W&WP May 2004


Nesting Takes Off

Developments in software and CNC machining centers lead more woodworkers to implement nested-based manufacturing in their shops.

By Scott Bury


Nested-based manufacturing on CNC machining centers is catching on in the furniture and cabinet manufacturing sectors, in large part because of more user-friendly software.

Sales of CNC (computer numerically controlled) routing machines for nesting parts are increasing, particularly to smaller and medium-size companies, according to representatives of CNC router companies interviewed by Wood & Wood Products.

"We're selling three times as many nested-based applications as point-to-point machines," says Michael Cassel, CNC product manager at Holz-Her U.S. "Nested-based manufacturing is the most active part of the CNC market right now. The difference is the software."

"Sales of CNC routers are approaching half of our total sales," says Bill Blackmon of Delmac Machinery Group, which sells the Busellato JET line. "When you consider that we only introduced our first nested-based manufacturing system five years ago, that's amazing growth."

"(Nested-based manufacturing) has become an extremely important and large part of our North American machines," says Craig Sexton of Biesse America. He says Biesse now offers nine different models of CNC routers designed with nested-based manufacturing in mind, with table sizes ranging from 4 feet by 10 feet up to 5 feet by 21 feet.

"Nested-based manufacturing is not new, but now it's hot," agrees Greg Hammersley, Weeke product manager at Stiles Machinery. He says that nested-based manufacturing is a huge and growing sector of the wood manufacturing market, and it's driving sales of CNC systems. "The key is the software, which is much easier to use now."

"Nesting saves material and money," says Ken Susnjara, CEO of Thermwood Corp., noting that it streamlines production, optimizes yields and saves on labor.

What Is Nesting?

Nested-based manufacturing simply means cutting out all parts for a piece of furniture from a single sheet (or in some cases stack) of plywood, particleboard, sheet metal, plastic, fiberglass, etc. on a CNC router or machining center at one time. For wood product manufacturers, it means forgoing the need to size parts on a panel saw for further processing.

For some applications it is more efficient than using a panel saw to cut individual pieces - if it's done right. Maximum yield and efficiency requires a cutting design that places different pieces as close together as possible, often "nesting" curved or cut-out pieces together.

It takes a lot of experience to figure out the optimal way to arrange parts on a single sheet in order to get the highest yield and the lowest waste in a nesting operation. An experienced operator armed with efficient nesting software can make all the difference, according to Michael Kowalczyk, general manager of Display I.D.E.A.S, a manufacturer of point-of-purchase displays and other products, based in Houston, TX.

"On one job that uses 35 sheets of material, you can spend a whole day working on the nest design and still not be as efficient as a computer."

Kowalcyzk notes, however, that software programs designed to nest patterns to derive the greatest yield from a sheet of particleboard or plywood often require some "tweaking" to fully meet the individual user's needs. Still, he says it's essential for manufacturers to find ways to save on materials and labor to become more cost competitive. "Try telling your customers that they'll have to pay for all of the waste that will result from not nesting parts and getting high yield," Kowalczyk says.

Software Makes the Difference

In the past couple of years, nesting software has become cheaper and much easier to use. At one time, such programs were very expensive - up to $20,000 or more - and required high-end computers to work. Nesting programs are now available that can be run on office-standard personal computers with the Windows operating system, and cost less than $5,000. This has made nested-based manufacturing with a CNC router a viable option for a much broader range of manufacturers for several reasons: The software is now affordable for more businesses, and it runs on computers that all businesses have and know how to use already.

"The new software is much more user-friendly than it used to be," Cassel says.

"The latest version of Rolling Nest is very productive," Kowalczyk adds. He was a "beta tester" for the product and worked with Thermwood on the order of operations on the latest version so that the CNC router makes only one pass along the material to cut the nesting pattern, rather than traveling back and forth repeatedly. This advance boosts productivity even further.

Besides software, other advances make nested-based manufacturing with a CNC router or machining center easier and more productive. For example, the new Weeke BHC 350 NB Optimat, supplied in the United States by Stiles Machinery, features operator set-up assistance and LED guides to show the operator exactly where to line up material on the bed.

Quick-change positions on vacuum modules, which hold sheets to the machine bed, are also found on the Routech R500 CNC routing systems from SCM Group USA. The new Routech models also feature prismatic guides to ensure smooth movement and easier alignment.

Several equipment manufacturers are also adding operator set-up assistance, quick-change chucks and other innovations that make the CNC machines easier and more productive to use. Together, these innovations are making CNC routing a solution for more and more types of products and users.

Is Nesting for You?

Nested-based manufacturing can be a one-stop solution, but it is not necessarily the right solution for every wood product manufacturer.

"Nested-based manufacturing makes sense if you're using the right construction methods," says Susnjara. For knock-down assembly using dado construction, or mortise-and-tenon, CNC routing can be the right solution. However, a manufacturer using dowels, European-style panel-saw construction or anything that requires edge drilling, a point-to-point system is recommended, he says.

"Nested-based manufacturing using a CNC machine is a one-step solution for many manufacturers of kitchens, cabinets and furniture," Hammersley says. "You don't have to have a saw and a drill and a router, so you save capital costs, money and floor space."

Sexton describes the typical user of nested-based manufacturing as companies with up to 19 employees, machining more than 15 sheets per day, with limited floor space to produce residential and commercial cabinets, store fixtures, furniture, displays or any other product made from flat panel components. But NBM is not right for anyone "producing components at a volume that would consistently require a book height on a beam saw to be two or more sheets."

"It's not always the right solution for low-volume plants," Hammersley adds. "Each case has to be evaluated on its own merits."

"Nested manufacturing with a CNC router is suited to sheet goods materials with no side drilling or horizontal operations - where everything is vertically oriented," Kowalczyk says. However, he feels that a company can be productive combining CNC machining of nested products with a point-to-point system or a panel saw, by starting a new job on the CNC machine, while performing edge-drilling or other operations on another machine at the same time. "It depends on your volume and the number of parts in each piece that you're building," he says.

Also, consider your own production needs. A CNC machine has a top speed, and if your output requires production of more sheets per day than a CNC can produce, even with the most efficient set-up processes imaginable, then you should be looking at other automation solutions.

Nesting Will Grow

Suppliers say several factors will contribute to the growth in nested-based manufacturing over the next few years. They include:

* It can be a highly productive system for dado or mortise-and-tenon construction.

* Manufacturers are bringing out a wider range of new CNC machines every year, with an increasing number of applications, including different bed sizes and productivity options.

* Nesting software is getting easier to use - and sometimes is bundled free in the cost of a CNC router or machining center.

But of course, all that is dependent on the overall economy. Right now, interest rates are low and the housing market is strong - both for new home construction and home renovation. All that is driving a lot of kitchen and bathroom cabinet business.

A burgeoning market and advancing technology have added up to a lot more business before, and now it's happening to nested-based wood manufacturing.


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