zCAT Introduction Caps Off More Than Four Decades of Development
The zCAT direct computer control coordinate measure machine, or DCC CMM, is designed to be smaller and portable compared with traditional CMM devices. It has been in the making for more than four decades.
The zCAT traces its origins to Homer Eaton inventing the Romer Arm in 1974. The arm was a way to measure large objects, such as aircraft, without taking them to a measuring device. After finishing it, “I immediately realized the advantages that a motorized and computer-controlled version of it would offer and I went to work on it,” Eaton said.
The technology, however, wasn’t yet in place to turn those ideas into reality. Now, in the 21st century, Eaton’s idea has taken the form of the zCAT DCC CMM machines produced by Fowler High Precision.
The zCAT is 24.4” (62 cm) tall, with a diameter of 6.8” (17 cm) and weighs 30 lb (13.5 kg). It can be taken around the factory floor as needed. It also can be untethered from a power outlet because of a lithium ion battery that can operate the device for more than four hours between charges.
“I’ve taken it to customers and put it on their desks to measure parts,” said Jeff Petersen, Vice President of sales of Fowler High Precision. “It’s really interesting when we get it in front of the end user. You can see their mind thinking about how they can use it, where they can use it.”
What follows is how the zCAT was developed.
The story begins with Homer Eaton, born in 1940. He grew up on a farm between Hamilton and Oxford, Ohio, and lived at an old service station at the corner of the farm. Eaton had access to equipment, tools and car parts.
“I’ve always loved automation and I watched the evolution of it growing up on the farm,” Eaton said. “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.”
By 1966, he moved to California to work for an electronics company. He was granted a patent for inventing the Vector 1 tube measuring arm, often referred to as the Romer arm.
“I was trying to measure the geometric path of a bent tube shape, rather than the difficult convention of measuring the component features of lengths and angles,” Eaton said in an interview with Hexagon Metrology and published on that company’s website (http://www.hexagonmetrology.us/applications/technical-resources/metrology-101/769-the-origins-of-the-articulated-arm-cmm).
Twelve years later, Eaton and Romain Granger devised the next-generation of the Vector 1, the Romer articulated arm.
“In the late ‘80s, Romain Granger convinced me that we could build an even lighter unit and fold it into a more compact shape by adding one more axis,” Eaton said in the Hexagon Metrology interview. “It was about this same time Toshiba introduced the portable computer.”
Eaton also told Hexagon that he preferred inventing hardware over software.
“It is more tangible, challenging and creative,” Eaton said in the Hexagon interview.
Eaton continued to devise concepts for ways measuring devices could be automated. “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.”
In the late 2000s, efforts to develop what would become the zCAT were underway. Eaton and Fowler High Precision, the Newton, MA-based company founded in 1946, joined forces to develop what would become the zCAT.
Fowler is a supplier of inspection, leveling, control and calibration equipment. It represents brands in the industry such as Wyler, Sylvac, Bowers and Trimos throughout the United States and Mexico.
“It really has been a natural match,” Eaton said. “I am just so impressed with (Fowler’s) skills and reputation in the industry and they have the knowledge to go with it.”
Fowler executives also held Eaton in high regard.
“When Homer brought this to me years ago, I thought it was perfect,” said Petersen, the Fowler vice president of sales. “It really made sense to get this on the shop floor.”
What followed included “a lot of prototype, a lot of trial and error,” Petersen said. “We had to put the manufacturing together.” Fowler ended up producing the zCAT entirely in the United States.
The zCAT has a rotary encoder in the base to support 360-degree rotation, allowing parts to be nestled around the device’s perimeter and measured all at once.
It has a 10.8 volt lithium ion battery, which can be recharged in about an hour. It’s expected that customers will use zCAT much of the time while plugged into a power source. The battery however gives users the options of unplugging the zCAT to use it where needed. This would be similar to how users of laptop computers spend much of their time with the computer plugged in but can and do work on battery power as necessary.
The device also has Wi-Fi capabilities to permit the zCAT to transfer data wirelessly to a personal computer. The data can be transferred in any format, including directly to an Excel spreadsheet via the included zCAT Wedge Excel export software.
