or similar words, and if you happen to be in charge of your company's quality efforts, you've probably heard them more than most people.

34 Reader Dialogue: Functional Measurement of Gears; More Good Gear Books (September/October 1992)

From time to time, the editors of "Shop Floor" receive correspondence from readers relating to particular articles they have written for past issues. As one of the purposes of this column is to provide a forum for the exchange of ideas, we reproduce here two of these letters and their replies. The subject of the first is the functional measurement of gears. (See Gear Technology, Sept/Oct, 1991, p. 17) Robert E. Smith writes the reply.

35 A Further Study on High-Contact-Ratio Spur Gears in Mesh with Double-Scope Tooth Profile Modification (November/December 2008)

This paper will demonstrate that, unlike commonly used low-contact-ratio spur gears, high-contact-ratio spur gears can provide higher power-to-weight ratio, and can also achieve smoother running with lower transmission error (TE) variations.

36 Effects of Profile Corrections on Peak-to-Peak Transmission Error (July 2010)

Profile corrections on gears are a commonly used method to reduce transmission error, contact shock, and scoring risk. There are different types of profile corrections. It is a known fact that the type of profile correction used will have a strong influence on the resulting transmission error. The degree of this influence may be determined by calculating tooth loading during mesh. The current method for this calculation is very complicated and time consuming; however, a new approach has been developed that could reduce the calculation time.

37 Optimizing Gear Geometry for Minimum Transmission Error, Mesh Friction Losses and Scuffing Risk Through Computer- Aided Engineering (August 2010)

Minimizing gear losses caused by churning, windage and mesh friction is important if plant operating costs and environmental impact are to be minimized. This paper concentrates on mesh friction losses and associated scuffing risk. It describes the preliminary results from using a validated, 3-D Finite Element Analysis (FEA) and Tooth Contact Analysis (TCA) program to optimize cylindrical gears for low friction losses without compromising transmission error (TE), noise and power density. Some case studies and generic procedures for minimizing losses are presented. Future development and further validation work is discussed.

38 Gear Noise and the Sideband Phenomenon (January/February 1987)

Gear noise can be a source of intense annoyance. It is often the primary source of annoyance even when it is not the loudest noise component. This is because of the way it is perceived. Gear noise is a collection of pure tones which the human ear can detect even when they are 10dB lower than the overall noise level. Another reason for our sensitivity to transmission noise is that we associate it with impending mechanical failure.

39 Evaluation of Methods for Calculating Effects of Tip Relief on Transmission Error, Noise and Stress in Loaded Spur Gears (January/February 2012)

The connection between transmission error, noise and vibration during operation has long been established. Calculation methods have been developed to describe the influence so that it is possible to evaluate the relative effect of applying a specific modification at the design stage. These calculations enable the designer to minimize the excitation from the gear pair engagement at a specific load. This paper explains the theory behind transmission error and the reasoning behind the method of applying the modifications through mapping surface profiles and determining load sharing.

40 How Are You Dealing with the Bias Error in Your Helical Gears (May 2009)

This paper initially defines bias error—the “twisted tooth phenomenon.” Using illustrations, we explain that bias error is a by-product of applying conventional, radial crowning methods to produced crowned leads on helical gears. The methods considered are gears that are finished, shaped, shaved, form and generated ground. The paper explains why bias error occurs in these methods and offers techniques used to limit/eliminate bias error. Sometimes, there may be a possibility to apply two methods to eliminate bias error. In those cases, the pros/cons of these methods will be reviewed.

41 Single Flank Measuring; Estimating Horsepower Capacity (September/October 1991)

Question: What is functional measurement and what is the best method for getting truthful answers?

42 User-Friendly Gear Measurement (July 2010)

Good timing leads to partnership between Process Equipment and Schafer Gear.

43 Large Gears, Better Inspection (July 2010)

Investment in Gleason GMM Series inspection equipment helps drive Milwaukee Gear's expansion into profitable new markets around the world—all hungry for high-precision custom gears and gear drives.

44 Improved Inspection Software Helps Provide Optimum Cutting Results (July 2010)

Klingelnberg measuring centers eliminate trial-and-error with modern analysis tools.

45 Cotta Transmission Installs CMM with Gear Checking Module (July 2010)

Xspect Solutions Provides Wenzel Bridge-Type CMM Equipped with OpenDMIS Software for Basic Gear Measuring Capability with CMM Flexibility.

