Charlie Van Dusartz had a custom three-phase converter built to ensure his CNC machine had the clean power supply it needed.
CNC automation has increasingly become a routine part of the most successful cabinet and furniture operations. But most companies still have lots to learn to get the most out of CNC machining. Here are some lessons from successful CNC operations.
1. Clean power is important
When Joni and Charlie Van Dusartz automated their cabinet shop in Hammond, Wis., the first challenge they faced was how to power the machine. The Van Dusartz’s shop is a single-phase shop with a number of three phase converters for the machines that need it. Their Biesse Rover CNC router needed smooth, uninterrupted three-phase power to run, so the two decided the time was right to have three-phase power run into the shop. They balked, however, when they heard about the $30,000-per-mile charge to run three-phase power to their shop, which was two and a half miles from the power supply.
In the end, a power expert from Schneider Electric Motors, Menominee, Wis., custom built a three-phase converter for them, which contains a filter to provide a steady power band.
Lesson: Check power requirements before new installations.
2. Not just cabinets
When Classic Woodcraft Inc. in Chatsworth, Calif., adopted CNC manufacturing, owners Jim Clark and Kevin Ontiveros found there were more benefits besides increased production capacity for cabinets.
They had been doing designing in Cabinet Vision and became attracted to the CNC possibilities of Thermwood’s routers and nested based manufacturing. “It just seemed to make more sense,” says Ontiveros, referring to the material handling advantages of the system. Since nested based manufacturing uses a CNC router to cut and machine all cabinet parts from sheets, there’s no handling of parts between a saw and joinery-related equipment.
Most of their work is residential kitchens, but Classic also does cabinetry and built-ins for whole houses, as well as some commercial work. “If somebody wants one shelf, I’ll do one shelf,” says Clark. The CNC has also opened up opportunities in more unusual projects such as display fixtures and lamp bases.
Lesson: One-off projects can be profitable and diversify your business.
3. V-grooving creates new product
Decorative Concepts of Boise, Idaho was born out of a desire to diversify and the purchase of a Northwood CNC router that was meant for another business. Owners of Decorative Concepts, Dale Wilson and Brett Hatfield purchased the router to cut cabinet parts for their cabinet shop, Western Idaho Cabinets, but they eventually set up the machine in a separate shop and diversified into a whole new product line: mantels and fireplace surrounds.
Besides product diversity, the CNC router opened the door to more innovation. For example, in the forms that make up the sides of the mantels, a small change in the way the pieces were cut on the router made it possible to have a perfect mitered corner with no hassle. When making the groove for the mitered corner the router is set up to stop just short of cutting through the material. Instead of two pieces that have to be lined up and joined together, the remaining material is thin enough to just fold over. With glue and a couple or rubber bands to act as temporary clamps a perfect mitered edge results, quickly and easily.
This innovation made possible one of the most popular product lines developed by Decorative Concepts -- the homeowner kit. The kit consists of the surround in three sections, the two sides, the mantel and fairly simple installation instructions. The builders’ kit, on the other hand, is in more pieces, although it is less expensive, and is meant for an individual more familiar with construction, such as a handyman or carpenter. It requires more assembling and will take slightly longer to install.
Lesson: CNC precision changes joinery options.
4. Manual and CNC processes can work together
Many cabinet shops treat automation as a one-way trip from which there is no turning back, but for some CNC shops the solution is a successful marriage of automated and conventional processes.
Mark Shelley, owner of Wooden It Be Nice, South Yarmouth, Mass., has integrated computers in the front office and a CNC point-to-point machining center in the shop with a host of conventional sawing and boring equipment. The result is less down time, and faster production as automated and conventional equipment are used constantly in a leap-frog fashion to get jobs down in the most efficient manner available.
For Shelley efficient production means no waiting for a machine. Typically, while Shelley is running parts on the Busellato Jet 4000 CNC point-to-point machining center, someone else is machining other parts elsewhere in the shop, including even doing operations that could be done on the CNC machine. For example, he might be drilling holes in cabinet panels with a Blum boring machine. Why use a conventional manual borer, when you’ve got a CNC machine?
Here’s an example. If the parts required only three holes, it’s fast, simple work for the Blum machine, and there’s no wait for the CNC to be free. The big machine can be used for more complex chores.
Similarly, the shop also has a Busellato horizontal boring machine in regular use. The CNC is capable of doing horizontal boring, but Shelley says it is faster, and less complicated to simply use an offline borer. Again, it’s likely that the boring machine will be in use simultaneously while the CNC machine is handling other parts.
