CNC Wood Machining - Nesting
Among the more important and flexible manufacturing technologies for furniture manufacturers is panel based nesting, in which groups of parts are nested together for the most efficient use of material and production time from a single panel. CMS played a central role in the emergence of nesting technology in the early 1990's. But as with all technologies, the needs of the market continue to require an expansion of methodology and supporting capabilities.
- Nesting technology
CMS' continuing development of nesting technologies has been driven by its customer's needs which focus on nesting as a core company capability allowing for constant design innovation as well as a customer oriented approach for "just-in-time" and "made-to-order" strategies. CMS' expanded methodology in this area includes: flow through systems, random panel sizes, colors, thicknesses, labeling, surface floating and referencing of critical dimensions, broken tool detection and replacement within the cycle, increased high speed processing feeds, improved yields and reduction of loss due to tool diameter and outside edges, data tracking/collection and more.
AVANT flow through vacuum belt
Just one of CMS' many solutions for nested based panel production, CMS' AVANT is specifically designed for nested based panel production and features AVANT's moving gantry, fixed table system. AVANT's small compact foot print is perfect for inline and flow through production. AVANT controls all the aspects of nested based production starting with its innovative approach to panel holding, in which the panel is laid directly on a special belt specifically modified by CMS for vacuum holding of flat panels. The belt is enhanced with venturi openings to deepen the vacuum by which the panel is held, which, when exposed during the routing cycle as the cutting tool passes, are expected to lodge particles of a larger size to block their opening, further enhancing the depth of vacuum. The particles are removed from the venturi by a brushing/cleaning action at the end of the machine while the belt passes by it during the unloading phase while moving the panel and the cut parts forward and out of the machining area.
Machining of the parts is accomplished in a normal routing fashion, but the cutting tool is limited in its passage beneath the panel to protect the belt from damage, passing only several thousandths of an inch below the panel surface, which is ensured by AVANT's pre-machining probing cycle and automatic adjustment of the tool length in relation to the vacuum belt.
In addition AVANT also provides perfect alignment of the panel's end and side prior to the cycle beginning to make sure the panel is perfectly set for work to begin. AVANT also incorporates a range of basic vacuum zone sizes so as to provide the "best" match to a panel size and not waste vacuum.
Add to that the fact that AVANT is provided with all of CMS' basic technologies for machining and working units - Revolvers, ATC units, 5-axis working heads, multiple groups - and AVANT is up to any production requirement.
AVANT with automatic infeed and unloading area
This AVANT with flow through vacuum belt is also equipped with a special infeed zone and unloading area. In this setting AVANT is in a cell and may select sheets from multiple stacks, working with various thicknesses, dimensions, or colors, and automatic removal of the dunnage sheet when the stack is finished. The stacks can be prepared ahead of time with sheets of various thickness and color and the list of information about the stack can be retrieved by a barcode that is read on the stack prior to the cycle beginning.
AVANT also is equipped with a barcode labeling capability prior to a sheet entering the machining area, so as to maximize production time, in which a label is placed in various areas of the sheet and will be used to identify and track each part after it has been cut from the sheet.
AVANT's cutting capabilities are outstanding, permitting feed rates of up to 40 meters per minute with a 3/8" diameter cutting tool for panels up to 1" thick and 18 meters per minute with 5/8" diameter cutting tools on panels up to 1 5/8" thick, meaning AVANT can produce just-in-time for a multitude of sizes, thicknesses, and colors for even the most demanding flat panel production, such as office furniture.
KARAT - TX3 - waste board
CMS' Karat class CNC machining center is also used for nested based panel production. In this photo Karat is shown in a large double table version using a resurfaceable waste board for nested based production. Sheets to be worked are available from the infeed stack with another stack in waiting. When the stack is empty the dunnage sheet is removed to the nearby dunnage storage area. Sheets are moved to either table by the overhead vacuum infeed device. After the cycle the parts are picked by a "high density" vacuum cup unloading device and any scrap pieces or dust is removed from the table by a special cycle, which can automatically feed parts into a production line. Karat's double table version makes it possible for nonstop production to take place, highly efficient and productive.
