By Candace Sofianos King
As technology continues to reshape the woodworking sector, we investigate how computer numerical control (CNC) technology is changing timber for a more innovative, sustainable and efficient industry.
In the wood processing industry, computer-controlled automation is garnering greater attention and is swiftly becoming an important element of production technology within the timber sector. Computer numerical control (CNC) machining is a manufacturing process in which pre-programmed computer software dictates the movement of factory tools and machinery.
CNC machines employ the on-board computer to perform all control functions to execute the machining processes. They represent complex and integrated CNC machining centres, which execute the various machining steps on the workpiece secured into a workpiece clamp. Turning, sawing, milling, drilling, sanding or gluing is all performed on the wood using programmed tool motions.
With manual intervention and conventional control elements eliminated, control motions are instead performed with a computer keyboard or through the click of a mouse. The functions and operation are observed through a monitor, and the computer controls the machining centre with the data entered to execute all feed motions and clamping processes.
CNC machining centres are in use particularly when various wood species need to be machined, frequently also in combination with other materials. Solid wood or wood materials, such as plywood, particle board or medium-density fibreboard (MDF) panels, can be milled (CNC routers), sawed or sanded automatically and in series production. This allows CNC machines to produce construction elements (doors and windows), for solid wood processing (furniture and interior design) and for panel machining.
The tool changer in the machining unit allows CNC machines to execute a variety of processing sequences. The tool can be changed in the background while the processing sequence is completed, facilitating time savings. Since most processing steps remove material in the form of chips, these chips are permanently vacuumed from the CNC machining centre during the process.
Benefits and challenges
CNC technology has created and enabled new business opportunities, efficient products and safer environments. Coupled with this, it has produced products with longer lifespans and higher technical standards. Through CNC technology, the manufacturing operation can significantly achieve higher machining accuracies and speeds, thus reducing the frequency of defects and the risk of malfunctions.
Highly flexible, CNC machines use text or graphics-based reprogramming interfaces which can easily be modified to accommodate individual workshop needs and
applications. CNC technology boasts a close link to the use of computer-aided design (CAD) applications which are used to directly develop and implement unique programmes for the CNC machine at hand.
In an effort to meet market demand and cost pressures, wood processing operations are increasingly adopting CNC machinery. Venetta Dudley, owner of VVA CNC Machines, says CNC technology has tremendously reshaped the timber manufacturing sector.
“CNC boasts many benefits in the timber industry – it has improved timber manufacturing production times. It not only offers higher accuracy levels, but also results in less waste creation and allows for staff to be taught a new skillset. CNC is great for repeatability of large projects as it allows clients to be able to get the most out of their material,” notes Dudley.
When it comes to adopting CNC technologies, the commercialisation and investment in new technology factories can be challenging. In this case, Dudley says smaller businesses are faced with the greatest challenges.
“Firstly, the outlay on capital expenditure can be hefty in the beginning, however, if companies lay all the pros and cons down, analyse how the technology will change the way they run their production, and see the opportunity to grow within their industry, then the challenges become new goals instead. Welcoming the technology will also offer the possibility to enter new markets,” she highlights.
“There are new trends popping up everywhere you look – we have only skimmed the surface in South Africa.” – Venetta Dudley, VVA CNC Machines owner.
With technology constantly fleeting, new innovations are frequently coming into play. The latest technologies and innovations in this field include 3D simulations and printing, scanners, automated factories, distance controls, energy and raw material efficiency.
While not a new trend, nested-based manufacturing (NBM) is increasingly becoming important for production processes, notes Dudley. “Nesting helps to get the most out of your material – they allow for the advantages of accuracy, repeatability and efficient mechanical movement,” she adds.
Dudley notes the future of existing technology can be reshaped by numerous factors, including different concepts of design and manufacture, mass production, as well as the versatility of cutting by extending the axis on all machines – old or new.
“Future CNC trends include empowering machines to be guided by user-friendly applications that can be integrated into personal computers for the smaller business – making it more affordable. There are new trends popping up everywhere you look – we have only skimmed the surface in South Africa.”
CNC wood router benefits
- Speed and increase of production.
- Accuracy, less waste of materials.
- Learning new skills.
- Enhanced creativity.
CNC wood processing machine configuration
Machine frame: A basic unit of the machine that houses the control panels. The machine drive is generally also located here. The other traveling units are installed with the machine frame as the foundation.
Vacuum fixture with suction elements: Using the suction elements on the vacuum fixture, the workpieces are precisely located in accordance with the tool size. The vacuum fixture adjustment is controlled from the computer. This is accomplished in part with laser technology. The vacuum fixture and the suction elements can be controlled independently.
Machining bed: Workpieces are clamped on the processing or machining bed for subsequent machining. Some machines are equipped with multiple machining stations that can be operated independently from one another.
Machining unit: The CNC machine functions are centrally located in the machining unit. Various processing steps can be executed that depend on the installed tools.