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Seeing Is Believing

Wed, 11/21/2007 - 7:07am
Jeff Reinke

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The role of 3-D printers in product design and development continues to increase.

By Jeff Reinke, Editorial Director

Sculpture created using 3D prototyping

All the parts pictured in this article were produced with a 3-D printer to help demonstrate the added features, such as color, and detail that can now be realized with this prototyping technology.

They say that a picture is worth a thousand words, which must place the value of a physical prototype at a level where even Webster would be envious. It's no secret that the use of 3-D printer-authored prototypes has grown tremendously in recent years, but the extent of this growth, and the reasons for it, might surprise you.
Kirby Morgan Dive Systems Product Development provides underwater breathing equipmen

In Depth Prototyping

"At the extreme depths many of our customers are required to work, there is no room for error," says Pete Ryan, senior engineer, Kirby Morgan Dive Systems Product Development. "Divers require us to provide safe, reliable, underwater breathing equipment, sometimes tailored specifically to their needs."

With a rich history of providing cutting edge equipment, Kirby Morgan Dive Systems thrives on delivering innovative, fail-safe products to the diving community. From commercial diving helmets to scuba regulators, Kirby Morgan looks to accommodate unique diving applications and extreme environments.

The company receives time-sensitive requests from a variety of organizations, requiring rapid product design and re-design, which can be a major challenge. Designs must be thoroughly tested to ensure the highest levels of quality and reliability, regardless of deadline. "Some of our new product designs and improvements require us to move ahead pretty quickly," Ryan states. "The designs we create often require a lot of adjustments, handwork and multiple 3D models before a final version can been approved."

For years, Kirby Morgan outsourced the production of 3D models to service bureaus, but the shipping and turnaround time needed to produce these prototypes made it difficult to move through the design phase quickly and efficiently. So the company was in search of a more time-efficient process to build accurate, cost-effective 3D models.

By bringing 3D printing capabilities in-house, they sought to cut model production time and obtain complete control over the product design process. "Dimension was the obvious choice for us," states Ryan. "The durability and accuracy of the models produced meets our standards, and the purchase price was highly competitive."

When the U.S. Military requested a modified regulator with a higher level of breathing performance than the standard unit Kirby Morgan was producing, the Dimension printer was put to the test. The design team needed to build and test two new components for the regulator, and the military requested delivery as soon as possible.

With the Dimension 3D printer, Kirby Morgan was able to maintain its high standard of quality while meeting the U.S. Military's request for fast delivery. Several models were created, evaluated, modified, finished and delivered in just one week - cutting weeks off the completion time required when outsourcing 3D model production. The printer has also increased the production team's efficiency by enabling them to cut model production and review times.

"We now have a much higher level of control over the timing of the product design phase," Ryan states. "Since adding the Dimension 3D printer, we have averaged a 50 percent reduction in time spent on product design."

Wohler's and Associates estimates that Stratasys, Z Corp., 3D Systems, Objet Geometries, EnvisionTec and Soldidimension (all leading 3-D printer providers) saw 2005 sales figures for their machines reach an estimated $100.2 million, up from the $74 million sold in 2004. In unit sales, 2,528 3-D printers were sold in 2005, up 29.8 percent from 2004. It's estimated that these types of machines accounted for 70 percent of all additive system sales in 2005, which would also encompass SLA (stereolithography), FDM (fused disposition modeling) and other prototyping methodologies that will be discussed further on page 40 of this issue. If the current demand for this technology continues at its current pace, an estimated 15,000 3-D printers are expected to be sold annually by 2010.

Just to review, 3-D printers operate similarly to an ink jet printer, as its roller travels back and forth dispensing material and binder in the manner directed by a CAD file in building up a part or prototype layer by layer. The simplicity of its core functionality is one of the reasons behind the usage growth. Another is its price, as 3-D printers are comparatively inexpensive when held up to other types of additive approaches. Most models now run under $50,000, with an FDM machine, for instance, costing hundreds of thousands of dollars.Getting back to the simplicity of these machines, their design also lends well in embracing the office environment, as opposed to the manufacturing floor. So current technology, with enhanced material usage, smaller footprint options and quieter operation, means these machines can be in the same vicinity as the design engineer using them.

The Boxer: A 3D printed prototype
Todd Grimm, president of T.A. Grimm & Associates, a rapid prototyping consulting firm, offers this perspective on those types of 3-D printer features. "Not only does self-service prototyping provide additional design change power, but the user is no longer dependent on the model or job shop for producing their prototype. It shortens the process and probably diminishes prototyping avoidance. Essentially, there are no more barriers involved in making a better decision. I'd compare it to printing a rough draft of a report - you may do it several times on your desktop printer, but wouldn't even consider going to Kinko's for a draft."


Valuable Player

Price and simplicity are only some of the core 3-D printer values, but they mesh well with the quicker turnaround and precision produced by these machines in providing a value-added option. Basically, there are more accurate ways to create a prototype, but some take longer and consume more floor space, and all cost more. Additionally, although there are some limitations when it comes to material choice and part size with a 3-D printer, they do allow for adding greater details and come out of the machine needing very little, if any, finishing work. This will depend on the type of model. Z Corp's units also allow for adding color.

