Boulard Designs
Appearance Models from Weeks to Days!

Boulard Designs went from shop tools to CNC for faster,
more accurate crafting of appearance models for
GE® Appliances.

Case Study: Design Prototypes
February 2009, Appliance Magazine
















GE® designed its new tankless gas water heaters to provide continuous hot water on demand. The unit activates only when the user turns on the hot-water tap. It deactivates as soon as the demand for hot water ceases.

During the design process, GE® relied on Boulard Designs International (Louisville, KY, U.S.) for appearance models. Boulard Designs built models of the indoor and outdoor versions of the tankless water heater as well as models of the remote control.

















[above] Cooktop knob models being
produced on the CNC router.

Boulard developed the detailed design for the front panel assemblies, working with General Electric and a parts supplier. The company also machined the front panel for each model, as well as the cabinet the panel mounts to and the remote control.

Boulard Designs has long worked with GE® to provide models that are used during the design process to research consumer preferences. Parts that must be machined to very close tolerances include the door, grill, control panel, knobs, and handles. These parts are typically produced from RenShape modeling material, then sanded and painted.

In the past, the company usually constructed its designs using power tools such as routers and planers, and took about two weeks to build a typical model. More recently, it invested in a computer numerical control (CNC) router that automatically machines the models based on geometry generated in computer-aided design (CAD) software.

"CNC machining has reduced the time to produce a typical realistic model of a microwave front panel to less than two days," said Norman Boulard, president of Boulard Designs.

















[above] Norman Boulard's CNC router machines models based on CAD-generated geometry.

Machining versus Rapid Prototyping
The company ruled out other model-making approaches. Boulard said rapid-prototyping methods take time and the prototypes tend to be brittle and dimensionally unstable. This approach has size limitations as well. Another approach is to make models on CNC machines made for production capacities, but this too can be expensive and impose size limitations.

Recently, less expensive CNC machines with a large working area have been launched specifically for model and prototype

builders. These units produce precision parts from wood, plastics, and softer metals. Boulard looked into such machines, seeking a rugged, highly accurate machine with a large working area – and a price tag well under $40,000.

The machine that fits these specifications was from the RG series from Techno-Isel (New Hyde Park, NY, U.S.; www.technocnc.com). The frame of the unit is a single welded piece, designed so the unit will never get out of square or require alignment. It is constructed on a heavy steel ground stress-relieved base and includes a heavy-duty aluminum T-Slot table and ball screws on all three axes with closed-loop servo controls. The machines provide repeatability of 0.001 in., a resolution of 0.0002 in., and a maximum speed of 800 in. per minute.

















[above] Cooktop models being produced on the CNC router.

Boulard Designs now produces over 50% of its work on its RG Series 5950. Norman Boulard uses Virtual Gibbs software to develop the program that drives the CNC. The process may begin with customer-provided geometry in an IGES file, which Virtual Gibbs imports. In other cases, Boulard defines the part geometry based on drawings provided by the customer. Boulard typically produces a rendering of the geometry for customer approval.

He then programs the part by subdividing it into various geometric features and associating a cutting tool and machining parameters, such as cutting speed and feed rate, to produce a toolpath.

Typically, a piece of RenShape or medium-density fiberboard is mounted on the CNC's vacuum table, the program is called up, and then the router works on its own to produce the parts. Most parts take 1 to 5 hours. After parts are formed they are sanded and finished with paint. The resulting physical model provides the product-development team with a realistic view of the proposed design. These models can readily be evaluated (compared with renderings, which cannot as accurately represent how an object appears under certain lighting conditions).

Another CNC speed advantage comes when producing variations of models. Frequently, consumer products manufacturers produce several different design models for appearance and functionality comparison. Using power tools, it takes essentially the same amount of time to make each variant. The RG CNC unit, on the other hand, reduces much duplicative work. Boulard builds a CAD model of the first concept design, but then starts each additional design with a copy of the original design–modifying only what is required and saving considerable time.

























[above] GE indoor tankless water heater, designed by Norman Boulard, requires little space in the home.

"The RG machine has provided a major boost for my business by making it possible to produce a typical model in two days compared to two weeks in the past," Boulard said. "During most of that time I can be doing other work since the machine is operating by itself cutting out the pieces that I will later sand, paint, and assemble to make the finished model. The accuracy and level of detail of the parts produced by CNC is much higher than I could do by hand. CNC machining is clearly the wave of the future in the design and model-building business."

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