By Mark Shortt, Design-2-Part Magazine
The ‘Wow!’ factor is still strong, but engineers and designers are thinking about 3D printing in new ways, from evaluating its business value to learning the ropes of designing for additive manufacturing.
Offering the ability to make complex parts that can’t be made any other way, 3D printing technology continues to amaze people who are seeing it in action for the first time. For first-timers, watching an intricate part get built up layer by layer, without tooling, can be a revelation.
“Generally, it’s just astonishment because they have the idea in their head, they might have a rough sketch on a piece of paper, and then we’ll show them a CAD model picture,” said Zak Glaeser, vice president of FH Design & Engineering (www.fhdesignandengineering.com), an Ivyland, Pa., company that uses 3D printing to produce prototypes and sample parts for customers. “So they go from their sketch to the picture on the computer, and then they actually get to hold the part that they’re looking at in their hand. And it’s just kind of amazement that, from a span of a couple of days, they went from their napkin drawing to their actual idea, physically, in their hand.”
The latest developments in 3D printing, also known as additive manufacturing, highlight some of the many ways that the technology can benefit design, product development, and manufacturing projects through significant reductions in lead time and cost of tooling, as well as the ability to make parts that can’t be made any other way. In one of the most interesting developments, a Silicon Valley-based startup is currently attempting to shatter 3D printing’s current limitations on speed and mechanical properties with an entirely new approach to building objects (see New Mind-Bending Technology Grows Parts from Pool of Liquid Plastic).
Real Parts Are Flying
To gauge how 3D printing will be used by manufacturing companies in the future,Stratasys Direct Manufacturing recently surveyed 700 designers, engineers, project managers, and executives who work for companies that either already use 3D printing technology in their operations or plan to do so in the next three years. One of the key findings of the survey was that the majority of respondents—currently working in the aerospace, automotive, consumer, and medical sectors—indicated they “strongly believe that more end-use parts will be designed specifically for additive manufacturing in the future.”
According to Jim Bartel, senior vice president of business development and marketing for Stratasys Direct Manufacturing, the finding validates the company’s efforts to build up its capabilities for producing additively manufactured end-use parts. “It’s nice to have that validation and confirmation,” Bartel said in a phone interview. “We’ve been working with, and continue to work with, customers on end-use part production across almost every vertical market you can think of, particularly aerospace, transportation, and medical, but primarily aerospace. The trend for more end use part production is definitely a big trend, and it will continue.”
Industry analysts expect strong growth in metal end-use parts manufactured by 3D printing, especially for the aerospace industry. An example of a metal production (end-use) part is this heat exchanger, created by Stratasys Direct Manufacturing’s use of Direct Metal Laser Sintering (DMLS). Photo courtesy of Stratasys Direct Manufacturing.
Stratasys Direct Manufacturing released the results of the survey in its report, “Trend Forecast: 3D Printing’s Imminent Impact on Manufacturing,” which seeks to identify the 3D printing applications, equipment, materials, and services—as well as its business benefits and challenges—that are important to committed users of the technology. Among other results, respondents indicated that they expect the use of metals in additive manufacturing to “nearly double over the next three years.”
Strong growth in metal additive manufacturing is also forecast by veteran industry analyst Terry Wohlers, co-author of Wohlers Report, the annual worldwide progress report on the state of the 3D printing and additive manufacturing industry. In a phone interview, Wohlers characterized metal additive manufacturing as “smokin’ hot,” referring to a 55 percent growth rate last year that shows no signs of slowing down.
“If anything, there’s acceleration, especially when you begin to look at companies that are manufacturing today and preparing to manufacture in fairly significant volumes in the near future,” Wohlers told D2P. “Companies are buying multiple machines to meet their needs, and in some ways, the metal additive manufacturing has come further in ten years than the polymer additive manufacturing has in 25. What I mean by that is the traction that it’s gained, the amount and kinds of parts that are being produced, and the quality of the metal that’s being put down.”
