If you draw it, can you print it?

by Jean Thilmany, Contributing Editor

3D printing enables you to reduce part weight, raw material used and cut total energy used in production. But to truly take advantage of 3D printing, engineers need updated, intuitive, easy-to-learn CAD tools.

To keep pace with advances in 3D printing, CAD technology must move into the cloud, become easier to use, and be better able to support eccentric, not-yet-dreamed-of designs, say several design experts.

If CAD technology can evolve, in the not-too-distant future, everyday objects like your blender, electric toothbrush or even the engine within your automobile, will take the shape of nothing you’ve ever seen before, said Hod Lipson, a mechanical engineering professor and director of the Creative Machines Lab at Cornell University.

Lipson has written extensively about 3D printing and helped develop Fab@Home, inexpensive 3D printers. He published the paper “Is CAD Keeping Up?” in the December 2014 edition of the journal 3D Printing and Additive Manufacturing.

That question—is CAD keeping up with 3D printing—is one he asks himself as additive manufacturing continues to gain popularity. Most 3D printers take their printing instructions from 3D CAD files. Because the 3D printer receives its instructions from CAD files, the printers are limited in the shapes they print that those CAD systems generate, Lipson said.

The 3D printers themselves can print objects with geometries as yet unimagined. Any shape, no matter how twisting, undulating or odd, is fair game, he said. So the future could feasibly resemble a Dr. Seuss-style landscape rather than boxy squares of today’s laptops, ovens and refrigerators.

But CAD software only allows for designers to work with recognized geometries: circles and ovals, squares and rectangles, and so on.

fusion360-keyshot
Products will be designed in a more collaborative way, moving through 3D modeling, then on to simulate, analyze and test, and then on to integrated CAM or 3D printing.

Guided by the design file, a 3D printer lays down layer after layer of a material to print an object in three dimensions. Some of today’s printers and materials can create objects that can immediately be used, doing away with the need for another manufacturing step, Lipson said.

While CAD continues to evolve, changes to that software are mainly seen in the way engineers interact with the software rather than in the shapes and designs they can create with the software.

Take, for example, sketching applications that allow engineers to draw their designs as they would on paper, rather than pulling or piecing together existing geometries. Catchbook, from Siemens PLM, is one example. While these aren’t CAD applications, in some cases, such as with Catchbook, these designs can serve as precursors to CAD designs.

“It’s freehand ink, not just dead ink on a page, so you can edit and manipulate it, can erase and insert images and share content with other people,” said Ken Hosch, director of strategy at Siemens PLM.

Other examples of freehand-drawing-style applications include SketchUp, Sketches and Drawing Pad. Though SketchUp can be used on a desktop, most of these drawing applications are intended for the tablet, with your finger or a stylus acting as the pencil.

But even these freehand design programs come with drawbacks that mean they can’t be used—yet—to print odd and eccentric shapes on a 3D printer.

The industrial drawing engine behind Catchbook, for instance, automatically turns the individual parts of a drawing into recognized geometries. If a Catchbook user sketches a lopsided circle, the engine creates a perfect circle, Hosch said.

What we need to see for the printed shapes of tomorrow to be possible, Lipson said, are programs that allow freehand drawings to be printed in 3D without the need to change drawings into recognizable geometrical shapes. If you can draw it, you can print it, he said.

What’s more, conventional CAD software imposes its own limitations on designers, who may not be able to think outside the “because it’s a computer it must resemble a box” box, Lipson said. So even as CAD changes, designer mentality may be slow to catch up.

Which is a particular lag at a time when 3D printing allows many advantages to large and small manufacturers, including the capability to build one-off and custom parts at remote locations, he added.

Another recent trend in 3D printing has been from printing prototypes to printing end-use parts, according to Terry Wohlers, president of Wohlers Associates, a Colorado-based additive manufacturing consulting firm.

Recently, for example, GE Aviation announced plans to include 3D-printed parts in its CFM Leap aircraft engine platform beginning in 2016. The engines, produced jointly by GE and partner Snecma, will include 19 3D-printed fuel nozzles in the combustion system.

Last May, printer manufacturer Stratasys announced that its printers had been used to produce more than 1,000 flight parts for the Airbus A350 XWB aircraft, delivered in December 2014. Similarly produced components are also included within in-service jetliners in the A300 and A310 family, according to Airbus.

Autodesk_Fusion360
The recently released Fusion 360, from Autodesk, is a CAD, CAM and CAE tool that exists in the cloud. It can be connected to have 3D printing capabilities.

The parts weigh 30 to 55% less than traditionally manufactured parts, reduce raw material used by 90% and cut total energy used in production by up to 90% compared to traditional methods, according to Peter Sander of Airbus’s Innovation Cell, which investigates and promotes emerging technologies.

But for these trends to continue, engineers need updated, intuitive, easy-to-learn CAD tools, Lipson said. And without them, it will be even harder for mainstream designers and consumers to fully adopt 3D printing, even as desktop printer prices drop, according to John Darlington, a computing professor at Imperial College, London.

“While there is little doubt 3D printing technologies will have a highly transformative effect in the coming decades, consumer adoption of these technologies still remains rather low,” Darlington and his colleagues wrote in an August 2015 paper in the Journal of Engineering and Technology Management.

“Making an object requires more than just a 3D printer and advanced knowledge of 3D modeling software,” the researchers wrote in the paper “Co-creation and User Innovation: The Role of Online 3D Printing Platforms.” Darlington fellow authors are Ludmila Striukova, senior research associate in the University College, London, school of management, and Thierry Rayna, a professor of economics at Novancia Business School of Paris.

One area in which 3D printing and CAD technologies are both moving forward are within the cloud. This tandem momentum will help small manufacturers take advantage of 3D printing, said Amy Bunszel, Autodesk VP of AutoCAD products.

3D printers, along with CAD software that exists “in the cloud” (that is, not on users’ networks but on remote servers into which they can tap), will allow for small-scale, custom manufacturing, Bunszel said. Because they don’t need to maintain expensive software and hardware in house, companies, small designers and hobbyists can quickly and easily design and print parts.

3D printers may not strictly exist within the cloud, but they could be—and often are today—housed at service bureaus, away from the engineer or manufacturer, but can still be used to print their files. Printed pieces can then be sent to the original engineer or manufacturer, or could be sent directly to a customer.

With access to 3D printers and to CAD programs in the cloud, engineers could also design a part and have it printed in small batches of many variations rather than manufacture parts—as is done today—using CAM files in a mass-produced, one-size-fits-all method, Lipson said. “That was not economically viable before,” he added.

Or, as Bunszel put it, “The cloud changes everything; mobile, social, everything.”

Her company, CAD-vendor Autodesk, recently released Fusion 360 a CAD, CAM and CAE tool that exists in the cloud.

“So it could be connected to have 3D printing capabilities. It connects your entire product development process,” Bunszel said. “You have 3D modeling capabilities, then can simulate, analyze and test, and then take into integrated CAM functionality or to 3D printing.”

Products in the future will be designed in a more collaborative way, she predicted. “People are designing things together with access to new techniques, like 3D printing, which are accessible to all of our customers, not just big manufacturers.”

The tools designers have used in the past need a refresh to be useful in the future, she added. The cloud offers an easier way to access and work with CAD technology, she said.

For his part, Lipson wants to see CAD and 3D printing technologies work together for a future in which engineers can create in 3D anything they can envision—and even shapes and objects that can’t be envisioned today. In other words, the computer of the future won’t be square in shape.

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Autodesk
www.Autodesk.com

Siemens PLM
www.plm.automation.siemens.com

Stratasys
www.Stratasys.com