SME Logo

2014 Design for Direct Digital Manufacturing Competition Winners

Share this

(DEARBORN, Mich., June 23, 2014) — SME is happy to announce the winning designers of its 2014 Design for Direct Digital Manufacturing Competition — Darren Walker and Scottie Waldhaus from Western Illinois University in Macomb, Illinois. Their winning design — a truck — featured nine pieces to collect and assemble from RAPID 2014 exhibitors American Precision Prototyping LLC; Cideas; EnvisionTEC; Harvest Technologies; Materialise; Met-L-Flo; rapid prototype + manufacturing; Stratasys; and Roush Manufacturing.

2014 DDM Competition DesignFor the 2014 DDM Competition, student designers were asked to utilize additive manufacturing for the creation of a nine-piece car body. The winning design was distributed by show-floor exhibitors as pieces for the RAPID Challenge Puzzle. Ultimately, the result of the challenge is a functional mechanism or assembly with interlocking parts. The geometry of the design had to be defined within a 3D CAD system capable of producing robust STL files. The deliverable had to include a complete bill of material/parts list where file transfer enables reproduction of the nine-piece car body.

This yearly competition is sponsored by the Direct Digital Manufacturing Tech Group, which is part of SME's Rapid Technologies & Additive Manufacturing Community

2014 DDM Competition Winners
2014 Design for Direct Digital Manufacturing Competition winners Darren Walker (left)
and Scottie Waldhaus (right) from Western Illinois University pictured with Rafael
Obregon (middle), assistant professor of engineering technology at Western Illinois.

Design Details

Processes and Materials Used
The great benefit of using direct digital manufacturing (DDM) is the flexibility of the process. Machines can produce an almost infinite amount of different parts, tools, toys and so on — all while being able to produce them with a diverse amount of materials using simple additive process equipment, such as a Makerbot Replicator X2. It is possible to 3D print in multiple colors and materials (like ABS plastic), or depending on the hardware, with biodegradable plastics, silicones, chocolate and even wood.

There’s a lot of different materials that serve different functions when used in your models. The flexibility of your machines isn’t only in its access to a large number of materials, but also in the programs used to generate these models, and most programs can export into a standard STL file type that most 3D printers need to print.

While being flexible, DDM also allows you to print in small batches, which can gain you more customers who only need one object printed out, just so they can show others. Being able to look at a 3D model on screen before any material has been used, adjust it to your liking and then print it, saves a lot of man hours and waste material when developing prototypes or short-run production.

Environmental Impact Analysis
While the world is slowly turning green, as far as recycling and renewable energy goes, the machines used for DDM run off less energy, and the material used in most of the filaments used in its machines can be recycled. There is even a machine that anyone can buy — called Filabot — that lets you recycle ABS plastics and produce your new filament. With such a machine, any failure productions may be crushed and remelted all in the same room. Companies spend thousands of dollars sending bad molded plastics back to another company to get ground down; that plastic is no longer virgin plastic and those companies can't reuse that old plastic in their products very often.

With landfills overflowing a green solution to production is needed in today’s environment. Oil prices are skyrocketing, which effects the plastic molding industry. Finding better ways to recycle used materials is important and can be cost-effective because other companies do not even want it and pay to get rid of them most of the time.

The energy costs of these machines can run off solar panels and are very efficient compared to the typical industrial machines in factories across the world. The electrical bill savings would add up quickly. The benefits of making a company green not only stop at saving money, it can be advertised to attract more environmental consumers looking for greener products.

The technology allows for producing test prototype, that if not satisfactory, can be recycled and the material reused.

Cost-Benefit Analysis
Assuming that the model is produced out of 90 in3 for the design, although that could be scaled up or down, a simple cost-benefit analysis (considering the cost of a spool of ABS plastic being $50 per pound, yielding a total resulting volume of about 40,000 in3 of prototypes), and estimating that the project utilizes just one machines, total use would be only about 15% of that volume due to the hollow honeycomb pattern the firmware employs to save material and make the model lighter. Using rafts, and possibly supports will level the utilization to 20% doubling the volume use to about 180 in3. Total cost per unit, compared to material cost, will translate into a part cost of 23 cents per part.

Considering a $2,700 cost for the machine, and $50 per spool (about 220 products), and a profit margin of 31% (sell price of about 30 cents), 12,000 complete assemblies will need to be produced to break even.