Lesson: Don’t abandon manual processes if they can coordinate with the CNC.
5. Making offloading easier
Having a CNC router has not only increased efficiency but made some curved work more practical and profitable, such as these lamp bases.
Hall’s Edge in Stamford, Conn., uses its CNC router to cut cabinet and furniture parts for other shops. Owner David Hall, as a one-man operation, wanted a more efficient way to offload nested parts. He built a plywood rolling cart that slides up to the Thermwood router’s work table to help unload parts. He uses two identically calibrated spoilboards. When one sheet is machined, he simply pulls the parts and spoilboard off onto his cart in one piece. Then he slides the spare spoilboard onto the router, adds a new sheet of material, and the machine can keep on working while he sorts and process the parts from the previous sheet. And, of course, he built the cart from parts machined on the CNC router.
Lesson: Use the CNC router to make shop jigs and fixtures for more efficiency.
6. Safer panel processing
David Wilhoyte operates a California Closets franchise in Reno, Nev. Like many shops, he got into CNC manufacturing for increased efficiency, but he discovered other advantages, such as an improvement in safety.
Machine operators are less likely to come in direct contact with cutting tools. But CNC also typically means processing more heavy panel products, which means more heavy lifting. To make that both safer and more efficient, Wilhoyte added a Schmalz vacuum lift.
“Now one operator can lift the 80- to 90-pound panels with the vacuum lift,” he says. “Before, it took two guys to hoist the sheets.”
Lesson: Consider automating material handling as well as machining.
7. Don’t watch
Steve Ferguson of JDG Inc. in Eugene, Ore., jokes that he didn’t immediately reap the full efficiency benefits of his Techno CNC router when he first got it because he and the other guys in the shop spent too much time admiring it. “It was supposed to be a time-saving device, but for the first two months there wasn’t any time savings because everybody just watched it,” he says.
Lesson: Trust your machine and get on with other work.
8. Nested base production flow with sweeper and vacuum lift
When Desco Professional Builders Inc., a general contractor in Ellington, Conn., brought cabinet production in house, they were after maximum efficiency. That goal eventually led to fully automating the cabinet shop.
Robert Anderson, president, says, “Our retail customers require quick turnaround and short lead times. Our first cabinet shop was three guys with table saws and a 35-year-old edgebander. Today, we couldn’t compete without automating.”
Art Foote, who is in charge of the in-house manufacturing operation, says the company chose Delmac Machinery Group as their primary automation vendor because they offered a versatile system to fit the needs of custom work. That system includes a Busellato Jet 400 RT CNC router and an Omal HBD boring and doweling machine. Another important investment, Foote says, was the Schmalz vacuum lift that allows one man to easily process heavy panels. A Holz-Her Sprint 1310 edgebander rounds out the production. Microvellum software drives the front end of the process with shop foreman and engineer Shane Bruscoe at the controls.
One way they make the operation even more efficient is by optimizing it for single operator use. That means employing the vacuum lift for loading and a sweep program for offloading. When done with machining a sheet, the sweep function slides the entire sheet of nested parts to an offload table. There the operator can safely label, unload, and sort parts while the machine continues to machine the next sheet.
Lesson: Optimize CNC production for safe single-operator use.
9. Teaching the next generation of CNC users
Mahoning County Career and Technical Center, Canfield, Ohio, has integrated CNC training into the school’s regular carpentry and cabinetmaking curriculum.
John Panella, who teaches this program, set up the CNC section of the course as an option that not all students participate in, partly because it demands relatively high computer skills combined with reading comprehension. “We teach the students to program the machine using a software package that is popular among cabinet shops,” he said. “The most difficult task is defining the geometry of the part.” It is necessary to think through every detail of the part in order to fully understand its geometry. Then the students can use the software to construct the geometry on the computer, first in the form of lines, then surfaces, and finally as 3D volumes.”
For example, Panella often gives his students the assignment of producing a 12 inch deep, 8 foot high cabinet starting with 60 inch wide and 108 inch long melamine panel. Students learn how to create a program and download it to the machine, clamp the board to the machine table, hit the start button, and cut out their first cabinet.
Later in the course, the students get the opportunity to program more complicated high-end designs such curved cabinets. “The cabinetmaking professional is in the midst of a revolution because there is no limit to the designs that you can produce with a CNC machine,” Panella says. “It’s amazing what our graduates can do after they have had a year or two of on-the-job experience.”
Lesson: Encourage young people to learn CNC skills.