46 Measurement of Directly Designed Gears with Symmetric and Asymmetric Teeth (January/February 2011)

In comparison with the traditional gear design approach based on preselected, typically standard generating rack parameters, the Direct Gear Design method provides certain advantages for custom high-performance gear drives that include: increased load capacity, efficiency and lifetime; reduced size, weight, noise, vibrations, cost, etc. However, manufacturing such directly designed gears requires not only custom tooling, but also customization of the gear measurement methodology. This paper presents definitions of main inspection dimensions and parameters for directly designed spur and helical, external and internal gears with symmetric and asymmetric teeth.

47 Zoller and Ingersoll Partner for Measuring Hob Cutters (March/April 2011)

With growing markets in aerospace and energy technologies, measuring hob cutters used in gear cutting is becoming an essential requirement for workpieces and machine tools. Zoller, a provider of solutions for tool pre-setters, measuring and inspection machines and tool management software, has developed a new partnership with Ingersoll/Germany for shop floor checking of hob cutters by a combined hardware and software approach.

48 Carl Zeiss CMM Guides Andrew Tool with Complex Mars Rover Project (March/April 2011)

At Andrew Tool, CMMs have been an integral part of their manufacturing processes for years, but they had never faced a project with such intricate measurements, tight tolerances, heat treatments and a very short time frame requirement.

49 Update on the National Center for Gear Metrology (May 2008)

The status on traceability of gear artifacts in the United States.

50 Measuring Pitch Diameter (September/October 2005)

Wait a minute, we don't measure pitch diameter. We're sometimes asked to measure it by customers, though, especially ones with older drawings.

51 Industry Forum (July/August 1985)

In response to Ed Uberts letter, we have come a long way in gearing since WWII. The Europeans do use long addendum pinions in many cases. This modification does improve load capacity, sliding conditions and the working life of a gearset. When modifying a pinion tooth it is necessary to modify the gear tooth or adjust the center distance accordingly but we will leave that to the designers.

52 Industry Forum (September/October 1985)

Your May/June issue contains a letter from Edward Ubert of Rockwell International with some serious questions about specifying and measuring tooth thickness.

53 Single Flank Data Analysis and Interpretation (September/October 1985)

Much of the information in this article has been extracted from an AGMA Technical Paper, "What Single Flank Testing Can Do For You", presented in 1984 by the author

54 Industry Forum (May/June 1985)

This letter is in response to your article asking the readers where their interests lie. The division of Rockwell International where I work has engineering departments in Cicero.

55 Involute Spline Size Inspection (March/April 1985)

This article describes a new technique for the size determination of external Involute splines by using a span measuring method. It provides application performance information demonstrating how this method and its measurements correlate with the traditional spline ring gage sizing method.

56 Extending the Benefits of Elemental Gear Inspection (July 2009)

It may not be widely recognized that most of the inspection data supplied by inspection equipment, following the practices of AGMA Standard 2015 and similar standards, are not of elemental accuracy deviations but of some form of composite deviations. This paper demonstrates the validity of this “composite” label by first defining the nature of a true elemental deviation and then, by referring to earlier literature, demonstrating how the common inspection practices for involute, lead (on helical gears), pitch, and, in some cases, total accumulated pitch, constitute composite measurements.

57 In-Situ Measurement of Stresses in Carburized Gears via Neutron Diffraction (May 2009)

This paper presents the results of research directed at measuring the total stress in a pair of statically loaded and carburized spur gears. Measurements were made to examine the change in total stress as a function of externally applied load and depth below the surface.

58 Gear Measuring Machine by NDG Method for Gears Ranging from Miniature to Super-Large (March/April 2011)

A new inspection method has several advantages over traditional methods, especially for very large or very small gears.

59 Dearborn Precision Puts Dual Purpose Zeiss CMM to the Task (May 2011)

When parts you manufacture pass through numerous processes such as deep hole drilling, machining, hobbing and grinding, a CMM is essential when your customers require 100 percent in-process and final inspection.

60 Runout, Helix Accuracy and Shaper Cutters (June/July 2012)

Our experts discuss runout and helix accuracy, as well as the maximum number of teeth in a shaper cutter.

61 Gear Quality Inspection: How Good is Yours (June/July 2012)

How well you conduct your inspections can be the difference-maker for securing high-value contracts from your customers. And as with most other segments of the gear industry, inspection continues striving to attain “exact science” status. With that thought in mind, following is a look at the state of gear inspection and what rigorous inspection practices deliver—quality.

62 Tomorrow's Gear Inspection Systems: Arriving Just in Time (June/July 2012)

Gleason's GMS analytical gear inspection systems provide all the right features at Eaton Corp.

