Century meets the challenge of the chair.
A tour of Century Furniture's Hickory, N.C., chair plant invariably begins at its celebrated machining center department. Who can resist an opportunity to watch six single-head, five-axis CNC routers strut their stuff? All Shodas, the "super six" are intrinsic to plant operation, said Wade Yount, plant manager.
The 240,000-square-foot Main Ave. plant is just a few miles from Century's main office and case goods plant. A total of 300 employees there produce from 1,500 to 1,600 units (including small lots of finished, purchased cases and occasional pieces) each week. At least 200 chair styles are in the Century line at any one time. It is difficult to imagine a successful operation this size without the support of its CNC equipment, which also includes a Tyler CNC bandsaw.
Century Furniture purchased a Shoda NC-1U router in 1988 because the company was looking for a way to make complicated parts with more consistency. Standard machining processes, which included bandsaw, sander, shaper, borer, buck shaper and spindle carver, led to built-in inconsistencies as parts moved from one machine to the next -- and caused headaches for the chair assembly department.
The benefits of CNC technology quickly became apparent: Less waste, even on large runs; less set-up time by eliminating older machines; less silvering; less sanding; and better joinery were factors that helped Century cut costs and improve quality.
Technology pays for itself
Because the first CNC router fulfilled Century's needs so successfully, a second one was ordered within a year. Not only was the plant able to machine its hardest parts via the CNC equipment, it was also able to reduce the percentage of components out sourced. Three more Shoda routers followed in rapid succession and the sixth was delivered in 1993.
Two of the routers have removable six-axis fixturing, allowing them to be used to turn posts as well as to perform five-axis functions. However, fancy front posts, such as a Chippendale cabriole leg with acanthus leaf knee and ball-and-claw foot, are still purchased, Yount said. The routers were not intended to replace carving machines, and they have plenty of work without adding that function.
A CNC pioneer
Century pioneered the use of five-axis machining in the furniture industry, according to Yount, but not without first clearing some formidable hurdles. A critical requirement was the capability to program parts offline, rather than having to teach the machine how to cut each part for 200 different chair styles.
Another hurdle was being able to fixture the part and perform all necessary machining at one time. The company wanted to do this with minimum set-up time and with maximum repeatability. Yount said that after a particular part is programmed, the computer-controlled machinery saves vast amounts of set-up time and provides greater than 99 percent accuracy and consistency, as well as unlimited repeatability. The CNC equipment also expands Century's capability of producing ever more difficult chairs.
The machinery really shines at machining tricky chair parts. Unlike cases that originate as basic boxes with 90-degree angles, chairs may have compound curves, like a concave back that curves from side to side, with another curve from top rail to bottom. Such three-dimensional shapes are made of parts that cannot be cut flat.
Although a curving chair suggests a welcoming, comfortable place to sit down, it poses its own set of problems for the manufacturer. It must sit well and have the right pitch to accommodate the user. Those are givens. But what about chairs with curved backs, or chairs whose curved parts join straight parts? These are not easy chairs.
Design by Faber, back panel by Shoda
The Villadomain chair, designed by William Faber and introduced in October 1992, has an intricately shaped and pierced back panel that is run on the CNC router. One of Century's most difficult chairs to manufacture, its back is one big circle with a continuous, dimensional bend.
Three separate pieces of solid maple are run through the moulder for shaping and curving, and edge-joined with tongue and groove construction. The resulting panel is then routed out on one of the CNC routers in a process that may have taken two weeks to program.
The Villadomain armchair with pierced back has a curving arm that becomes its front post. Other chairs in the line have cane backs with reeded front posts, or high, upholstered backs and twisted arms with interlaced tracery around the curved seat rail.
A 'Serious Constraint'
"We buy some dimension stock," Yount said. "The thickest lumber we buy is 8/4. If we need a 2 1/2-inch by 2 1/2-inch square workpieces, we may glue it up. But if it is for a front post, we prefer solid stock, so we will buy that from an outside source."
Panels no thicker than 2 inches are used to cut back posts. "We run those parts in our rough mill here," Yount said. "We've been looking at Stanley Furniture's 'Program of Serious Constraints' in which you try to discover what is hindering your flow through the plant. One of our constraints was at the cut-off saw. We couldn't seem to cut enough lumber, even though we have two cut-off saws," he said.
"We looked at that particular area, trying to find out how to relieve the constraint. Many times we were down and not cutting lumber because the cut-off saw operator was driving the forklift. We were actually short one person," Yount said.
After the constraint was identified, another man was hired as a driver and cross trained to operate the cutoff saw. He drives the fork lift, allowing the first operator to keep the saw running continuously. When extra large loads are run, the second driver/operator is available for the second saw.
Outstanding finishes are another part of the Century success story. Sixty or 70 different finishes are shown on the sample board. Wood finishes (up to No. 37 -- washed white) are done at the chair plant, where an 18th century mahogany finish has "most favored" status.
About 35 specialty finishers work out of plant nine, the old Habersham plant purchased by Century five years ago. They produce premium paint, lacquer and faux finishes. A couple of new finishes have moved to the top of the best-seller list there: No. 89 Old World, a distressed, crackled and worn finish, and Burnt Suede, a light tan, lightly pigmented paint that is slightly transparent, allowing the wood grain to show.
Because finishes are run in different plants, Yount said it was necessary to find ways to make end results more consistent. Matching dining room chairs to case goods is critical. At one time, each individual plant had a color panel to go by. "We thought each panel matched," Yount said. "For example, No. 342 Villadomain finish on chairs was expected to match the case goods finish. But we found that the panels varied somewhat."
Now a corporate committee determines which master colors Century's various plants will run. All sample panels are being redone. "We try to have solid and veneer parts represented, so we can match the color we are supposed to be going by," Yount added. The panels are finished at the same time, then distributed among the plants. A formula goes with each color, and the master panels are under lock and key.
Wood Products Division
In 1992, Century management created a Wood Products Division to include the chair and case goods plants, and the former Sutton Fine Furniture facility in East Bend, N.C., where Century's high-end reproductions are made.
Bob Bliss, former vice president of the chair division, became vice president of manufacturing for Wood Products. Yount came to the chair plant after 10 years at the case goods plant where he was finishing superintendent. Former chair plant manager Roger Jones now heads the case goods plant.
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|Title Annotation:||Design Lines; Century Furniture Co.|
|Publication:||Wood & Wood Products|
|Article Type:||Company Profile|
|Date:||Jul 1, 1994|
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