Wohlers said that the quality of the metals currently being produced in additive manufacturing is on par with, and in many cases, exceeds the properties of cast metal. Manufacturers are obtaining near full density of the parts and can ensure there’s no porosity through processes such as hot isostatic pressing (HIP). Aerospace companies are among those that are using HIP to ensure the absence of porosity in the parts, he said.
“There are a number of parts that are flying already, and Airbus believes they’ll be 3D printing 30 tons of metal per month by 2018,” Wohlers said. “That’s only two years away—30 tons! That’s the kind of commitment the company is making to the technology, and a host of others are as well. So we’re very excited and encouraged with the developments around metal.”
A metal part created via Laser Sintering. Photo courtesy of Stratasys Direct Manufacturing.
Manufacturers to Service Providers: Don’t Abandon Us
The majority of respondents to Stratasys Direct Manufacturing’s survey also stated that regardless of their company’s in-house additive manufacturing capabilities, they believe there will always be value in partnering with an additive manufacturing service provider to augment their in-house 3D printing capabilities. When asked what they believe to be the top benefits of outsourcing additive manufacturing, 73 percent of survey respondents cited “access to advanced equipment and materials.” Other common responses included “less investment risk” (60 percent), “parts not able to be manufactured internally” (53 percent) and “access to additive manufacturing expertise” (47 percent).
“Even those who have in-house additive production are still looking for that expertise and know-how that a service provider has,” said Bartel. “As a matter of fact, a lot of the Stratasys machine owners [who are customers of Stratasys Direct’s parent company, Stratasys] also use Stratasys Direct Manufacturing. In a lot of cases, it’s for overflow work: They run out of capacity internally, so they turn to us for overflow production. They also come to us for expertise and know how.”
The report identified the aerospace and medical industries as most likely to grow their in-house additive manufacturing over the next three years, and the consumer and energy industries as most likely to increase outsourcing of additive manufacturing during the same time frame. It also said that respondents were particularly attracted to outsourcing processes—such as Direct Metal Laser Sintering (DMLS) and Laser Sintering (LS)—that require more post processing. This finding, along with the higher cost of purchasing additive metal machines, could help explain why the energy industry is expected to increase its use of additive manufacturing service providers. The energy sector has a high demand for metals additive manufacturing, Bartel noted.
“The energy sector, and oil and gas in particular, need heavy-duty, real metal parts, just like they’ve been getting casted part for years for a lot of their applications,” Bartel said. “And when you look at the cost of metals machines, they are higher priced today than some of the plastics technology. So the barrier to entry for existing manufacturers is higher with metals. And with metals, in most cases, you have a lot of post processing work, so you need additional equipment. You can’t just take the part off the machine and have it be the final part, or remove the soluble material. It’s actual post-processing work, CNC work, and finishing processes that need to take place.”
Making the Business Case for Additive Manufacturing
While 3D printing is widely seen as a “very cool technology,” Stratasys Direct Manufacturing believes it’s time for the industry to move forward by starting to change the conversation around additive manufacturing from one that emphasizes its technical benefits to one that focuses on its overall business value. For example, Bartel said that companies can realize significant business value by combining multiple parts—say, five or ten parts that were traditionally made by conventional manufacturing methods—into one piece. To the extent that they can consolidate parts, companies can save considerable material and assembly costs while also achieving benefits associated with reduced part weight.
“We can make some very cool, complex shapes and parts, and it’s a lot of fun,” Bartel said. “But there’s a real commercial value to the technology, and when you get down to purchasing and the procurement, and the higher level executives, the conversation about doing more in additive has to come down to the return on investment (ROI). If you’re going to be replacing an existing part, there has to be a payback on that. So we’re trying to change the conversation from ‘Yes, that’s a really cool part, a really cool technology,’ to ‘Hey, there’s a real business value in what the technology can deliver.’
But how can companies go about determining the business value that additive manufacturing holds for them? Data analytics, already being used in manufacturing applications to interpret machine data and minimize downtime, can be a powerful tool.
