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PLANT

PLANT print issue: Adding another dimension to production

Digital technology is influencing the way things are being made, from prototyping to the creation of parts and components.


3D printers are responsible for making some pretty cool stuff these days.

The process produces three-dimensional objects from virtually any shape derived from a computer aided design (CAD) model using additive processes such as selective laser sintering (SLS), fused deposition modeling (FDM) or stereopithography (SLA) to lay down successive layers of material. It’s a significant departure from traditional machining that relies on the removal of material by cutting or drilling, and it’s being used in innovative ways.

Buttercup, a duck born with a backwards foot, now walks properly after being fitted with a 3D printed prosthetic foot thanks to a Tennessee-based manufacturer, while doctors are fitting patients with web-like casts to mend broken bones. There’s even a working prosthetic human ear, produced by researchers at Princeton University. It’s made from 3D-printed cells and nanoparticles combined with a coil antenna with cartilage using a $1,000, off-the-shelf 3D printer. And researchers at China’s Hangzhou Dianzi University went authentic with a printed ear cartilage sample using real human tissue. The university says about 90% of the printed cells survive for as long as four months.

Some dubious innovators have also produced 3D printed guns, including a Canadian (authorities are investigating), and some students at the University of Toronto who wanted to prove how easy it was to do and demonstrate the need for greater regulatory oversight.

And NASA is sending a 3D printer into space next year. It will be the first machine to make parts onboard the International Space Station.

3D printing, or additive manufacturing, is presently a $2.2 billion global industry, a jump of more than 28% from 2011, according to data from research firm Wohlers Associates. But will these Star Trek-like replicators be responsible for a third industrial revolution?

Such a claim is perhaps premature, but the technology does have the potential to alter the industrial landscape.

“We do know manufacturing is continuing to go digital and the speed of these technologies is increasing; the variety of materials is expanding, which leads us to believe the potential of micro-manufacturing presents great opportunity for manufacturing overall,” says Harold Sears, an additive manufacturing specialist at Ford Motor Co.

Finding its fit
Engineers at Ford, led by Sears and Paul Sussalla, section supervisor of rapid manufacturing, are convinced they’ve uncovered a way to make it practical.

When the automaker tasked its engineers to develop a more fuel-efficient engine, they turned to the nondescript Beech Daly Technical Centre in suburban Detroit where 3D rapid manufacturing was deployed to quickly produce prototype parts for what would become the EcoBoost engine. This shaved months off overall development time.

“Engineers who wanted to test metal parts had to wait weeks for a pattern shop to create the tools, send it to the foundry, make the piece and deliver it to the lab,” says Susalla. “If it didn’t work, the whole process started over again. Now an engineer in the prototype facility checks the casting patterns and cores as they come out of the printer.”

Rapid prototyping saves Ford millions of dollars a year by enabling engineers to test more part variations in less time without having to invest in tooling for parts that are likely to change. For the customer, this means better quality, weight-optimized products that improve fuel efficiency.

“There’s such a focus on weight and fuel economy in the automotive industry that 3D printing provides us with an optimal tool to meet those requirements,” says Sears.

Despite the obvious benefits it offers by streamlining design and prototyping, additive manufacturing continues to look for its place in the industrial space.

“3D printing isn’t the next face of manufacturing, its more of a complimentary technology because there’s no economies of scale with it,” says Reuben Menezes, a marketing manager at Proto 3000, a Woodbridge, Ont.-based supplier of 3D printers. “It’s still confined to small-run production, but it’s cost effective and will become more prominent as materials develop.”

Huge strides in the industry, led by a push in materials research, including the ability to print metals in 3D, will make the technology more useful to manufacturers, he adds.

“The adoption of 3D printing has been slower than expected,” says Doug Lee, 3D printer product manager at Oakville, Ont.-based Javelin Technologies, one of Canada’s largest 3D players. “It’s become key to being competitive in a global economy. The only way to be better is to design better products and get them to market quicker. The tools are there. But it amazes me the number of companies that aren’t adopting it.”

Mass customization
Advances in rapid prototyping have introduced the use of materials suitable for final manufacture, suggesting the possibility of directly manufacturing finished components, ideal for small-batch, inexpensive production. Rapid prototyping works by printing a part one thin layer at a time, gradually building up the finished piece – like assembling a spool of CDs. When the first CD is placed down, the spool is a fraction of the entire cylinder. Once the final CD is placed on top of the pile, a 3D object has been created.

