Inventor of the Articulated Arm Homer Eaton Introduces a Revolutionary Portable Automatic CMM


Forty years after his first invention, Eaton brings automation and accuracy to the portable measurement world with the zCAT.



Homer Eaton wanted to develop a portable, easy to use, automatic 3D measurement machine. After spending many years stringing thoughts and ideas together, technology finally caught up with Eaton’s dreams and allowed him to achieve his goal with his latest invention. The zCAT is the world’s first truly portable direct computer control coordinate measuring machine (DCC CMM).


Weighing only 30 lbs., the zCAT is incontestably unique in the measurement world for many reasons, but ultimately what sets it apart is that it is the first direct computer control CMM that can take automatic measurements with accuracies that rival the capabilities of larger, more expensive CMMs—all conducted by anybody with a very basic understanding of geometry, anywhere it’s needed.


Eaton’s industry changing invention has been decades in the making. Long before he conceptualized the zCAT, Eaton’s observations and experiments in his youth were paving the way for him to become an accomplished inventor in the modern industrial world.


Born in 1940, Eaton grew up on a farm between Hamilton and Oxford, Ohio on Old Oxford Road surrounded by loads of equipment and machinery. Eaton, his parents, two brothers and one sister, called an aged service station at the corner of the farm home. With endless equipment and tools lying around, Eaton enjoyed experimenting, fixing and creating throughout his adolescence.


He went to a small high school right next to the farm. In fact, Eaton’s grandfather gifted the township two acres of land in order to build the school, and his family remained caretakers of the property. It was there that Eaton became fascinated with cars and all the parts to go along with them. He learned to bend and solder exhaust tubes for himself and his friends to install dual exhaust systems, and he became fascinated with bend geometry.


After attending school and working at a manufacturing company in Ohio, Eaton was offered an opportunity to work for a California-based electronics company in 1966. In their early 20s, Eaton and his wife Nina, packed up all of their possessions and moved westward to start their new life. Then, in 1974, Eaton was granted patent number 3,944,798 for his invention of the Vector 1 tube measuring arm to which all other measuring arms since that time owe a debt.


The idea for the Vector 1 hit him one day like a bolt of lightning while on a fishing trip with a colleague and their wives in Mammoth Lakes, an idyllic town in the middle eastern part of California bordered by the Ansel Adams and John Muir Wilderness areas. “There I was, out sitting on a log, just waiting and ‘wham’ the idea hit,” recalls Eaton. With the tireless support of Nina, his wife of what is now more than 53 years, Eaton erected the first prototype of his invention in the couple's living room.


The original bench-mounted Vector 1 addressed a problem that Eaton had long been trying to solve: measure the bend geometry of an exhaust pipe or other bent tube. In the mid-80s, Homer Eaton and Romain Granger partnered together and produced the next generation of the Vector 1, the Romer articulated arm. The invention changed the quality control and measurement industry unlike any other product before it.


As decades have passed, Eaton has continued to design and think. The articulated arm is portable but manually operated, and Eaton wanted to develop something that could take automatic, accurate, repeatable measurement right to the part, significantly reducing user error and training time.


“I’ve always loved automation and I watched the evolution of it growing up on the farm,” Eaton explains. His appreciation for automation began by observing and using the automated equipment that his father would bring on to make their lives easier as technology improved. “Every time we got a new piece of equipment it meant less work for me and there sure were a lot of innovations that came in through the farm over those years,” he says.


The World’s First Portable DCC CMM


The idea for the zCAT was much less spontaneous than Eaton’s previous invention. He put together countless concepts and abstractions on how he could come up with a way to automate the portable measurement process. “I had been hoping to retire by the age of 75, but I just couldn’t pass up this opportunity,” he laughs.


Eaton’s invention is like nothing in the current measurement world because of its portability, automation, accuracy, ease of use and cost of ownership. At less than 30 lbs., the device allows operators to take complicated 3D measurements automatically, anywhere in the shop, on the plant floor, or even on a desk or conference table.


“I really wanted to have an automatic DCC machine, because accuracy goes up when you have that, and being able to have anyone operate the machine from anywhere was so important,” Eaton says.


