Whether a company is large or small, nesting can provide greater production flexibility. Here are the primary considerations for deciding whether it is right for you.
Nesting refers to the process of efficiently manufacturing rectangular, shaped and non-symmetrical parts from flat raw material, including composite wood panels, large solid wood panels or plastic sheets. The components in a nested-based process are positioned in a pattern that will achieve the best possible material utilization.
This is nothing new. Most of us have experienced nested-based thinking in our daily lives. A prime example? When we bake Christmas cookies, we roll out the dough and press the cookie cutters in the best possible way to maximize the valuable material.
A new CNC machining center with the ability to apply labels on the router table before nesting has helped boost panel processing capability for Desco Professional Builders, Inc.
Nested-based machining typically involves placing a single sheet of material on a CNC router table. The router is programmed to process components based on the machine’s capabilities, in a single setup without any material handling required, other than loading and unloading. CNC-based nesting (cutting out components) processes with a router bit, eliminating the need to cut parts on a panel saw. The only limitations of executed operations are by the overall CNC nesting equipment configuration ‚ head and table. More advanced CNC routers can vertically size, rabbet, dado, groove, bore, shape, pocket and perform other operations required on each part in the nest.
The simplicity or complexity of the CNC nesting equipment will be determined by the company’s requirements and its capital equipment budget.
In today's competitive environment it is imperative to manage the two most significant line items on our financials efficiently: material and labor. These are the main reasons why you will find CNC nesting technology applied in large organizations, as well as in companies with only a few employees.
In typical nesting, a CNC router cuts out components with a router bit on a single sheet. (Photo: DeLeers Millwork)
Nested-based manufacturing also is applicable to a wide variety of wood products including: cabinets, fixtures, furniture, etc. The application of nested-based technology can vary based on a company's current or future demands.
The motivations for smaller or start”“up organizations to consider CNC nesting are the overall start-up or expansion capital investment and human capital requirements. Larger organizations are usually motivated based on volume and product portfolio, to consolidate entire component family processing into one machine and at the same time gain on human capital utilization by integrating other sequential process steps around the equipment using work cell concepts.
In any case, the common denominator for considering nesting is to reduce the overall labor portion for making components, increase material optimization and utilization, gain value-added facility space, improve component quality and enhance component flexibility. At the same time, nesting technology enhances the make-to-order environment which enables the companies to become more responsive to fluctuating business cycles, and it helps reduce inventory.
Consistent Accuracy, Part After Part
Because a CNC router has repeatable accuracy when performing multiple steps ‚ such as sizing, grooving, boring, shaping, etc. ”“ the nesting process is very predictable and leads to the manufacture of consistent parts with tight tolerances. This dramatically reduces the replacement or rework of components, and the nesting concept drives production to a lot size of one.
Today’s state-of-the-art technology provides high-feed speeds and faster tool RPMs, providing a better edge finish and less machine-related setup or downtimes compared to a point-to-point machine. In addition, flow-through vacuum hold-downs provide fast or zero setup for large parts (sheets) and secure work-holding for very small components.
Software is key to the overall success of nested-based manufacturing. Information integration can start from order entry of part design directly to the machine with the overall goal to eliminate manual manipulation and human interference. The more information that can be sent to the router, the more efficient the equipment will become, and return on investment will improve significantly.
There are primarily three levels of software nesting integration:
- Programs that contain nests generated by a CAD/CAM system;
- A CAD/CAM system that is enhanced with a parametric extension to design components and products; and
- A program that facilitates complete automation of nesting and machine code generation.
The company's size is not the most critical factor in determining the level of integration a company should strive for. The degree of customization is the bigger factor. The more make-to-order that is required, the more a level 3 is warranted.
As our various industry sectors evolve, nesting technology also will advance to meet those specific needs. Most importantly, if your organization is considering nesting, you need to do your homework. This includes defining your objectives, goals, benchmarks and expected results based on your product portfolio and your envisioned manufacturing model.
Michael Pfeifer is partner/senior project manager for M+M Wood Solutions of Markham, ON.
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