An emerging provider of additive manufacturing analytics is Senvol, a New York City-based firm that focuses on quantifying the business implications of adopting additive manufacturing. The company’s offering includes the Senvol Algorithm, a proprietary algorithm that design engineers can use to determine which parts can be made more cost-effectively via additive manufacturing versus by conventional processes. According to Senvol Co-President Annie Wang, the company’s clients include Fortune 500 manufacturers, government agencies, and companies in the additive manufacturing ecosystem, such as machine manufacturers or material providers.
“We look at everything as a combination of what is economically viable and what is technically feasible, so it’s a combination of not just engineering or technical specs, but also ‘Does it make business sense to do it?’ said Wang in a phone interview. “And if you find something that can bridge the gap between business and engineering, then that’s where you can find business profit in making that decision.”
When Senvol started almost three years ago, interest in 3D printing was exploding. Wang and co-founder Zach Simkin noticed that although a great deal of engineering talent was focused on 3D printing, there appeared to be a need for more business talent to focus on the commercial feasibility, or potential profitability, of the technology. As a result, many companies were very interested in additive, but were having a very difficult time evaluating the economic viability of adopting additive manufacturing, she said.
“People were very focused on ‘What can you make?’ but they weren’t so focused on ‘If you can make it, should you really make it?’ said Wang. “And so that was kind of our starting point—combining ‘What can you make?’ with ‘What should you make?’ from a business point of view. We started by helping companies make the business case for choosing additive, and our first product was, essentially, the Senvol algorithm, which helps companies make the business decision. The Senvol Algorithm basically takes into account all costs—not just manufacturing costs, but also supply chain costs. So if you can take into account all of those costs, that will basically be a holistic business case for either adopting or not adopting additive.”
Senvol has identified seven supply chain scenarios that “tend to lend themselves well to additive manufacturing,” according to Wang, including parts that are expensive to manufacture; long lead times; high inventory costs; and improved functionality, among others. “If a part falls into one or more of these scenarios, it may be cost-effective to produce via additive manufacturing and is a candidate for further evaluation,” wrote Simkin and Wang in “Cost-Benefit Analyses,” a piece they contributed to Wohlers Report 2015. “If a part does not fall into any of these scenarios, the part almost certainly will not be cost-effective for additive manufacturing, given the current state of additive manufacturing technology.”
Data for Design Engineers
In addition to offering analytics and consulting, Senvol develops information tools for additive manufacturing that include the Senvol Database, a 3D printing database of more than 1,000 industrial additive manufacturing machine and material entries. Users can search the database by more than 30 fields, including machine build size, machine price, material type, and material tensile strength.
Wang said that design engineers can use Senvol’s analytics and database to advantage in a number of ways. For example, an engineer might use the Senvol database to look for the appropriate machine or material[s].
“Design engineers already use the database a lot, especially on the materials side,” she said. “Let’s say they have a certain design that they’ve already designed for a part that already exists, and let’s say they know that they want to make that part in Inconel 718. They can then go to the database and say, ‘Okay, what are all the Inconel 718 materials that are available to me in additive manufacturing, and what are those material properties?’
“We also have some design engineers who look at the materials section in a different way. They’ll say, ‘This is the range of tensile strengths that I’m looking at, or hardness that I’m looking at, or Young’s modulus that I’m looking at,’ and they put that in, and it filters through all the materials and tells you which materials fit that description. So you don’t have to look at it by material type; you could really look at it property by property.
Stratasys Direct Manufacturing’s survey asked respondents whether they expect their company’s in-house 3D printing production to increase, decrease, or stay the same over the next 3 years. The survey asked the same question relative to outsourced 3D printing production. Graphic courtesy of Stratasys Direct Manufacturing
“The other thing is that after they’ve found the right material, the design engineer can also very quickly look at and see what machines are available. So what machines work with those materials that they’re looking at? And if they wanted to get a part made, they could call up a service bureau and specifically ask, ‘Do you have this machine? Do you have this material?’ and be able to get test parts made.