The zCAT can be conveniently deployed directly in the manufacturing process or engineering process. No longer does production need to stop to measure a part or require a dedicated operator. Measurements can be taken quickly and automatically at the point of production. During the design and engineering process, CAD designers outputting directly to 3D printers can check the 3D print with a zCAT and quickly make changes within the CAD if needed, allowing them to remake the part without ever missing a beat.


Eaton says it is the use of rotary motion as the primary axis that allows the 620-mm-tall zCAT to have such a small footprint without taking away performance. The zCAT moves around its 172-mm base, and can rotate 360-degrees to take measures all around its perimeter.


Contributing to its portability, the DCC CMM is battery powered, able to run up to 4 hours before needing a charge. Furthermore, the device arrives in a reusable container, allowing customers the option to ship the zCAT back to the manufacturer for service instead of waiting days or weeks for a service appointment in house such as with a conventional CMM.


Changing the Production Process


One of the aspects of the zCAT that Eaton is most proud of, is its true out-of-the-box nature. With conventional CMMs, set up time and training can be a time-consuming and expensive task. The zCAT’s intuitive icon-driven touchscreen permits most users to take simple measurements within 15 minutes of training and to put together more complicated programs within a couple of hours. The same person making the part can now measure the part, and most importantly they can do that accurately and repeatedly. The DCC technology allows operators to teach the machine what they want to measure and then allow the device to take over.


The zCAT boasts a diametral accuracy of 3.0 + (D/100mm) and a linear accuracy of 5.0 + (L/100mm). It’s direct computer control allows the zCAT to be 3 to 5 times more accurate than a portable, articulated arm CMM, according to Eaton.


Another unique quality to the zCAT, which contributes to its intuitiveness, is the open architecture platform. “Very early in development, I decided I really wanted this to communicate with the type of software that people have in house. It’s helpful to have a device that can communicate in ways that you already understand,” Eaton says.


Operators can make use of the ControlCAT metrology software included in the device or take advantage of its I++ Software interface. In addition, the zCAT’s open architecture I++ software interface gives it the capability to communicate with many industry standard CMM software packages. Fowler will offer the powerful and easy to use MK4 zCAT 3D software as an optional item. Along with its modules it will allow customers to do 2D and 3D sophisticated measurements. As the zCAT measures the MK4 will draw the part on the screen. CAD programming module, Offline programing, CAD Comparison, Statistical Analysis and Reverse Engineering will all be available.


In addition, with its WiFi capability each zCAT has its own unique network, allowing the device to automatically transfer data in whatever form is desired. Users can even download measurements right to an Excel spreadsheet with the included zCAT Wedge Excel export software.


Finding the Right Partner


Though Eaton had a revolutionary design on his hands with the zCAT, he still needed a marketing partner to help him take it to the masses and educate the industry. During the development of the zCAT, Eaton—with the help of his partner Henry Krauss—found Fowler High Precision of Newton, Massachusetts and the two sides kept closely in touch throughout the process.


“It really has been a natural match,” Eaton says. “I am just so impressed with [Fowler’s] skills and reputation in the industry and they have the knowledge to go with it.”


Fowler High Precision is globally recognized as a leading supplier of high-quality inspection, leveling, control and calibration equipment. The company, in business since 1946, represents well-known brands in the industry such as Wyler, Sylvac, Bowers and Trimos throughout the United States and Mexico.


“The zCAT is such a great fit for Fowler, because our customers are looking for a product exactly like this,” says Jeff Petersen, vice president of sales at the company. “It allows customers to do more and solve their measurement problems.”


Both parties agree that the zCAT will help many companies save significant time and money, while delivering accurate, repeatable measurements at the source. For Eaton, who is resigned to the fact that he’ll never retire, he sees a very exciting future for the world’s first portable DCC CMM.


“I see a lot of accessories and additions to the zCAT in the future,” he says. “We haven’t even touched on some really cool things such as the camera world. We will certainly explore other probing methods and techniques including noncontact measurement. There is so much to do right there.”