A shift in consumer demand and a quick response by a major appliance maker presented a series of challenges for prototyping firm.
When consumer tastes change, appliance manufacturers have to respond. That was the case when stainless steel refrigerators came into vogue. Aided by their frequent appearance on home decorating TV shows, appliances with stainless steel outer panels, particularly refrigerators with French doors, became the hottest item in home décor and manufacturers scrambled to get new models into stores. Among these was GE, one of the world's largest appliance makers. For help in getting new product to market fast they turned to 3-Dimensional Services Group of Rochester Hills, MI.
3-Dimensional Services is a firm that specializes in design, engineering and analysis, in-house tool construction, and complete build of first off prototype parts and low to medium volume production runs. Their use of advanced process methods, manufacturing technologies and staff talents mean prototype parts - not just models - are typically provided up to 70% faster than conventionally equipped prototype shops are able to offer. stainless steel outer doors to meet market demand," recalls Steve Kelly, senior sales engineer for 3-Dimensional. "GE had to move fast in order to get these new models into the stores by spring in order to take advantage of this major sales opportunity. Our part in the process had to be done fast and it had to be done right."
3-Dimensional's part was to create the outer door panels for five new models of stainless steel French door refrigerators (two French doors and a freezer door per model). Approximately 250 three-door sets were required for each of the five models. In addition to the stainless, these five new French door bottom-freezer armoire style models required that some doors be formed from smooth pre-painted cold rolled steel and others to be formed from textured pre-painted cold rolled steel. This meant that 3-Dimensional Services would be dealing with different material thicknesses, ranging from 0.024 in. to 0.032 in., depending on the material employed. To top it all off, the entire project had to be completed in eight weeks.
The first challenge was to create the tooling for the four hydraulic presses, ranging from 400 to 1600 ton that 3-Dimensional Services intended to use to make the new parts. The company was assured of having precisely the right presses for the job because its stamping area, with an array of presses from 20 to 7000 ton, surpasses the capabilities of many production shops, equipping them to handle everything from simple bends to complex tooling. The rapid creation of accurate tooling is, of course, a problem the company faces and solves on a regular basis. This project, however, had another dimension.
The challenge of staying number one
"These parts had to have a Class A finish, free of scratches or blemishes or any kind," says Mike Baranowski, Program Quality Assurance Manager. That's because GE wanted models available for consumer in-home testing, as well as in Home Depot as sales display models, even before full production began, in order to gain a step on the competition in this rapidly changing market.
"They wanted the highest quality prototype parts we could produce," continues Baranowski. Toward that end 3-Dimensional created tooling with steel inserts to ensure optimum part definition. This was no small order as multiple die sets for each of the five models were required. This was accomplished in approximately four weeks. The tooling was meticulously polished to help ensure a cosmetically superior finish, and the parts were protected with plastic sheeting during forming.
Subsequent to forming came trimming operations, first with trim dies and then with 3-Dimensional's 3- and 5-axis lasers. The capabilities of the company's numerous lasers coupled with years of in-house laser cutting expertise enable 3-Dimensional to achieve optimum tolerances on everything from thin sheet metal to thick armor plate. Its 3-axis laser cutting systems provide speed, accuracy and flexibility, while its 5-axis systems are ideal for cutting complex contours and shapes. In addition to laser trimming, careful handling of the parts as they were transferred between operations helped ensure that the excellent finishes were maintained.
Quality, of course, was a major focus of the entire project, but the formal stage of the quality function was a three-stage process. There was a visual inspection of all the parts. This was critical, as it was the same inspection that customers would perform in the stores. For dimensional accuracy coordinate measuring machine (CMM) inspection was employed with the CMMs taking data points every 100 mm.
Finally, there was fixture inspection. Like everything about this project, the check fixtures had to be created quickly and accurately, so 3-Dimensional Services used stereolithography (SLA) to create them, with the SLA's laser beam rapidly curing light sensitive polymers into the desired shapes. The check fixtures mirrored the plastic end caps that GE would fit to the tops of the doors. They had to fit precisely in order for the doors to open and close easily - a must for consumers.
But rapidly producing dimensionally accurate and cosmetically attractive parts was not the last challenge: 3-Dimensional had to ensure that the parts would arrive at GE in the same condition. Not convinced that conventional packaging would do the trick, 3-Dimensional created its own. Using a CNC heated wire machine, 20 lb. polystyrene foam end pieces were cut to the precise shapes the 3-Dimensional team determined would best protect the large thin door sets and their excellent finishes. The design was so successful that GE adopted it for their use once the parts were in production.
Responding to GE's stringent quality and time constraints, 3-Dimensional created 250 door sets for each of the five new GE models in a brief period of time, no mean feat. As Mike Baranowski observes, "The challenge didn't consist merely in making the doors, the challenge consisted in making the doors, the check fixtures, and designing and manufacturing the packaging, and doing it all in eight weeks in order to help GE re-energize its product line. That was the big story."
The 3-Dimensional Services Group, consisting of 3-Dimensional Services, Urgent Plastic Services, and Urgent Design & Manufacturing, provides rapid prototyping low-volume production that include laser processing, injection molding and casting, stamping, machining, robotic and manual welding, waterjet, hydroforming, tube bending, vibration welding, casting and pattern fabrication, RIM tooling, SLA and LOM rapid modeling, and assembly.
3-Dimensional Services, 2547 product Drive, Rochester Hills, Michigan 48309
Phone: 248-852-1333 Fax: 248-852-2110 Internet: www.3dimensional.com