This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
This Website Uses Cookies
By closing this message or continuing to use our site, you agree to our cookie policy. Learn More
This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
Subscribe
  • Sign In
  • Create Account
  • Sign Out
  • My Account
  • Home
  • The Magazine
    • Current Issue
    • Digital Edition
    • Archives
    • How To Guide
    • Industry News
    • Subscribe
  • Web Exclusives
    • Apps
    • Blogs
    • NDT Exclusives
    • Quality Exclusives
    • Vision & Sensors
  • New Products
  • Channels
    • Management
    • Measurement
    • NDT
    • Quality 101
    • Software
    • Test & Inspection
    • Vision & Sensors
  • Markets
    • Aerospace
    • Automotive
    • Electronics
    • Energy
    • Green Manufacturing
    • Medical
    • Plastics
  • More
    • Leadership 100 Survey
    • Plant of the Year
    • Professional of the Year
    • Job Board
    • White Papers
    • Quality Store
    • Software Downloads
    • eCards
    • Product Spotlights
    • Industry Links
    • Featured Products
    • Sponsor Insights
    • Market Research
  • Multimedia
    • eNewsletter
    • Podcasts
    • Videos
    • Webinars
    • Showcases
    • Image Galleries
    • Interactive Spotlights
  • Events
    • IMTS
    • Event Calendar
    • Quality Show
  • InfoCenters
    • Improving Manufacturing Quality
    • Manage Quality, Risk & Compliance
    • Materials Testing & Analysis
    • Modern Quality Control with SPC
  • Directories
    • Buyers Guide
    • NDT Sourcebook
    • V&S Sourcebook
    • Take a Tour
  • Contact
    • Contact Us
    • Advertise
Home » Accurate and Repeatable Measurement
Measurement

Accurate and Repeatable Measurement

Using a rotary table on a CMM will improve process efficiency and productivity by reducing setup and process times.

Using a rotary table on a CMM

Using a rotary table on a CMM will improve process efficiency and productivity by reducing set up and process times. Source: RPI

Rotary tables increase a CMM’s available measuring volume. Source: RPI

Rotary tables increase a CMM’s available measuring volume. Source: RPI

A rotary table will significantly improve overall measurement accuracy of a CMM. Source: RPI

A rotary table will significantly improve overall measurement accuracy of a CMM. Source: RPI

Using a rotary table on a CMM
Rotary tables increase a CMM’s available measuring volume. Source: RPI
A rotary table will significantly improve overall measurement accuracy of a CMM. Source: RPI
October 24, 2017
Peter Marchbank
KEYWORDS CMMs / coordinate measurement machine (CMM) / Gage R&R
Reprints
No Comments

Accuracy and repeatability is the lifeblood of all CMMs. If they aren’t accurate, there’s no point in having them. However, the degree of accuracy required is dependent on the particular application. For manufacturing gas turbines and aircraft engines, a very high degree of accuracy is often required.

Now imagine that you want to walk in a perfectly straight line for a half-mile. And imagine that at the end of that walk, you find that you are ±2.5mm (one tenth of an inch) out. You’d be pretty pleased. In the world of golf, you’d also be pretty pleased if you scored a hole in one every time you teed off to a green 14 miles away!

Well, that level of accuracy can be achieved with high precision rotary tables. These can deliver precision geometry with axial performance well below 0.0005mm and positional accuracies to ±0.5 arc-seconds (±0.00014°).

Using a rotary table on a CMM will improve process efficiency and productivity by reducing setup and process times. A rotary table will also greatly increase a CMM’s available measuring volume thereby providing greater flexibility in what can be measured. And last but by no means least, a rotary table will also significantly improve overall measurement accuracy of a CMM, thereby reducing uncertainty.

Rotary tables enable very precise measurement of many geometrical characteristics, including angle, roundness, concentricity, parallelism, flatness and runout. They are used with: probes such as plunger, transducer and capacitance; optical such as autocollimator and laser interferometer; and electrical: oscilloscope and voltmeter.

Rotary tables enable accurate measurement of symmetrical/prismatic components such as rotor discs. In the measurement of a rotor disc, a CMM without a rotary table would require a machine with a large measuring volume. However, deploying a rotary table will reduce this volume significantly. This is because the volume of the CMM is directly related to the diameter of the disc as voluminous styli systems are usually required to measure a workpiece from all sides. This means a large proportion of its measuring range is required just to ensure collision free movement of the stylus around the part.

However, the introduction of the rotary table removes this requirement as the rotor can be presented directly to the stylus removing the requirement to access all sides. This in turn simplifies the stylus system allowing the measurement of larger workpieces in relation to the available measuring range, saving aerospace manufacturers both time and money.

As well as significantly improving overall measurement accuracy and reducing uncertainty in CMMs, rotary tables also greatly increase a CMM’s available measuring volume thereby providing greater flexibility in what can be measured.

