How do you shop for a rapid prototyping service bureau? First and foremost, says Charles Overy of LGM, a Minturn, CO-based provider of visualization and modeling solutions.
"You need to be honest about what you know, what you don't know, what you want to learn, and the timeframe you have to learn it in," he says.
"We can do a simple 3D print if someone brings us an STL file," Overy continues. "But if you've got a SketchUp drawing and you need a model to put in front of your client in two weeks, that's a whole different conversation."
Maybe this isn't your first time around the block. "If you're using SolidWorks," says Overy, "and you know you want STL, and you've had experience with STL printing, and you know that the STL file you're generating is solid, and you're printing it at 1:1 scale, and you don't need help with draft angles then you can shop on price. If not, and if you don't have time to learn about 3D printing, look for a specialty bureau that works in your area of need in order to fill in some of the blanks."
Specific industry knowledge can save you time and money, Overy says: "You may find that we can save you substantial money over an aggregator or another bureau, simply because we know the specifics of the industry." LGM primarily produces architectural models, but the same can apply to other industries.
Overy suggests looking at a candidate bureau's website, to determine whether its body of work is applicable to your project. If they have the same stock samples as dozens of other sites, you might win on price, but lose on knowledge, support and value-added services.
That last factor is a dealmaker for LGM, Overy notes: "About 50% of our revenues do'nt come from 3D printing; they come from value-added services related to taking the [customer's] data and getting it ready to 3D print."
Know What You Want
What are you trying to accomplish? Do you really need a metal part, or can you live with a prototype that looks like metal? Does it need to live and work in the real world, or just look pretty at a trade show?
Do you have a design review next week? Then speed is your primary concern. Or maybe you need a prototype that looks and functions just like a real product. In that case, you'll need to go down a different path.
"Sometimes we give a customer a price and they go into sticker shock," says Chuck Alexander of Solid Concepts, a rapid prototyping service provider. "When we dig a little deeper, we find out they don't need a cosmetic, functioning part; they just need something to pass around the table. The more detail you can provide, the easier it is for a service bureau to recommend the right thing."
Dare to Compare
There are a lot of rapid prototyping service bureaus out there. Shop around. "Don't stop at the first place," advises Michael Siemer of IMDS, a medical device outsourcing company. "Talk to at least three different companies."
Just a quick conversation, he says, will usually give you a good feel for whether the company has the experience you need: "Are they trying to help you, or are they just trying to sell you? Some companies just want to make the sale, and you don't typically find that out until you get your parts back."
Siemer says it's also important to find out whether a candidate bureau can back up its recommendation with good technical direction. And local, face-to-face service is key.
"If I had a choice between two different companies and one would save me 10%, but was located in another state, I would pick the local company," he adds. "When I get my part and it's not exactly what I want, I can get help more effectively."
"After all, when things go wrong," says Siemer, it's nice to have a "throat to choke."
Realize AM's Limitations
While metal additive manufacturing (AM) is a hot topic, there are more limits with metal AM than plastic, according to Siemer. It's also more expensive.
"People think, 'I can spend $300 on a plastic prototype, maybe metal's just a little more.' It's not just a little more," he says, noting that metal parts and prototypes can easily cost five to 10 times as much as plastic. "Some people believe that because it's 3D printing, it can build whatever you draw. But additive manufacturing has limitations, just as with any manufacturing process. It has a lot more design freedom, but it's not perfect."
Do you need a working part with a 0.010-in. living hinge? It's probably not going to happen, Seimer says: "That's one of the reasons to go to a service bureau, to get basic education about what additive manufacturing can and cannot do."
A Matter of Size
The size of your part is also a factor in choosing a service bureau.
"Something large like a car bumper typically has to be built in multiple pieces and assembled," explains Terry Wohlers of Wohlers Associates, a consulting firm specializing in 3D printing. "These are more complex projects. You want the pieces to lock together, almost like a jigsaw puzzle."
With that in mind, you want a service bureau that has the tools, skills and experience to pull it off. Another factor that is sometimes overlooked is the downstream processes, Wohlers says.
"It's one thing to submit a file and have parts built, but it's a 'whole nuther thing' to process those parts--not only to knock the supports off or remove the excess powder, but to really clean them up and prepare them for whatever application you require," he adds. "If you want to present those parts at a show, they have to be polished up nicely, and typically painted or coated. Not everyone has those capabilities. Some people just 'strip-and-ship;' they clean the parts up and ship them out."
You might need something a bit more refined, but that can take time, he says. "You can coat these parts so you can't tell how they were manufactured. They look injection molded. They look like finished products," Wohlers says. "But it takes a lot of expertise to get to that level of finish."
No service bureau can do everything, he points out. Processes like chroming might have to be outsourced, which will add more time. But do you really care about the production speed? Maybe you can wait two or three weeks for your prototype. For a rapid prototyping bureau, two weeks isn't fast; it's slow. If you're willing to wait a little longer, it can sometimes save you money.
Quality, Service and Information
Another important consideration is a service bureau's quality control system. "Solid Concepts is a manufacturing company," notes Alexander, "so we treat [rapid prototyping] that way. All of our shops have ISO certifications. In lieu of those certifications, you have to start to dig deeper. How do they control their processes? How do they know they're not contaminating one material with another?"
The key, he says, is to look for a company that's focused on service. "Plenty of people out there will build parts, but are they a service organization? That's something you want to focus on, especially if you're a new user.
"The rapid prototyping industry--especially additive manufacturing--changes pretty quickly," Alexander adds. "If you're a design or manufacturing engineer, it's usually not your job to stay up to date on all this stuff. It is our job."
A Diversity of Processes
The experts agree that ideally, your bureau should be a diverse one.
"Make sure you get the right solution, not just the process they have in-house," says IMDS' Siemer. If you go to a service bureau that only offers STL, for example, it's no surprise that that's probably what they're going to recommend. People sell what they have, so look for a service bureau with a range of manufacturing options.
And don't forget traditional methods, such as computer numerically controlled (CNC), laser jet cutting, water jet cutting or urethane casting techniques.
"The more a service bureau has to offer, the easier it is for you as a customer," Alexander concludes. "You don't have to work with multiple vendors."
Contributing Editor Mark Clarkson is DE's expert in visualization, computer animation, and graphics. His newest book is Photoshop Elements by Example. Visit him on the web at MarkClarkson.com or send e-mail about this article to DE-Editors@deskeng.com.