“On the costing side, the design engineer can look at the framework that we set up for estimating cost, and try to use that to figure out what would be the cost of making that part using additive.”
Creating Design Rules for Additive Manufacturing
Senvol is one of several organizations recently awarded a grant for the America Makes project, ‘A Design Guidance System for Additive Manufacturing. ’ The project, which also enlists the aid of Georgia Institute of Technology, Siemens Corporate Technology, Lockheed Martin, MSC, and GKN Aerospace, among others, seeks to address gaps and deficiencies that have been identified in the manufacturing design-to-print workflow.
“It’s a really big challenge and we’re really excited about the project,” Wang told D2P. “In additive manufacturing, the design rules are very different from conventional manufacturing. An engineer who’s designing something that’s meant to be machined, or injection molded, or cast would have an inherent understanding of what they need to be aware of. For example, if you’re designing something for machining, you’re thinking about, ‘How many faces am I machining, where am I going to put the jigs?’ et cetera.
“But for additive, the design rules are just completely different. And it’s not just different because it’s additive, but it’s also very different depending on what machine and what process you use. So the rules for SLA, or stereolithography, also known as photopolymerization, are going to be totally different from powder bed fusion, also known as SLS, or selective laser sintering.
“Because the design rules are so different because it’s additive, and they’re so different because each process has its own kind of design rules, it’s very hard for people to learn that very quickly. So design engineers need to be re-educated, or educated in a different way, if they want to be designing for additive. And right now, unfortunately, a lot of the design rules are still kind of ‘black magic.’ It’s by experience only, and so if you have experience operating the machines, or looking at parts that come out of the machines, then you have a good sense of what they are, but, unfortunately, because additive is still pretty young, we haven’t gotten to a point where we’re codifying that knowledge and making it available for all designers, unlike some of the conventional manufacturing processes, where it’s very well understood.”
The America Makes project takes several important “baby steps” toward achieving design rules for additive manufacturing, Wang said. Participants are currently working on a selection tool, which, based on the design of a part, will help the designer automatically narrow down the list of machines and materials that they should be looking at. If a designer inputs certain values relating to the geometry of the part, the database should be able to say, for example, “If you want a minimum wall thickness of 1 millimeter, then these are the materials that make sense, and these are the materials that don’t make sense,” she said.
“So that’s one thing we’re going to be working on—basically, based on the design, how do you narrow down very quickly and automatically, the list of machines and materials that you should be looking at?” said Wang. “And then, number two, there’s going to be a very simplified costing tool in there as well. So again, based on design, it’s going to help you cost out how much that part is going to cost to make.”
Learning to Think Differently About Design Tools
Scott Borduin is Autodesk’s group chief technology officer for design, lifecycle, and simulation products. In his keynote presentation at the TechConnect World Innovation Conference and Expo in Washington, D.C., earlier this summer, Borduin called 3D printing “a very interesting technology” that poses interesting challenges for industry going forward, particularly in getting engineers and designers to think differently about design. He pointed to two presentation slides of uniquely designed products—one of a heat exchanger and the other, a chair—as examples of 3D printed products that were designed using specialized software and which could not have been made by any other method.
The heat exchanger design, accomplished using optimization software, is about two thirds the size and “half the weight of the equivalent performing design that was made using more conventional techniques earlier,” Borduin said.” When you take a good look at that, you would think none of that would have come straight out of the mind of a designer, right? I mean, that had to be done with software.”
This heat exchanger, 3D printed in metal, was created with generative design using Autodesk’s Within software. Photo courtesy of Autodesk, Inc.
An even more extreme example, he said, is the chair design, completed using cloud based, multi-objective optimization software running with genetic algorithms to seed it. He called the chair “amazingly light and rigid and, once again, something that would never come straight out of the mind of a designer.”
