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Wood
and Wood Products Magazine
Feature Story September 2005 Gun Case Manufacturer Finds Increased Production with CNC Router: Champion Safe has boosted its daily production by 400 percent with the introduction of CNC equipment* When Champion Safe used power tools
to produce racks for its gun cases, each person could only produce
enough parts for 20 to 30 safes per day. To increase productivity, the
Provo, UT-based company invested in a CNC router that works unattended
to produce parts of any shape based on a computer program. Now a
single person can produce all the parts needed for 120 safes in one
day. This switch to automated routing increased Champion’s
productivity by 400 percent. Quality has been substantially improved because the CNC router does not make mistakes and cuts to an accuracy of 0.002 inch compared to typical 1⁄16 accuracy for manual cutting. "We have substantially reduced our manufacturing costs while increasing our quality," said Terry Zierenberg, director of engineering for Champion Safe. Previous Machining Methods The notched racks inside the safe that hold the guns are cut out of 3⁄4-inch particleboard. The geometry of the racks is complex because each rack typically holds 20 to 30 guns.
In the past, skilled woodworkers cut these racks using hand routers with bearing bits by following templates and with table saws. The accuracy of the racks depended on the accuracy of the templates, and making good templates required patience and a lot of experience. Frequently, templates were ruined and new ones had to be made before the job could continue. A skilled craftsman was needed to accurately follow the lines of the template. Even though the operator would follow the template carefully, he or she might bump corners or otherwise damage the template so that it got worn out and had to be replaced. This is why Champion was only able to produce enough components for about 20 to 30 gun safes per day. Five people would have been needed to handle today’s production volume. Zierenberg says he had long thought about purchasing a CNC router to perform this operation, but, when he originally checked, the cost put the machine out of reach. "When I worked for a competitive safe company, we bought a CNC router for $65,000," he says. "Prices have dropped since then but until a couple of years ago, the cheapest machine that I could find that would do this job cost about $45,000, which was more than we could justify." These were machines with servo motors and ball screws that provide high levels of accuracy and also with large tables that make it possible to produce big parts. "We didn’t want to spend that much because we only have one group of wood products so we can only use the machine in a few areas," Zierenberg adds. He says he saw a demonstration at a local dealer and "I decided that for that money it was worth the gamble." A Mix of Performance and Economy
Techno’s LC Series CNC router, which is the system Champion Safe finally decided to purchase, features ball screws on all three axes, offering smooth motion, a high level of accuracy and repeatability, and minimal maintenance. Champion chose the router because the ball screws do not have the play or the requirement for adjustments that racks do nor do they wear as easily as a rack. The company also notes that the closed-loop servo control system provides constant position feedback, higher power and smooth continuous motion that eliminate the possibility of losing position in the middle of a part. In addition, the servo motors are suitable for 3-D applications because they can change speed on the fly without losing power as steppers do .Zierenberg generated programs for the gun racks and a number other wood parts, such as center dividers, used in Champion’s different models of safes. He designed jigs that hold the particleboard blanks in place, into which an operator can a precut blank and then call up the appropriate program.
Zierenberg says this has freed up the operator to work on other projects while the router is at work, thus increasing productivity even more. It typically takes the router about one minute for each rack that is machined; some racks are more complex and take as long as four minutes. The increase in productivity that has been achieved with the new machine has significantly reduced Champion’s manufacturing costs, Zierenberg reports. "Clearly, the availability of high-quality, low-cost routers has the potential to dramatically improve the profitability of every manufacturer that uses wood in their product," he says. "Our savings extend through the assembly process as well because the more accurate parts that we produce with the new CNC router avoid the need for manual fitting. Having lower manufacturing costs than our competitors gives us the opportunity to offer greater value to customers and increases our sales volume. Higher productivity means that we are able to handle this volume without adding workers, which increases profit margins."
*This article has been reproduced for the Techno CNC Router Systems Website with permission from:
For more
information contact: Techno, Inc., 2101 Jericho Turnpike, New
Hyde Park, NY 11040. |