Nested patterns, labeling and marking
CMS provides several approaches for part labeling; and nesting can be done in a standard or "true shape" manner.
Part labeling has become an important capability in many production settings so that parts can be tracked and later identified for incorporation into the correct final product. In this picture is shown one of CMS' part labeling systems. Labeling can occur prior to the infeed of the machining center, separately, and without loss of production time, or within the production cycle. Label printing can take place as the labeler is moved from one part label location to another, with the average time to print and apply a label being 3 seconds. In addition, and shown in the upper right corner, CMS also provides laser marking technology, in which the required information can be "burned" onto the part, as in this case, in the edge of an MDF door frame, which will later be concealed and not noticeable.
Nesting methodologies can also be exploited based on standard dense nesting, "3rd phase", cut patterns, saving significant amounts of material or even "true shape" nesting allowing for the best nesting of irregularly shaped parts for optimum material savings.
Nesting - added capabilities: roller hold-down, floating
CMS also provides enhanced technological capabilities for nested based production. In this photo, to the left, is shown CMS' roller hold-down system, with which it's possible to stack several sheets and machine them at the same time, significantly increasing through-put and even more importantly providing a capability which can be incorporated into CMS' flow through AVANT CNC machining centers resulting in the most efficient and controlled production possible.
In addition there are situations, see the photo to the right, in which it's necessary to have a perfect relationship of cutting tool profile to the surface of a sheet and since the cutting information is referenced from the bottom of the sheet, and not the top, and sheet thickness is not always precisely the same, profiled tool paths that need to accurately and aesthetically meet the material surface, such as in MDF cabinet door production, can benefit from CMS' unique floating head capabilities, which make it possible to have the tool always perfectly meet the surface, even when the material thickness isn't the same, by "floating" the tool on the panel surface.
Loading/Unloading: some options
Shown in this picture is one of CMS' loading options for an AVANT nested based cutting system. The infeed system can work from several stacks of material, and in conjunction with a labeling system, avoiding any loss of production time, since it's done while the machining work is taking place on another panel. The system incorporates automatic data retrieval by reading a barcode label on the top of the stack prior to work beginning, which provides information for both labeling and machining requirements.
In the picture, to the right, is shown CMS' "total surface vacuum compression" unloading device, which removes the entire nested sheet, including parts and scrap for further later separation and distribution work, freeing up the machining center to work at maximum uninterrupted speed.
Nested based technology has found a perfect manufacturing application for office furniture manufacturer Groupe Lacasse—one of CMSNA's office furniture customers—providing components parts for items such as:
- systems furniture
- lateral filing and storage units
- educational furniture
as can be seen in some of the following photos.
Casegoods: system furniture
Casegoods: system furniture
Casegoods: system furniture
Casegoods: system furniture
Wood Nesting: Case History and Technology Overview
A short case study of Groupe Lacasse and their integration of CMS' nested based panel technology into their system including a look at their extensive line of elegant and contemporary high end office furniture. This is followed by an overview of CMS' extensive range of CNC machining center nested based panel production solutions, either inline or stand-alone, with CMS' exclusive vacuum belt or waste board, manual or automatically loaded or unloaded methodologies, roller hold-down systems, floating heads, saw blades, labeling, laser marking, high speed routing and much more.
MDF kitchen cabinet doors
An AVANT flow through belt CNC machining center is shown producing MDF kitchen cabinet doors. The process for machining square corner doors is highlighted as well as the use of floating tools to ensure that the profiles remain constant with respect to the surface. The special dust collection hood is a highly efficient CMS solution and is shown extended and then retracted so that the machining work can be seen. Finally the special CMS "total surface vacuum compression" unloading device is shown removing the entire sheet when the machining work is finished.
Nesting Sector and Groupe Lacasse Case Study
(click folder on the left to download)