Also part of the zCAT is a touch-trigger probe system, designed for reliability and repeatability. An industry standard Renishaw TP20 probe system rotates 360 degrees and the horizontal styli can spin and orient to each part to be measured.
The zCAT was designed with a smartphone-sized touchscreen featuring icons and ControlCAT geometric measurement software. The idea was that users would only need 15 minutes of training to take simple measurements and a few hours of training to use more complicated programs.
Within a day or two, an experienced operator could be completely trained on the zCAT. All training could be done on a customer’s site. The same person making a part could use the zCAT to measure it as well, repeatedly and accurately. The DCC technology enabled operators to teach the machine what they want measured, with the device taking over the task.
What’s more, a patented clutch system allows for easy switching between direct computer control and manual control operation without flipping switches or pressing buttons. The device also has a “teach and repeat” mode. With that mode, users move the probe manually to the points of measurement. The zCAT can then save and repeat the program at machine speeds up to 150 mmps.
Operators can write measuring programs on the zCAT. Once such a program is written, the device takes over, ensuring repeatable results.
“Accuracy-wise” says Petersen, “We are finding that the zCAT under direct computer control can give us a repeatability of 3 to 5 microns. That same direct computer control also allows the zCAT to be 3 to 5 times more accurate than a portable articulating arm CMM”.
In addition to the ControlCAT software, the zCAT is equipped with an I++ Software interface, giving the device the capability of communicating with many industry standard CMM software packages.
“Very early in development, I decided I really wanted this to communicate with the type of software that people have in house,” Eaton said. “It’s helpful to have a device that can communicate in ways you already understand.”
As a result, the zCAT’s capabilities can be expanded to include automatic measurement routines, 2D and 3D inspection, DXF data import and export, real-time SPC, GD&T dimensions and tolerances, real-time SPC and other features.
Fowler also decided to offer MK4 zCAT 3D software as an optional item. Along with its modules, it will allow customers to do 2D and 3D measures. As the zCAT measures, the MK4 will draw the part on the screen.
In addition, Fowler moved to offer a CAD programming module, offline programming, CAD comparison, statistical analysis and reverse engineering features.
“It took it to the next level,” Petersen said.
By early 2014, Petersen was taking the zCAT to customers to gauge their reaction. “I was carrying it in a Samsonite suitcase.” At this point, no selling was taking place.
Reaction was enthusiastic. “What a lot of companies want to do is measure parts right on the floor and not take it to the CMM,” Petersen said. “We’ve taken it to end users, the ones actually measuring their own parts they’re making.”
The zCAT’s technical features mean that lengthy calibration isn’t necessary. With traditional, non-portable CMMs, calibration, set up and training time would take up to eight weeks before the machine went into operation. Also, a customer could own two or three zCATs for the cost of a conventional CMM.
Also drawing interest of potential customers was the touchscreen and the ability for users to write programs easily.
“It’s all icon driven,” Petersen said. “If customers understand simple geometry, they can be programming.”
In early 2015, Fowler sold “a couple of pre-production models,” Petersen said in September. “The first production models are coming out as we speak.”
A broader sales effort is underway. “I have a few dealers involved in this,” Petersen said. “I’ve gone to them individually. They’ve taken it to customers. They’ve given me numbers that are pretty exciting. I hate to throw a number out there. We can sell multiple units every month. We’re getting set up so we can move one every day. We’ve had multiple customers already give us orders for multiple units.”
Fowler is marketing the zCAT both for manufacturers wanting to save space and cost compared with traditional CMMs as well as companies looking to complement their existing CMMs.
The company says customers will save money by not having to pay license fees and upgrade charges. The zCAT also will be shipped in a reusable container, which can be used to send the machine back to Fowler for service.
According to Fowler, the zCAT will allow customers to streamline manufacturing and engineering operations and improve quality control.
In September, the first shipments began to go out to customers. “There isn’t anything else on the market like it,” Petersen said. “It’s new technology.”
Fowler also began a website, www.zCAT.com, where computer animations are used to demonstrate the zCAT’s features and benefits.
Eaton, in the meantime, is already devising improvements for future models of the zCAT.
“I see a lot of accessories and additions to the zCAT in the future,” Eaton said. “We will certainly explore other probing methods and technologies including noncontact measurement. There is so much to do right there.”