“If you do an advanced circuit board or integrated circuit, nobody lays out every one of those traces manually; that’s all done by software when you put in the parameters,” Borduin explained. “But in the physical world, people aren’t used to that yet. So we show designs like this to an aerospace engineer and they freak out because they’re used to having intuition, at least, about where the stresses and strains are, and how things flow, and all that sort of stuff. You can’t do that now; you have to get to the point where you actually trust the tools.”
Getting to the point of trusting the design tools for additive manufacturing doesn’t figure to be easy. Borduin sees it as a challenge for the educational system, as well as the current practice of engineering and design. “If we’re going to actually train our new engineers and designers to use these kinds of tools as calculators of form, and have them think at a higher level of abstraction about what functions they’re trying to achieve, and how to make sure that the software is doing the right things, that’s going to take some very different thinking,” he said.
It’s also going to take some more experience in design for additive manufacturing, an asset that’s lacking among members of the current workforce, according to Terry Wohlers. It’s also not a trivial thing to learn, he added. “It’s like anything: You can’t learn to design for injection molding in one week or one month, or even one year,” he said, “and the same is true with this. In some ways, it might even be more difficult because there are so many additive manufacturing processes.”
A Winning Formula for Race Cars
Brian Levy, a design engineer with Joe Gibbs Racing (JGR), manages the NASCAR group’s in-house additive manufacturing systems and works with JGR’s other design engineers to help them design parts for additive manufacturing. While it primarily supports the group’s four full time teams in the NASCAR Sprint Cup series, JGR’s engineering department stays extremely busy throughout the 38-week Sprint Cup season, as it also assists JGR’s three Xfinity teams and motocross team.
On any given week, the race team is preparing eight race cars—a primary car and a backup car for each of the four Sprint Cup teams—to go to the track. But it’s also disassembling and inspecting eight more race cars that just came back from the track, while also working to prepare another eight race cars that are getting ready to go to the track for the next weekend’s event. At the same time, the engineering department is constantly working to keep up with rule changes, as well as issues that occurred at the track, and trying to work on new developments to keep the cars competitive, Levy said at the Big M in Detroit this summer.
“One of the hardest things in motorsports is to stay competitive on a week-to-week basis,” said Levy, speaking at a private event hosted by Stratasys at the Big M in June. “While all of this is going on, we’re constantly finding gains in performance, and the key for us is to try and get those gains on the cars as fast as possible. We have cars that are constantly being disassembled, constantly being put together, so the quicker we can get those gains on our cars that are getting assembled right now, the quicker we can reap the benefits of those gains that we find in performance. So that’s of course where additive manufacturing comes into play.”
Joe Gibbs Racing has been using additive manufacturing for about ten years, thanks primarily to the support of Stratasys, Levy said. At the beginning, the team used it mostly for prototyping—checking form, fit, and function of parts, making sure that its designs fit where they were supposed to be, and that they solved the problems that the team was trying to solve. “We made some jigs and fixtures and we made some end use parts, but certainly not as much as we were doing with the prototyping,” Levy said.
Today, the team still does a lot of prototyping, but as the technology has developed, JGR now uses additive manufacturing to make a significantly higher percentage of jigs, fixtures, and end use parts. “These are parts that end up on a car every single week, not just parts that fill in on the car,” Levy noted. The team uses three Fused Deposition Modeling (FDM) systems, all capable of making a variety of prototypes, tooling, fixtures, and end use parts that actually go on the cars. They include a new Fortus 450 machine that offers a large build envelope; an Objet Connex 3 that’s well suited for making smaller end use parts with higher resolution; and a Dimension 1200 machine that Levy says the team uses to “supplement the workload of the Fortus system.”
A 3D printed chair that was generatively designed by the design studio The Living. Photo courtesy of Autodesk, Inc.
Fixtures, Tooling, and Real Production Parts
Levy outlined a few cases in which additive manufacturing brings value to the race team’s efforts to react quickly to design changes and build performance gains into their cars. In one case, the team uses either its Fortus or Dimension system to quickly build fixtures that accurately position chassis tubes where they’re required to be, helping the chassis to pass NASCAR inspection and enabling the assembly process to move along without interruption.