Some tables have been specifically designed as a fourth axis for any high precision CMM to simplify measurement procedures, increase application range and measuring volume of symmetrical or prismatic components, including scanning applications. This is particularly important for large turbine disks for gas turbines or for airplanes. However, they are also starting to gain traction for smaller, lower measurement volume applications typical in the automotive industry.

For larger applications, some circular geometry inspection and assembly system can reduce inspection times by 90% and improve gage R&Rs by up to 10 times.

Air bearing spin tables are becoming more popular and rely on air lubricated hydrostatic bearings which provide very high radial and axial stiffness. This type of bearing offers significant advantages over conventional rolling element bearings permitting operation with minimal drag, vibration and mechanical noise.

The design of these bearings ensures axial laminar flow between shaft and housing compared with conventional orifice entry arrangements thereby ensuring exceptionally good motion geometry of less than 0.0001mm for axial and radial runout.

These tables can be combined with direct drive motors and high accuracy angular encoders. The encoder couples directly to the motor control system, which has its own high-resolution interpolator ensuring precise positioning and repeatability.

It is possible to fit a table with a high accuracy Hirth Coupling, which provides location and angular positioning of the tabletop. This delivers fast, accurate indexing between pre-set positions.

Rotary tables are so accurate that they can be forgotten, when using a CMM. And that’s no bad thing for manufacturers who need precision time and time again. 

subscribe to Quality Magazine

Peter Marchbank is the managing director of RPI (www.rpiuk.com). RPI distributes its rotary tables in the U.S. through Wyvern Industrial Technology LLC. For more information, call (404) 973-2823, email john.kane@wyvernamerica.com or visit wyvernamerica.com.

Related Articles

Gage Repeatability and Reliability: Ensuring Accurate Test Results for Measurement Systems

QUALITY MEASUREMENT: Measure Completely and Accurately

How To Make Accurate Thickness Measurements!

Gage R&R (Repeatability and Reproducibility)

Related Events

Seminar: Light & Color Measurement

The Quality Show 2019

Related Directories

Accurate Technology

Starrett-Bytewise Measurement Systems

Dillon, Force Measurement Equipment

Measure-All MSI

You must login or register in order to post a comment.

Report Abusive Comment

Subscribe For Free!
  • Print & Digital Edition Subscriptions
  • eNewsletters
  • Online Registration
  • Subscription Customer Service
  • Mobile Help

More Videos

Sponsored Content

Sponsored Content is a special paid section where industry companies provide high quality, objective, non-commercial content around topics of interest to the Quality audience. All Sponsored Content is supplied by the advertising company. Interested in participating in our Sponsored Content section? Contact your local rep.

Close
Cncmachine__r0c0gpjprl__
Sponsored By
Renishaw Inc.

Renishaw and Hartford combine to deliver intelligent “smart factory” solutions

In the face of global skills shortages and rapidly emerging Industry 4.0 trends, Taiwanese CNC machine manufacturer Hartford undertook to develop an innovative, easier-to-use human machine interface (HMI) for its CNC machines. At the same time the company strived to ensure process measurement and inspection at its CNC machine manufacturing operations could keep pace with ever-improving product quality goals.

Popular Stories

JimGems

Positive Reinforcement

Ralco Industries

Quality 4.0: A Trend within a Trend

Quality Leadership 100

2019 Quality Leadership 100: Quality Takes the Lead

Quality Management

What is Quality Management and Why Does it Matter?

What is ISO 90001:2015

What is ISO 9001:2015 and Why is it Important?

BuyersGuide


Quality Magazine how to directory guide video

Events

March 14, 2019

Why Excel is Failing Your Tolerance Stacks

This webinar will demonstrate a 1D, 2D and 3D stack analysis on a product, and explain why 1D and 2D stacks are missing the mark for tolerance analysis
March 20, 2019

Vision Guided Robots: 2D vs 3D Technology

This session will review 2D technology for inspection and guidance, and highlight how 3D vision is being used for recognition of randomly presented parts in bin picking applications.
View All Submit An Event

Poll

Topics to Talk About

What topics would you like to see Quality cover more?
View Results Poll Archive

Products

Quality Brain Teasers: Real World Challenges to Build Your Manufacturing Skills (ebook)

Quality Brain Teasers: Real World Challenges to Build Your Manufacturing Skills (ebook)

Assessments and Training in the following areas...

See More Products

SoftwareDownloads

Quality Magazine

Quality February 2019

2019 February

Check out the February 2019 edition of Quality: Quality Leadership 100 survey results, air gaging, Quality 4.0, automation and much more!
View More Subscribe
  • Resources
    • Market Research
    • Custom Content & Marketing Services
    • List Rental
    • Partners
    • Manufacturing Group
    • Polls
    • Privacy Policy
    • Survey and Sample
  • Want More
    • Connect

Copyright ©2019. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing