It’s often assumed that confidence in a measurement equates to confidence a product conforms. However, we can only measure at discrete points on a surface, while GD&T relates to the entire surface. We don’t know what is happening on the surface between the measured points. This is known as the intrinsic uncertainty of the measurand.…

Continue Reading Intrinsic Uncertainty: The Elephant in the Room

Composites offer significant advantages where high strength and low weight are required. These materials are, unfortunately, also very difficult to recycle. Composites consist of fiber reinforcement embedded within a polymer matrix. The polymer may be a thermoset, such as epoxy, or a thermoplastic, such as polyester. Separating the fibers from the matrix is a huge…

Continue Reading Low-Cost Recycled Composites for Automotive

Achieving right-first-time manufacturing requires regular calibration and verification of production machinery. On-machine measurement makes this even more important. Achieving rapid, automated and fully traceable calibration of machine tools is a priority for high-value manufacturing. The Etalon Multiline system gives this capability. To carry out a calibration, the machine must only move its spindle or probe…

Continue Reading Etalon Multiline Enables Self-calibrating Machine Tools

In this article, I show that the conventional method for calculating uncertainty is not always reliable. In fact, it is generally only exact when the measurement can be represented by a simple linear equation and the input uncertainties are all normally distributed. Whenever the measurement is more complex, there will be errors in the way…

Continue Reading Why simulation is the future of uncertainty evaluation

When I’m designing a linkage mechanism I often have some particular motion that I need to achieve. In this article I explain the first step in this process, defining the joint positions and linkage lengths required to produce a particular motion. I have found that the constraint-based sketcher within SolidWorks provides an ideal tool for…

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Frequency scanning interferometry uses a tunable laser to provide highly accurate distance measurements. It was first developed by researchers at the University of Oxford who were working on the Large Hadron Collider at CERN. The UK’s National Physical Laboratory (NPL) has taken this state of the art technology and developed it into a much more…

Continue Reading NPL Brings Frequency Scanning Interferometry to Large-Scale Manufacturing

The VDA-5 standard is a big step forward for the evaluation of industrial measurements. It combines the practicality of gage studies with a rigorous uncertainty evaluation approach. This is definitely heading in the right direction, although the methods it uses can still miss some important sources of uncertainty, as I will show towards the end…

Continue Reading VDA-5: Combining Uncertainty Evaluation with Gage Studies

A new £8 million research project, led by GKN Aerospace and backed by the UK’s Aerospace Technology Institute (ATI), is focusing on developing and demonstrating robotic and digital technologies required for the next generation of aircraft wing manufacturing. Read the full article, published on engineering.com…

Continue Reading Developing Automated Assembly & Inspection Technology for Aircraft Structures

There has been huge excitement in recent years about new forms of carbon such as graphene, carbon nanotubes and Buckminsterfullerene (buckyballs). This article looks at the new forms of carbon, such as nanotubes and graphene, and considers whether we may be on the verge of a carbon revolution. Read the full article, published on engineering.com…

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A novel optical 3D scanner called the Hexagon Blaze 600A has been developed to overcome conventional issues with the noncontact measurement of composites. The system is designed to be integrated with a robot to provide fully automated inspection. Read the full article, published on engineering.com…

Continue Reading 3D Scanner Designed for Fully Automated Inspection Begins Testing

Researchers are developing ways of using machine learning to adjust process parameters in automated composites manufacturing. This is removing the need for human intervention and improving quality. Read the full article, published on SAE.org…

Continue Reading AI closes the loop for composites manufacturing

Frequency Scanning Interferometry (FSI) was invented to measure movements of the detectors in the Large Hadron Collider at CERN. Now a team at the UK’s National Physical Laboratory are developing a practical FSI based instrument for large-scale manufacturing. This may enable the next generation of aircraft with natural laminar flow wings and part-to-part interchangeable assembly. Read…

Continue Reading An instrument going from ‘Big Science’ to large-scale manufacturing

A gage study involves real measurements of a calibrated reference, so many people feel it is a completely reliable metric for instrument capability. However, in this article, I use real examples to show how a gage study can get things wrong and how uncertainty evaluation can give a better understanding of variation and bias in…

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This article follows on my previous introductions to uncertainty and uncertainty budgets. It goes into more detail about some of the more tricky aspects of uncertainty budgets. I first explain what sensitivity coefficients are and then use examples to show exactly how sensitivity coefficients can be calculated and used within an uncertainty budget. Read the full article published…

Continue Reading Sensitivity Coefficients in Uncertainty Budgets

If you’ve ever been involved with an industrial measurement process, chances are you’ve come across Gage studies and in particular Gage Repeatability and Reproducibility (Gage R&R). These tests are used to determine the accuracy of measurements. In this article I provide an overview of these studies and how they relate to other methods such as uncertainty…

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This is a detailed article explaining how you can calculate an uncertainty budget. It follows my previous introduction to Metrology and Quality in Manufacturing. My previous article introduced the idea that all measurements have uncertainty. This uncertainty stems from different sources, including repeatability, calibration and the environment. To find the uncertainty of a measurement result, we…

Continue Reading Calculating Your Uncertainty Budget… on engineering.com

In this detailed article, I  introduce the basics of maintaining quality. This involves quality assurance, quality control and metrology. We use quality assurance to gain confidence that quality requirements will be fulfilled. Quality control is used to check that requirements have been fulfilled. This is a subtle difference and, in practice, the terms are sometimes used…

Continue Reading An Introduction to Metrology and Quality in Manufacturing on engineering.com