Each NASCAR chassis has close to 100 round or rectangular tubes on it, Levy said, and every one of them is critical in some way. Many of the tubes are subject to NASCAR mandates for size, shape, or location, with tolerances that could be “an eighth of an inch or less,” he said. Even if the tube isn’t mandated by NASCAR, it needs to be fixtured correctly because either a suspension component, one of the driver controls, or the steering wheel could be bolted to it.
“With the pace that we move at, the rate that we’re constantly building cars and sending cars to the racetrack, we really don’t have time for cars to fail inspection,” Levy said. “We need to be sure that every tube is on that car exactly where we want it to be so that it passes inspection the first time, and we can keep the assembly process moving along. So being able to fixture everything properly, adapt to rule changes, adapt to design changes, is really where additive manufacturing comes into play here and helps us out in this process.”
If a design change needs to be made, additive manufacturing enables the team to make new fixtures in a day or two. “We can implement a design change on cars that we’re going to start building either tomorrow or the next day or next week, and nothing gets slowed down,” Levy said. “From the time that a design change is implemented, we can have new parts made within a day or two, which is ultimately what we need to do to stay competitive.”
The race team also uses its Fortus and Dimension machines to build tooling for composite parts, such as a brake duct used for cooling front brake calipers and brake rotors. One of the challenges in designing parts for racecars, Levy said, is finding sufficient space to package them. “You can see that this brake duct has to squeeze in between the chassis and a spring on one side, and a brake caliper on the other side, and there isn’t a lot of room to maneuver a brake duct in there,” he said referring to a presentation slide. “So a lot of times, we end up with very complex and organic looking parts that, if we had to produce the tooling for these parts using conventional milling operations, we would need very large, expensive, complex machines—5-axis or 9-axis machines, and it would also take a week to program and to produce, and we just don’t have that time. Like I said earlier, we’re constantly finding gains in performance, and being able to make these changes and get them on the car as quickly as possible is the name of the game.”
The race team has two options: either use the FDM part as a form for doing the carbon layup right on top of it, or use the FDM part for producing a set of female molds, and do the carbon layup on the inside of that. It depends on a number of factors, Levy said, including the complexity of the part and the surface finish they’re after. Because of the complex geometry of the brake ducts, the team typically uses the FDM parts to make female molds, and then does the carbon layup.
“By using additive manufacturing, when we find a gain in brake duct design, we can produce the tooling for it, we can then produce the finished carbon part, and get it on the car as soon as possible, and we’ve done this in less than a week’s time,” Levy said. “So if on Monday, our race teams come back from the track and they want something different for their brake cooling package the next week, we can make that happen before the truck leaves on Thursday, which is ultimately what they’re after. If we tell them they have to wait two weeks or three weeks for this improved part to end up on the car, they’re not going to be happy about that.”
In addition to producing chassis fixtures and tooling for composite parts, the Joe Gibbs Racing team is using additive manufacturing to produce end use parts, such as battery case covers and dashboard inserts that allow the driver to view different configurations of gages and displays during the race. As with the chassis tube fixtures and tooling, the team’s use of additive manufacturing for end use parts provides gains in manufacturing efficiency that translate into significant time and cost savings.
Building the battery case covers on the Connex 3 allows the team to include detailed features—such as passageways for wires, and connectors that tie the battery into the car’s electrical system—that it would not have been able to produce either on its larger Fortus system or via conventional milling operations. The dashboard inserts, on the other hand, can be built on either the Fortus, the Dimension, or the Connex machine.
“Similarly to the brake ducts or the battery covers, we try to keep as many of these [dashboard inserts] in inventory as possible, but if a race team comes to us on Monday and asks for a different configuration, if we don’t have that in stock, or if it’s something new that we haven’t built before, we can design it in a day or two,” Levy said. “We can then have it printed the next day, and have it installed on a car so that when the truck leaves on Thursday to go to the race track, the driver has exactly what he wants.”