63 Towards an Improved AGMA Accuracy Classification System on Double-Flank Composite Measurements (June/July 2012)

AGMA introduced ANSI/AGMA 2015–2–A06— Accuracy Classification System: Radial System for Cylindrical Gears, in 2006 as the first major rewrite of the double-flank accuracy standard in over 18 years. This document explains concerns related to the use of ANSI/AGMA 2015–2–A06 as an accuracy classification system and recommends a revised system that can be of more service to the gearing industry.

64 What Is Runout, And Why Should I Worry About It (January/February 1991)

Runout is a troublemaker! Good shop practice for the manufacture or inspection of gears requires the control of runout. Runout is a characteristic of gear quality that results in an effective center distance variation. As long as the runout doesn't cause loss of backlash, it won't hurt the function of the gear, which is to transmit smooth motion under load from one shaft to another. However, runout does result in accumulated pitch variation, and this causes non-uniform motion, which does affect the function of the gears. Runout is a radial phenomenon, while accumulated pitch variation is a tangential characteristic that causes transmission error. Gears function tangentially. It is also possible to have a gear with accumulated pitch variation, but little or no runout.

65 Effects of Temperature on Gage Repeatability & Reproducibility (May/June 1992)

Temperature Induced Dimensional Changes Temperature causes various materials to change size at different rate, known as their Coefficients of Expansion (COE). The effects of this phenomenon on precision dimensional measurements are continuous and costly to industry. Precautions can be taken to allow parts and gages to temperature stabilize before conducting gage R & R studies, but the fact remains that on the shop floor temperatures vary all the time. The slow pace at which industry has accepted this reality probably has to do with the subtlety of these tiny size variations and our inability to sense gradual, but significant temperature changes.

66 Recent Developments in Gear Metrology (November/December 1991)

Metrology is a vital component of gear manufacturing. Recent changes in this area, due in large part to the advent of computers, are highlighted in this article by comparison with more traditional methods.

67 Viewpoint (November/December 1988)

Eliot K. Buckingham explains the procedure for proper measurement over wires for worm gears, in response to last issue's article.

68 The Interrelationship of Tooth Thickness Measurements as Evaluated by Various Measuring Techniques (September/October 1987)

The first commandment for gears reads "Gears must have backlash!" When gear teeth are operated without adequate backlash, any of several problems may occur, some of which may lead to disaster. As the teeth try to force their way through mesh, excessive separating forces are created which may cause bearing failures. These same forces also produce a wedging action between the teeth with resulting high loads on the teeth. Such loads often lead to pitting and to other failures related to surface fatigue, and in some cases, bending failures.

69 Not All Good Ideas Are Brand New (September 2011)

A reader clarifies technology presented in the March/April 2011 issue.

70 An Emphasis on Accuracy (June/July 2011)

Meeting the many challenges of large gear inspection.

71 Single Flank Testing of Gears (May/June 1984)

Presumably, everyone who would be interested in this subject is already somewhat familiar with testing of gears by traditional means. Three types of gear inspection are in common use: 1) measurement of gear elements and relationships, 2) tooth contact pattern checks and 3) rolling composite checks. Single Flank testing falls into this last category, as does the more familiar Double Flank test.

72 Optimum Number of Teeth for Span Measurement (May/June 1984)

An expression is derived, giving the optimum number of teeth over which the span measurement should be made, for profile-shifted spur and helical gears.

73 Checking Large Gears (March/April 1987)

Gear manufacturing schedules that provide both quality and economy are dependent on efficient quality control techniques with reliable measuring equipment. Given the multitude of possible gear deviations, which can be found only by systematic and detailed measuring of the gear teeth, adequate quality control systems are needed. This is especially true for large gears, on which remachining or rejected workpieces create very high costs. First, observation of the gears allows adjustment of the settings on the equipment right at the beginning of the process and helps to avoid unproductive working cycles. Second, the knowledge of deviations produced on the workpiece helps disclose chance inadequacies on the production side: e.g., faults in the machines and tools used, and provides an opportunity to remedy them.

74 Generating and Checking Involute Gear Teeth (May/June 1986)

It has previously been demonstrated that one gear of an interchangeable series will rotate with another gear of the same series with proper tooth action. It is, therefore, evident that a tooth curve driven in unison with a mating blank, will "generate" in the latter the proper tooth curve to mesh with itself.

75 Gear Inspection and Measurement (July/August 1992)

The purpose of gear inspection is to: Assure required accuracy and quality, Lower overall cost of manufacture by controlling rejects and scrap, Control machines and machining practices and maintain produced accuracy as machines and tools wear, Determine hear treat distortions to make necessary corrections.