Daimler may be the first vehicle maker to offer 3D-printed replacement parts, but racing enthusiasts and car collectors like Jay Leno have been using additive manufacturing and 3D scanning for many years to replace worn-out parts or to enhance their rides.
Daimler started 3D printing after-sales plastic parts for Mercedes-Benz trucks. The move eliminates the need to warehouse 30 initial items offered, including covers, spacers, spring caps, air and cable ducts, clamps, mountings, control elements and more this month. It also makes retaining and maintaining production facilities and tools for older truck parts a thing of the past, making them more readily and economically available.
The German automaker promises the number of replacements that are 3D-printed will grow, and the program may expand to include metal items and parts for Mercedes-Benz automobiles.
If it includes 1971 Mercedes 280 SE 3.5 coupes, it will surely please Leno, who hit a bump soon after he bought one.
A 90% Savings
When he needed to replace a cracked plastic knob used to control the air conditioner, Leno called Mercedes Classic, the restoration and support center for older models, and learned it wanted $500 for a replacement, said engineer Jim Hall, chief fabricator at Jay Leno’s Big Dog Garage (Los Angeles).
“He asked me, can we print these knobs?” said Hall.
Hall whipped out his calipers, made a CAD file in Geomagic Design X from 3D Systems (Rock Hill, SC), and subsequently printed a knob for about $50.
“He loves that,” Hall said of Leno’s reaction. “He can afford to pay $500, but he doesn’t want to.”
Hall, who has an aeronautical engineering degree from California Polytechnic State University in San Luis Obispo but has always been “enthralled with cars,” has worked at the Big Dog for 12 years. He’s been 3D printing since 2007, and estimates he’s printed about 200 parts, mostly for prototypes. He started 3D scanning in 2009.
“We’re fortunate in that we have these really cool toys, but don’t have to run them 24 hours a day (like a commercial shop would),” he said.
While he may print his prototype in ABS plastic, Hall jobs out printing for polycarbonate and metal parts. “ABS doesn’t like fuel,” Hall said.
Running With the Big Dog
In the garage, Hall started out with a Stratasys (Eden Prairie, MN) Fortus 250mc, but currently uses a Fortus 450mc for its bigger build envelope and the larger number of materials it prints.
“The 250 machine was a little easier to use,” said Hall. “It’s very valuable to have a smaller, easier-to-use machine for prototype shops, but the surface finish may not be what you want.”
The 450 is a bit more cumbersome to use, and takes longer to warm up because of its higher build temperature, Hall notes.
“If you want to change materials (in the 450), you can do that but it may take you several hours to change the tips and cartridge(s) and perform calibrations.”
When he needs to scan a part, Hall usually picks up his Faro (Lake Mary, FL) ScanArm, equipment he favors because rather than being a hand-held unit, the scanner’s attached to a digitizing arm.
“Because it is attached to an arm, the scanner always knows where it is in space,” said Hall. “That simplifies the math functions in the scanning software, and multiple scans can be fused into a solid with less processing.”
He’s also used the NextEngine (Santa Monica, CA) 3D scanner, a hand-held model that retails for about $3000.
“There’s probably a bit more learning curve on the NextEngine,” he said. “The software lines up most of the data, but mostly it felt like I had to manipulate it more. My scan wasn’t always watertight.”
3D Laser Scanning
Hall, whose hobby is racecar engineering, may be interested in some recent projects at 3D laser scanning company NVision Inc. (Southlake, TX).
Colin Ellis, engineering manager, said a client who wanted to use a late-model Corvette for racing needed a cowling to hide hoses connected to an extra radiator behind the car’s front bumper. The client had designed a part, so Ellis used his company’s HandHeld hand-held 3D scanner to scan the customer’s prototype and the car bumper.
“Scanning both sides of the front end, to ensure a tight fit, and scanning the handmade part took two-and-a-half hours,” said Ellis. NVision’s base charge for 3D scanning is $2,500 a day, Ellis said.
The software that comes with the scanner, Kube, processes the data to an STL file.
“Then Geomagic Design X uses the STL as a template to build the CAD model,” Ellis said. He then used a 3D Systems printer to make the part.
The Corvette owner isn’t NVision’s only client with a need for speed⅛—and 3D scanning.
In December, GSpeed (Cresson, TX), a racecar mechanic team, contracted with NVision to 3D-scan the chassis of a Dodge Viper that had already been modified and then banged up during 15 years of racing.
Knowing the actual geometry of the chassis was critical to designing a new suspension system and other modifications the team is working on.
“If the frame is off by as little as ⅛” (3 mm) from what we think it is, the performance of the vehicle will drop significantly and all our work will be for nothing,” said Jake Sieverling, GSpeed design engineer.
In previous projects, the company used hand measurements, which were accurate to within about 1/16″ (1.6 mm). NVision scanned the chassis at 12 times greater accuracy and with a 27% reduction in cost compared to the manual measurements, according to a company press release.
“I talked to four service bureaus and picked NVision because they use high-quality equipment that we are familiar with,” Sieverling said. “NVision technicians used [an NVision] HandHeld scanner attached to a mechanical arm that moved about the chassis, capturing data rapidly with a resolution of 0.001″ (0.025 mm).
“Knowing that the geometry we are working with is accurate gives us confidence that we can achieve our goal of building one of the fastest second-generation Dodge Vipers ever,” Sieverling said.