Hickory Business Furniture is known as a producer of high-end contract and office seating. The company recently expanded its casegoods offerings with a line of desks, credenzas, conference tables, and occasional tables at last year’s NeoCon. When the decision was made to expand production of casegoods at its Hickory, NC, plant, the idea was to combine state-of-the-art technology into a flexible manufacturing system.

“Our idea was to be able to build one-of-a-kind pieces without seriously affecting the cost of the product,” explains Dick Little, vice president of manufacturing. “We wanted to do a custom product at about the same price as a standard product.”

In addition to flexibility, HBF wanted quality. “We wanted to be machining parts at a level where we could eliminate as much hand sanding as possible,” says Little.

Little knew he was asking for a lot. “We knew we would have to look at a total system — from software through the tooling on the machine,” he says. HBF had John Summey from North Carolina State evaluate the entire process with the goal of producing a flexible, high-end manufacturing environment.

“In this industry there are so many designers that want to modify what’s in a catalog, but they don’t want to pay twice the price,” says Little. “Our idea was to build a manufacturing system that reflects the way business is being done in the marketplace.”

The first thing Little thought they needed wasn’t software or hardware, but a person. “We wanted to bring in an engineering head from a company that specialized in the contract casegoods business because we didn’t want to totally reinvent the wheel. That’s when we brought in Tom Deady.

Deady, whose title is director, desk product planning, was given the task of pulling the software, machinery, and manpower together to make the project work.

The goal was to build high-end traditional casegoods using modern methods. As a result, HBF is using a combination of 32 mm box construction with hand-fitted details added.

“What we’re trying to do is use the quality details people expect where they see them,” says Deady. “We have people hand fitting components and hand mitering the bases and tops. But in between is a box built with dowel construction.

“We’re going through a complete transformation from build-from-scratch manufacturing,” says Deady. HBF still builds every piece to order, but every piece is first designed in the engineering department and then seamlessly transferred to production and directly to the machining center itself.

In HBF’s system, the customer can order a product — desk, credenza, return, bridge, table, or whatever — from the standard catalog and modify the dimensions. Say the customer wants a 64-inch long desk and credenza with a 44-inch bridge on the right side between the two. In the engineering department IMOS-CAD is used to develop the drawing for that desk from a library of parts. The operator can pull up the standard 60-inch top, stretch it by inches, and then modify the pedestals to match.

The finished piece is then output as a file which is pulled into ABC-CAM, a second program from Virtual Systems that translates the AutoCAD-based drawings to G-code that is read by IMAWOP, which is the windows-based program that operates the machining center. That may sound simple, but anyone who has worked with this level of technology knows it isn’t easy to set up.

“We had to put all the parameters and rules into IMOS and ABC-CAM to make it work, so you are working with all the same terms and tools,” says Deady. “It takes some time to set up, but once you do, it’s very slick.”

The result is that a special order can be received and processed through engineering in a matter of hours.

HBF’s casegoods manufacturing is a mixture of high-tech and craftmanship. Panels are purchased as laid-up veneer on particleboard and MDF cores from Sieling & Jones, United Plywood, and the Lane Co. HBF is a division of Lane, so it relies on its sister division’s expertise in panel processing

“For the standard casegoods panels that come from Lane, we select the veneers through McNeil Veneers,” says Deady. “Lane creates the cores, laminates the veneer to the core, takes them through their fill and sand process, and sends them back to us.”

Veneered panels are sent back to HBF in about 35 sizes. The IMOS program generates a bill of materials and panels are pulled from inventory. Parts that have to be cut go to a Homag Espana panel saw. Others go directly to the IMA BIMA machining center. A small Brandt edgebander is used to apply veneer and solid wood edges on case parts. A Comil case clamp is used for assembly of boxes.

Tops are cut to size and a solid cherry edge applied. In the case of the Courant desk and credenza tops, the edge is 2 inches by 1-3/4-inches. The corners are hand mitered and fitted. Then the top is taken to the IMA BIMA Quadroflex C-120 machining center where the edge detail is machined.

The BIMA machining center was on the show floor at IWF 96, and was purchased by HBF in the summer of ’97. It has a 12-position tool magazine and is equipped with a 7.5 kw router head as well as aggregates for horizontal boring, flush milling, and sawing. It has the capability to apply edgebanding to curved or straight parts.