But rapid manufacturing is a new method, many of its processes unproven, and mass production capabilities are limited because of the printer’s slow speed.

“Its hard for us to consider using these technologies in a production setting unless its low volume,” says Sears. “It gives us the option to optimize those tools further, and it’s ideal for test parts that go through frequent changes during development.”

The technology offers potential for mass customization using simple web-based software. For example, consumers are able to custom design a smartphone case and have it printed in 3D. Virtual CAD blueprints or animation modelling software “slice” them into sections as a guideline during the printing process.

The 3D process isn’t new. It has been around for a quarter century but is gaining traction as the technology advances and the price of equipment drops. So cheap in fact that consumer versions are available for less than $1,000. Commercial versions, however, can cost hundreds of thousands of dollars.

Moving ahead, the additive manufacturing market will be worth $8.4 billion by 2025, according to a study from Boston-based research firm Lux Research. That’s up from it’s current value of $2.2 billion, and its expected that much of the customer base will be industrial, with big adopters in automotive and aerospace.

The report, Building the future: Assessing 3D printing’s opportunities and challenges, suggests the technology will help manufacturers reduce raw materials costs. The actual amount of 3D printable material sold is expected to top 9,700 tons by 2025, up from 880 tons in 2012.

At Ford, 3D rapid manufacturing produces prototypes for everything from air vents to cylinder heads, allowing engineers to quickly create a series of evolving testable pieces with slight variations, while considering how the piece will affect mass production abilities.

Ford has also invested in one of the newest variations of this technology: 3D printing with sand.

Most recently, it produced many of the components for the 3.5-L EcoBoost engine in its Transit Van. Cast aluminum oil filtration adaptors, exhaust manifolds, differential carrier, brake rotors, oil pan, differential case casting and even rear axles were prototyped with the technology, specifically utilizing selective laser sintering (SLS), stereolithography (SLA) and 3D sand casting.

SLS applies a high-powered laser to fuse small particles or glass powders into a 3D mass. It’s used mostly in low-volume production of prototype models and functional components.

Fused deposition modelling (FDM) adds material in layers. A plastic filament or metal wire is unwound from a coil and supplies materials to an extrusion nozzle, which is heated to melt the material so it moves both horizontally and vertically by a numerically controlled mechanism. A model is produced by extruding small beads of thermoplastic to form layers, which hardens almost immediately.

SLA involves a vat of liquid ultraviolet curable polymer resin and an ultraviolet laser to build parts one layer at a time. The laser beam traces a cross-section of the part pattern of each layer. The laser cures and solidifies the pattern traced on the resin, joining the layer underneath.

SLS and SLA are good for producing trim and body parts for prototype vehicles and wind tunnel models, but SLA plastic parts won’t endure the high stress and temperatures of engine blocks and cylinder heads.

SLS parts are used for engine parts such as intake manifolds.

3D sand printing was also used to produce rotor supports, transmission cases, damper housings and end covers for HF35 hybrid transmissions used in the Ford C-MAX and Fusion hybrid sedan; four cycliner EcoBoost engines for the Ford Escape; brake rotors for the 2011 Explorer (modified late in the development process to address a brake noise issue discovered during durability testing), and exhaust manifolds for F150 pickups outfitted with 3.5-L EcoBoost engines.

It involves packing sand around the pattern of a 3D object, then removing the pattern to fill the mould with a liquid metal. As the metal solidifies, the cast object is formed.

Combining old and new
Ford is still using traditional casting, one of the oldest metal processes. By combining it with 3D printing, engineers have a cutting-edge method to quickly produce production-representative parts.

Conventional methods of producing the moulds for patterns take weeks or months, an expensive process. Each time a change is made to the prototype design, moulds have to be altered or new ones created, increasing costs. 3D printing with sand prints patterns and cores that are on their way to the foundry in a matter of days.

Ford may also eventually produce replacement parts for cars that have been years out of production. Currently, when a vehicle needs to be serviced, a dealer orders a replacement part from a warehouse and has it shipped. With 3D printing, dealers simply scan a barcode or print an order for the part on the internet, take it to a local supplier and have the part within hours, or even a few minutes.

“This is an amazing concept, and we’re excited to see how far we can take it,” says Sears.

Like the fictionalized replicators on-board the original USS Enterprise, the technology is boldly going where no printer has gone before.

This article appears in the Sept. 2013 edition of PLANT.

Comments? E-mail MPowell@plant.ca