Using scanners, computer-assisted design software, and three-dimensional printers can help manufacturers large and small in developing new products or improving existing ones, according to Derek Ellis, a senior applications engineer with Computer Aided Technology Inc.
In a presentation on advancements in additive manufacturing technologies — 3D printing being a prime example — Ellis said the benefits to a manufacturer are “time and money,” adding that “first to market always wins.”
During a three-hour session at the 2017 Work Truck Show in Indianapolis, Ellis and two of his colleagues went into detail about how they use modern scanners in design, reverse engineering, and 3D printing.
“Everybody in here has probably seen a 3D printer,” Ellis said. “But what we’re going to do is talk about the secondary applications that you can use still in the prototyping process before you go to manufacturing, where mistakes at that end of the spectrum cost you a lot of money.”
The product development lifecycle employed by Computer Aided Technology — which is headquartered in Buffalo Grove, Illinois — “starts with conceptualizing” an idea, followed by design, prototyping, and validation.
Prototyping pays off
Spending $2,000 on a prototype might seem like a lot of money, Ellis said. “However, when you start making mistakes or there are design changes in manufacturing, your costs triple. Easily.”
A design can be as simple as a sketch on a napkin, a model made of clay or cardboard, or a free computer-assisted design program, Ellis said. But his company uses more complex CAD systems, like Solidworks, which can analyze a design to determine if it’s manufacturable.
“It doesn’t do us any good if even on the computer screen when we’re trying to put parts together they don’t fit,” Ellis said.
It also pays to produce a prototype at this stage, he said. “If you find out in this stage that your gate is in the wrong location, or an insert is in the wrong location … that’s a cheap fix,” Ellis said.
Bob McGaughey, emerging products manager with Computer Aided Technology, holds an auto part for application engineer Bob Renella to scan during a demonstration
Bob McGaughey, emerging products manager with Computer Aided Technology, revealed that he actually did put a gate in the wrong position on a 3D-printed injection mold. The cost of the lost material was only about $150 fortunately.
“If that would have been tooling steel, you would have wrang my frickin’ neck,” McGaughey said to Ellis. “But because it was only 150 bucks worth of material, life was easy … We just threw it away and printed another one the same day.”
Another use of the technologies is competitive product analysis. Just as it sounds, this where you take a competitor’s product and analyze it by using a 3D scanner, said Bob Renella, an application engineer with Computer Aided Technology. That information can then be used to reverse engineer that product in a 3D CAD system, he said.
While that often involves expert tweaking, sometimes it’s even possible to take a scan directly to prototyping because most scanners create what are called stereolithography files, or STLs. “You can take an STL put it right on a 3D printer and print it,” McGaughey said.
Analysis enables substitution
It is also possible to use such a scan to perform an FEA, which stands for finite element analysis. An example of that would be if someone wants to substitute a different material for a particular part.
“You can do those quick what-if scenarios,” McGaughey said. “So you can say, OK, I did this out of say, high-density polyethylene but then I want to do it out of glass-filled nylon. Or you can say, ‘Well, it really needs to be cast carbon steel.’ You just simply go in there, right click and change the material and run the analysis again.”
In one example that McGaughey recalled, they scanned parts of an International truck — hood, fenders, and grill among other things. But the most important piece of information they needed was to determine the clearance between the motor and the underside of the hood.
“So we just disconnected the hood, set the hood to the side, scanned the motor, put the hood back on, lifted it up and scanned the hood underneath. The software still remembered that the hood was down when it was first assembled,” McGaughey said. “So it snapped the bottom of the hood and the top of the hood together as if it was still assembled. Then I was able to see I had a six-inch gap between the sound covering underneath the hood and the top of the motor. What they were wanting to do was put a supercharger in there.”
A variety of scanners
Ellis, McGaughey, and Renella brought a variety of 3D scanners to the presentation, including portable Go!Scan, HandyScan, and MetraScan devices from Creaform Inc. Headquartered in Lévis, Québec, Creaform is part of Ametek Inc., which acquired Creaform in October 2013. Ametek, which has annual sales of around $4 billion, is headquartered in Berwyn, Pa.
A Go!Scan scanner provides color and texture but has “looser accuracy” than more advanced models. The Go!Scan 20 is for small parts that can fit on a table, whereas the Go!Scan 50 would scan a table itself.
For semi-medium parts, they use a HandyScan 700, which is considered to be metrology grade — meaning it produces highly accurate measurements that meet International Standard Organization specs for quality control. For even larger parts, the scanner of choice is the MetraScan, which Renella said he used on recent job to scan cruise ship water inlet suction vents that were up to 40 feet tall.
“Using those two (smaller scanners) would have taken me more than a couple of days and a lot of headache to do,” Renella said.
