Switching from manual machine tools to a CNC router helps a custom plastic fabricator produce a wide range of products on the average in one-fifth of the time required in the past. RBC Enterprises makes safety guards for machinery, control panels for electronic equipment, housings for medical laboratory equipment and a wide range of other products. In the past, when the company produced all of its products on manual machine tools or power tools, the company had to turn away many more complicated parts because it would have taken too long to make them.
Recently, the company switched to a CNC router that automatically machines the most complex parts to a high level of accuracy in much less time. The key difference is that RBC Enterprises owner Robert Couts now defines the geometry for the parts in computer aided design (CAD) software. Then the CNC machine automatically cuts out the parts based on the CAD geometry. “For example, it used to take 16 hours to manually produce 32 polycarbonate timing windows,” Couts said. “Now I can make those same parts in one and a half hours on the CNC router.”
Challenge of producing complex parts using manual methods
Couts has spent his entire life in the custom fabrication business and founded RBC Enterprises in 2002. When he first started the company, he built parts as he had been doing his entire life, manually cutting out the pieces on vertical milling machines, table saws, routers and similar tools. “Producing quality parts by hand is a time-consuming job that takes a considerable amount of experience,” Couts said.
“For example, the timing window consists of a 12 inch disk with a series of holes around the perimeter,” he continued. “Each hole has to be located very precisely in relation to the others. I used to lay the part out on with an indexing head on a milling machine. It took about 30 minutes to make each part. This was a very exacting task that required a considerable amount of skill. Even a very experienced person could easily make a mistake and spoil a part.”
Moving to CNC machining
Couts felt that CNC would solve these problems by ensuring consistent accuracy. He looked at CNC machining centers of a size that could handle the company’s largest parts. He discovered that the least expensive machines in this class cost in the neighborhood of $100,000, which was more than he could justify for this operation. These machines were generally very heavy machines with a cast iron base that were primarily designed for cutting metals. Couts looked around for a less expensive alternative and discovered the Techno LC CNC router. This router provides the accuracy, speed and ease of programming and operation he was looking for. The machine was designed specifically for the materials Couts works with such as polymers, wood and nonferrous metals. The machine costs less than $20,000 fully equipped with software.”
“I spoke to Tim O’Connor at Techno and he was very helpful,” Couts said. “He had logical answers to all of my questions so I made the decision to purchase the LC router. I have been very happy with that choice. The machine is easy to use and it has been quite reliable. Any time that I have had problems I have simply called Techno and received immediate answers. For example, once a servo motor went out. The Techno support representative helped me troubleshoot the problem. Then the sent a new motor by next day air. He also walked me through the installation and recalibration process so in only about 24 hours from my first call I was back in business.”
Need for accuracy and reliability
Techno's LC series CNC routing system provides a number of critical features that allow it to deliver accuracy and long-term reliability of a level that has previously only been available from machines at a much higher cost. The LC Series machine is constructed on a heavy steel base that includes a t-slot aluminum table surface, ballscrews on all threes axes, closed loop servo motor drives, and comes with Techno's Window's based G-code interface that is upgradeable free for the life of the machine. These premium drive components on the machine offer smooth play-free motion, a high level of accuracy and repeatability, and require minimal maintenance. The closed loop servo control system provides constant position feedback, higher power, and smooth continuous motion that eliminates the possibility of losing position in the middle of a part.
The machine is available in five sizes, with work envelopes of 30 by 24 inches, 48 by 48 inches, 48 by 96 inches, 59 by 120 inches, and 78 by 120 inches. Each of these models provides a repeatability of 0.001 inches, a resolution of 0.0002 inches and a maximum speed of 250 inches per minutes. A wide range of optional equipment is offered including a laser scanning module, CNC lathe attachment, Porter Cable router, vacuum blower, and fourth axis rotary table. The 4-foot by 8-foot model base starting price is $18,100.
Producing complex parts in less time
Couts now produces all of his more complicated products on the CNC router. He begins by laying out the geometry using the EnRoute 3 Professional computer aided design/computer aided manufacturing (CAD/CAM) software from Scanvec Amiable, Philadelphia, Pennsylvania. For example, it took Couts about 20 minutes to design the timing window. Then he generated the G-code needed to operate the machine and exported it to the machine controller. Now, whenever he needs to produce the part, Couts loads a 4 by 8 foot sheet of polycarbonate, selects the program and turns on the machine. Then he can attend to other business while the machine cuts out 32 parts in about 90 minutes. While the part is running, Couts typically programs the next job or prepares quotes for customers.
A cam is another example of a part that Couts previously produced manually and now makes on the router. He used to make the part from ¾ inch thick plastic sheets using a manual router. The part was difficult to make because it consists of a one-inch wide arc about three feet in length. The narrowness of the part meant that chatter was a frequent occurrence. The person making the part used their hands to steady the part but this was risky since their fingers were near the cutter. It used to take about two hours to manually route 10 parts but Couts can now produce 10 parts in 30 minutes on the CNC router. The CNC router provides major improvements in accuracy and surface finish. Couts can also provide the parts with less than half of the material required in the past since he can program the CNC router to nest the parts much more efficiently.
Couts said that RBC Enterprises now generates about half of its revenues with the Techno LC machine. “My sales have gone up because the CNC router makes it practical to produce parts that are much more complex than the parts that I was limited to in the past,” he said. “In particular, I have obtained many contracts in the military, medical and industrial machinery markets that I would have been unable to compete for in the past because the parts were so complex that I could not meet the required tolerances with manual machining or because it would take too long to make them by hand. If someone took my CNC router away from me I would have to consider closing my business.”
For more information on the CNC Machine described in this article, contact Techno Inc., 2101 Jericho Turnpike, New Hyde Park, NY 11040. Phone: 1.800.819.3366 or 1.516.328.3970, Fax: 1.516.358.2576, E-mail: firstname.lastname@example.org, Web site: http://www.technocnc.com
For more information about RBC Enterprises, Inc., contact Rob Couts, Ph: 443-524-2487, e-mail: email@example.com, Web site: http://www.rbcenterprise.com. RBC Enterprises is located at 6801 Eastern Ave., Baltimore, MD 21224.