All Features
Rina Molari-Korgel
The Coordinate Metrology Society is pleased to post a diverse but technically packed week of presentations and activities for CMSC 2008. This year’s record number of 46 submitted abstracts has resulted in an exciting lineup for you, our attendees.The technical agenda commences with Jon Cowart…
Coordinate measuring machines (CMMs) are a basic requirement for any industrial manufacturing facility conforming to the specifications of drawings and standards. Accuracy needs to be observed, verified, and certified with respect to a comprehensive set of standardization rules. Highly precise…
CMSC
The Car of Tomorrow, a new racecar style for NASCAR’s NEXTEL Cup Series, made its debut in March 2007 with much fanfare. Seven years in the making, NASCAR’s research and development center rolled up its shirtsleeves and conceptualized their dream template. Their ideal racecar would implement the…
William Tandler
Encoding the mating flange:
In Workshop No. 7, we used Smart GD&T processes to encode the operation, assembly, and other functions of a flange. In this workshop, we take a deeper look at the mating aspect of the game by encoding the mating flange. The additional steps, 7 through 9, are…
William Tandler
T
he actual purpose of GD&T:
It’s common to think that the primary purpose of GD&T is to unambiguously communicate design intent to manufacturing and inspection. In fact, the most important objective is to ensure that what we communicate is worth communicating, and that it…
William Tandler
What’s a datum reference frame?
As discussed in workshop No. 5, datum reference frames (DRF) are coordinate systems, and preferably—at least to start with—Cartesian coordinate systems.
As we know, coordinate systems serve to orient and locate objects, and in the world of GD&T in particular…
Fred Mason
It’s becoming common to refer to the devices used for dimensional and coordinate measurement—vision/optics, lasers, touch probes, and others—as sensors. Multisensor measuring systems use two or more of these devices. It can be confusing because none of these “sensors” is actually a sensor. The…
FARO
At rare moments, an idea comes along that makes people rethink how jobs are done from that point on. The engineers at Falk PLI Engineering & Surveying have hit on such an idea for one of the most basic concepts of all: measuring.
The larger-than-life nature of steelmaking would seem to belie…
With the ever-growing demands of energy, the demands on high value-added vessels, such as container vessels, liquefied natural gas (LNG) carriers, and crude oil carriers, have skyrocketed in recent years. As of 2006, shipbuilding orders received by South Korean shipbuilders accounted for 42…
Rina Molari-Korgel
Welcome to the second issue of CMSC World—the place to catch up on the latest happenings in portable 3-D metrology and imaging. This is the official newsletter of the Coordinate Metrology Society, and once again we are gearing up for our Coordinate Metrology Systems Conference—“the” conference…
How much is a kilogram?
It turns out that nobody can say for sure, at least not in a way that won’t change ever so slightly over time. The official kilogram—a cylinder cast 118 years ago from platinum and iridium and known as the international prototype kilogram or “Le Gran K”—has been losing…
Fred Mason
In dimensional measurement it isn’t unusual to measure feature locations relative to reference edges. How one measures an edge depends on how we define it. So what exactly is an edge? Basic edges Back when people thought the world was flat, they feared that explorers who ventured out to sea might…
William Tandler
As we know, GD&T is a symbolic language with which to specify permissible limits of imperfection in manufactured parts, namely limits that maximize the parts’ operability, assemblability, and affordability. It’s complex only to the extent that the real world of imperfect geometry is complex. If…
Anne Willimann
The Airbus A380 is the most modern, spacious, and capable civilian aircraft ever. The project was launched in December 2000, christened “The Flagship of the 21st Century,” and developed in close cooperation with air carriers, airports, and air traffic authorities.
The A380 incorporates the most…
William Tandler
Back in the 1940, when Stanley Parker, Mr. GD&T, decided it was time to create a set of tolerancing tools that realistically dealt with reality, two objectives were near the top of his list.
The first was to find a way to encode the fact that as bores get larger they may become ever more offset…
Fred Mason
Happy New Year! One resolution many people have made is to cut costs. One way to do that is to manufacture in China. Just transfer your current manufacturing processes, use China’s lower-cost labor, and increase profits. It’s not that easy. If you rush into it you may find costs actually go…
William Tandler
Our original plan for workshop No. 3 was to discuss what are generally referred to as material condition modifiers, namely the encircled letters “M,” “L,” and “S” which sometimes follow tolerance values and sometimes follow datum-feature labels in feature-control frames. The idea was to explain…
Fred Mason
During this annual holiday shopping melee, economists project the implications of our spending for the country’s overall economic health in the coming year. That can be like claiming a warm December day proves global warming. What does this have to do with measurement? Quite a bit, actually,…
Neven Jeremi
Dirk Noffke, a metrology technician at DaimlerChrysler Bremen, inspects the dimensional accuracy of the left fender on a Mercedes SLK body-in-white. The comparison between the actual and CAD data is displayed in real time on an application PC running the PolyWorks…
Belinda Jones
The 23rd Coordinate Metrology Systems Conference convened at the Grand Sierra Resort in Reno, Nevada, July 16-20, 2007. The CMSC Society hosts this gathering each year. The organization is comprised of 3-D measurement technology professionals, service providers, and original equipment…
Rina Molari-Korgel
The CMSC is proud to sponsor this inaugural issue of CMSC World, an electronic information guide for users of industrial, high-precision, 3-D measurement technology. This quarterly e-newsletter will deliver the latest metrology industry news, best practices, new techniques, product and personnel…
William Tandler
Continuing with our analysis of the Greatest Design Tool ever, our objective in this article is to take a detailed look at the structure and contents of feature control frames to demonstrate that they represent “encoded” information which may only be “decoded,” not “interpreted.” With their…
Fred Mason
You manufacture a part that must be within design tolerances to work properly, so you need to measure it. It costs to: Buy the measuring device Provide a space and/or utilities for it Develop fixtures or part-holding accessories Make sure people are trained to do the measurements Develop…
William Tandler
What is GD&T, anyway? The Greatest Design Tool ever, or a whole bunch of Gol-Derned Trouble? Actually, geometric dimensioning and tolerancing is both, and worth every penny.
Only with the help of GD&T can we test and guarantee the functionality of parts and assemblies on the design…
Fred Mason
Many measurements assume that a measuring device performs in the same way throughout its measuring range. In other words, a 1 mm distance measured near the center of a machine will measure 1 mm at its periphery. But will it? This column discusses some of the factors that can cause nonlinear…