“We are able to process quite a few parts on this machine,” says Deady.

Machining these large, complex edges was the biggest test for the machine. With custom tooling supplied by DeHart Tooling, the machine makes multiple passes to cut both male and female profiles. A desk or credenza top can have male edges on four sides, a return will have male edges on three sides and a female edge on the fourth. As a result, the finished return top will mate perfectly with the desktop.

“We make all our tops the same,” says Deady. “Our return tops cope on one end, bridge tops cope on both ends. Because of that we had to have insert tooling. The male and female profiles have to match up every time and after sharpening.”

Deady presented that problem to DeHart Tooling and the insert tools were developed. Because so much material is removed, shaping each edge requires six passes. Five passes are made with a rough cutter, and one with the finish cutter. The automatic tool changer allows the machine to change between the rough and finish cutter in the middle of the cycle. On return and bridge tops, it also changes between the male and female cutters during the cycle.

The finish quality of the pieces is where HBF wanted it. “From a quality standpoint this is giving us as good or a better cut than we asked for. There is very little sanding of these profiles down the line,” says Deady. “We’re saving money, saving work stations, and saving people.”

The machine was purchased to produce casegood parts. Deady says the cost justification called for it doing casegood parts two-thirds of the time and parts for occasional tables the rest of the time.

“Occasional tables are a good example of where we would have created a jig and shaped everything around it,” says Deady. Now they set the top on the vacuum pods, align it with a laser light, and machine the edges. “We just ran 25 bow-front table tops in four hours. That would have taken us two days to do in the past.”

The machine is also used to produce parts for the chair plant next door during down time. Deady used a front seat rail as an example. “We can put this on the machine, saw it to length, shape it, create a groove, and horizontal drill these holes. Then we have a finished part. Instructions for machining that part used to take up a page on a route sheet.”

In addition, simple plywood frame parts that would normally be cut on a band saw are machined on the BIMA during down time. “We use the plywood parts as filler. If we have an hour to spare, we throw on a spoil board and run parts for an hour.”

As new products are developed, Deady says the engineering department is now involved making sure the parts are CNC friendly to machine. If a part is changed from horizontal to vertical boring, for example, it speeds throughput.

“We’re trying to do this better than everyone else,” says Deady. “To do that you have to know what the cutting edge technology is, and partner with the right people.”

Tooling to tackle the job

One of the challenges faced by HBF was producing complex, large edge details from solid wood on its casegoods. The company could have used the traditional method of attaching mouldings to tops, but it’s impossible to guarantee a perfect fit and consistency using that method. In addition, some designs called for male and female profiles to mate between desktops and returns or bridges. That would have been nearly impossible using traditional manufacturing methods.

HBF’s solution was to attach a 2-inch by 1-3/4-inch cherry edge to a top and then machine both the male and female on the IMA BIMA machining center.

“We went to DeHart Tooling in February and showed them we wanted to create this fairly substantial edge detail with male and female parts,” says Tom Deady, director of desk product planning. “We gave them our parameters and told them the quality levels we wanted. Anthony DeHart said, ‘If that’s all you need, we don’t have a problem.’”

Insert tooling was also a requirement because of the male-female matching parts. “The parts have to match up every time after sharpening,” says Deady. “We’ve had very good quality as far as parts lining up.”

The resulting cutters are big — roughly 150 mm in diameter. “We have 10 of these cutters at a couple thousand dollars each, so we’ve invested heavily in tooling,” says Deady. “The idea is to spend the money here to control the shapes, the detail, and the quality of cut. That saves us a tremendous amount of money downstream in reduced sanding and fitting.”

There was some question whether tooling could be developed that would fit within the machine’s constraints on tool diameter and weight.

DeHart explains how DeHart Tooling achieved a solution. “We had to build tools in multiple-piece configuration. Basically it’s a set of stacked tools bolted together on an arbor.” The tool body is heat-treated alloy steel. The arbor is a 1-inch diameter shank chucked in a HSK collet. Balancing the tools was also a trick. “Each component had to be balanced, then the entire assembly mounted on the shaft and balanced as a unit,” says DeHart.

Due to the short development time available, the solution had to be achieved using off-the-shelf carbide inserts. “We had to use various manufacturers’ available sizes of blanks to produce this tooling,” says DeHart. “It made design more difficult, but in the end it’s better for the end user because they aren’t using custom inserts.”

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