At the Indy 500, small scanners are now used to inspect airfoils on the race cars, McGaughey said. What used to take up to half an hour per car when using aluminum templates now takes just five minutes with the scanner.
For most of the presentation, they focused on how to use the HandyScan 3D 700, which Renella said has an accuracy of plus or minus 30 microns and a resolution down to about 50 microns.
For the scanner to work requires affixing “positioning targets” to the part. These targets are preprogrammed into the hardware and software so that the scanner can recognize their diameter, thickness and reflectivity.
“The scanner itself is going to project a field onto the part, recognize those targets and start to create vectors from your parts, going back to your scanner,” Renella explained. “And then from there it can tell the relative distance of points across your surface on your part and it’ll start sending that back to your scanner.”
Software looks familiar
The software is where the data acquisition takes place, he added.
His demonstration used software called VXelements, which is proprietary to Creaform scanners.
“If you guys have ever used any CAD software, you’ll quickly recognize the user interface — it looks almost the exactly the same. That was the intended purpose,” Renella said. “They didn’t want you to spend a lot of time fiddling around with new software.”
Unlike other software that creates “point clouds,” VXelements creates surfaces. Where the use of point clouds requires creating lines to connect the points, the surface-creating software “gives you a real time visualization or feedback while you’re scanning,” Renella said.
Despite the recent advances in scanner technologies, Maughey noted, the ability to scan complex objects like people — as depicted in the movie Big Hero 6 — and create perfect duplicates without any software manipulation is a long way off.
“I’ve talked to the guys at a few other software companies and they all say that what we call the automagical button — hit it and all of a sudden you’ve got beautiful CAD models, exactly what you want — it’s 10 years off,” McGaughey said. “But every time you hear that, that’s 10 years out.”
Preserving legacy patterns
Scanning can also be used to get electronic data from sand-casting patterns, Ellis pointed out. Or a scan and reverse engineering can be used to tweak a product that was sitting on shelf.
Renella told of a company that had a warehouse with hundreds of foundry patterns, some predating the Second World War, but which had no associated CAD models or drawings. He asked the proprietor what would happen if a fire destroyed those patterns? “It would virtually put him completely out of business with one fell swoop of a flame,” Renella said. So he recommended scanning the patterns and backing up that data on multiple hard drives.
McGaughey cited a similar case of a furniture manufacturer that had five warehouses full of wooden patterns, some as old as 125 years. After a fire destroyed one warehouse, “They are scanning the other four warehouses like maniacs,” McGaughey said.
Later, in response to a question, Renella said that saving the data means that a new part can be reversed engineered in the future. Following up on that, McGaughey said it would be a good to begin with the 20 percent of parts that make up 80 percent of the company’s profit.
“You think about what parts would I need on Monday morning to continue working? And you have somebody start reverse engineering those. You just start with a few and you start building your way up,” McGaughey said.
Can an untrained 20-year-old worker do that scanning? an audience member asked.
“Absolutely,” McGaughey said, adding later that he has let his daughter and nieces use a Go!Scan machine.
“Anybody in this room can come up here and get data,” Ellis added.
Reverse engineering takes time
Learning reverse engineering, however, requires two days of training.
Reverse engineering is much more complicated, as they proved during a demonstration of how to scan a Plano case as well manipulate a file of Tonka truck that McGaughey had tweaked to fit the contours of a truck seat that Renella had scanned. (McGaughey had printed a 3D model of the Tonka but neglected to bring it to Indianapolis.)
By sending a mesh of the Plano model to the SolidWorks program, McGaughey was able to manipulate it, such as by stretching it or enlarging the size of a cupholder. Overall it had taken him 12 hours to produce three mockup designs and one actual prototype. That didn’t include the Tonka truck case, which he was able to model because he already had a virtual snapshot of it.
The nature of an item to be scanned determines how much manipulation it will require in CAD and how long that will take, he said earlier in the presentation.
“If I need a fully parametric CAD model of this with sketches, features, fillets, champers and everything else, you’re probably going to take more time,” McGaughey said. Some parts are simple enough that he can build a model in CAD just from basic measurements. “But there are some pieces of geometry like I don’t even know where the hell to begin modelling this part,” he added.
Reflective surfaces can play tricks with a scan, but that can be offset with a simple $3 spray can of talcum powder — or a $50 can of a proprietary spray. Creaform has also developed software that make the “rat’s nest of digital noise” disappear even when scanning something highly reflective or with surfaces of high-contrast areas, McGaughey said. Following up on that, Renella said he was able to accurately scan a clear glass pitcher containing water and ice cubes. “There was enough condensation that broke up the transparency that you could actually measure the surface,” McGaughey said.
— Keith Norbury