The quick turnaround and in-house control of these printers have been key to their growth, as this naturally aids in gaining more feedback, more quickly - shortening the design and development process. In many instances, the accuracy of these units has also helped in identifying and eliminating unnecessary or inaccurate tooling, as well as other production-related issues.

3D prototype with color capabilities
Dimension's Jon Cobb offers insight on another core benefit. "Many companies want to enhance their CAD software purchase, and 3-D printing allows the designer to quickly see their designs right at the desktop. The designer can look at the design, review the model with the entire design team, company management or even manufacturing and marketing in receiving feedback on all aspects of it."

Key to speeding these development times are the types of materials that can be used in building a prototype. Typically, 3-D printers will use some sort of high-performance plastic like acrylonitrile butadiene styrene (ABS), but more is being done in the areas of rubber and metal. "The market wants durable models produced in a variety of plastics or metals," adds Cobb. Dimension's Elite model features ABSplus, an updated ABS that is, on average, 40 percent stronger than standard ABS."

"The types of features that are being examined by Objet's technical team," adds Stephanie Checchi of Objet, "are focused on the mechanical properties of different materials. There is a huge amount of research and development being done to examine acrylic photopolymers and elastomers. This is a significant growth opportunity because it enables various combinations of materials to be altered in printing prototypes with different mechanical properties.

"For instance, if you need to print a tire around a wheel you can print the rubber-like material along with the hard acrylic wheel inside. With new technology being developed, this process will soon be available, eliminating the need to print two separate parts and then assemble them."This matrix of digital materials opens the door to many applications and material capabilities. It is virtually an endless number that can be combined, which allows for many different designs to be produced."

Z Corp.'s Kevin Lach adds, "We also are investing heavily in the development of new materials that will allow our customers to vary model properties like strength, color and flexibility to match the application. Versatility is important. Our customers know the hardware they buy today will get better with the materials we introduce tomorrow."

A big difference amongst the market's collection of printers and methodologies is layer thickness, or the amount of material being applied with each pass. This will be impacted by the type of material used, which will depend upon the project, the amount of time available for producing a finished prototype, and other project-related factors. In any case, looking at the type of material or materials that can be used by a given machine will be a vital component of the purchasing process, as will envelope size.

Lach explains, "Build size is certainly a factor in selecting a 3D printer. For example, footwear companies typically choose our largest printer (build size of 10" x 14" x 8") because it is capable of producing multiple copies of a full size shoe sole simultaneously. However, equally important considerations are throughput (how many models, and how often), color versus monochrome, user type (automated printers are better suited to novice users) resolution (higher resolution machines produce better graphics), and of course, price." Typical envelope sizes seem to range from about 650 to 2,600 cubic inches.

Cobb suggests that, "companies review their typical part sizes and base a decision on what size system can handle 80 percent or more of their typical parts, utilizing a single build." This would not include parts that are often "cut" and printed separately before being glued together in forming the final prototype.

It's A Small World

As is the trend with a multitude of other technologies, the next step for 3-D printers seems to be focused on decreasing the unit's overall footprint. With their new V-Flash™ Desktop Modeler (more product-specific information is available on page 6), 3D Systems has unveiled a unit that will physically fit on a desk and cost under $10,000. 3D's foray into the printer market comes after establishing a name for its selective laser sintering (SLS) machines.

"Desktop modeling enables a more modern process known as Iterative Prototyping - the integration of frequent prototypes into the design workflow," explains Nick Carter. "The technology that makes desktop modeling possible is actually an evolution of stereolithography. While the fundamental principal is the same, there are several key differences that address the speed and efficiency of the process. This new technology is called Film Transfer Imaging (FTI) and it is proprietary to 3D Systems. Both FTI and stereolithography cure a photopolymer layer upon layer to form a solid model. However, unlike the lasers found in traditional stereolithography, FTI uses a broader ultraviolet source to cure each layer in less time. The process creates stereolithography-like parts much faster, while maintaining the part's integrity and surface aesthetics."

3D also feels their new unit helps improve material consumption efficiency through greater precision, the recycling of unused material, and the use of fewer supports during the building process.

Looking ahead, smaller footprints will not be the only factor driving 3-D printer growth. Additionally, new applications should play a key role in the broader acceptance of this technology. "The first application for 3D printers was prototyping because mechanical design software made printable 3D data so available," states Lach. "What is exciting is the rate at which 3D data is emerging in every industry from architecture and electronic games to 3D mapping and medicine. Each of these applications will require a 3D output device to produce building concepts, entertainment avatars, 3D maps from geospatial data and physical models from CT Scan data. We see applications beyond prototyping as very promising."

Additionally, industry experts see a growing demand for 3-D printers in producing models that can be used for tooling and production fixtures, as well as in educational settings. Many companies also use 3-D printers in conjunction with SLA or FDM methodologies in producing prototypes, or for rapid manufacturing applications.

At the end of the day, 3-D printers are one of multiple options for producing prototypes. The key in deciding how or if to implement this technology will stem from assessing where your priorities are in terms of cost, time, precision and material usage.

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