Computer numerical controlled (CNC) machine centres transform a stock piece of material into a finished product through a subtractive process. They are precision manufacturing machines that perform multiple advanced machining operations by manipulating tools around a varying number of axes. Machine centres perform specified instructions (G-code) inputted by engineers and machinists to produce a physical part from a computer design file. Automating the manufacturing process eliminates human error and reduces waste.
CNC machining centres also reduce production time by integrating multiple machine functions and can be seen as an all in one manufacturing tool. Machine centres are capable of producing high precision parts with a mirror-like surface finish by sequentially implementing drilling, milling and lathe operations. Previously, this production process was divided into individual working stages which required the operator to move the workpiece to a different machine tool at each stage. This resulted in an increased delivery time and overall production cost.
CNC machining centres are versatile machines used across many manufacturing industries to create parts such as gearboxes, bolts, frames, partitions, tools, brackets and models from a range of materials. These include aluminium, steel, plastic, foam, wood and titanium.
CNC machine centres utilise three conventional machining techniques. Each technique is performed with the purpose of removing material from a workpiece.
The first of which is drilling. A drill bit is spun at a preset rpm and moved into contact with the stationary workpiece. This creates holes and notches with precise diameters and lengths.
The second technique is lathing. A lathe is used as an inverse to drilling and the workpiece is spun against a stationary cutter to remove material in a circular path. Lathing is capable of turning, cutting, sanding, knurling, deformation and facing.
The third technique is milling. The milling process involves using rotary cutting tools to remove material from a stock piece. Milling is used to shaping, slot, drill and bore.
CNC machine centres and 3D printers are used to manufacture products as instructed by their input code, however, they differ in their application. CNC machine centres perform a subtractive process that removes material from a workpiece. Whereas 3D printing is an additive process that creates a product out of new material. Another difference is their overall production speed. CNC machine centres are faster and operate at much higher precision and accuracy.
A CNC Machinist is a highly skilled position that requires the operator to read and follow technical diagrams and have knowledge of CAM software. For this reason, operators must have 5 years of hands-on work experience in a tool making or engineering environment as well as a Fitter and Turner trade certificate and a completed apprenticeship. The Certificate III in Engineering – Fabrication Trade (MEM30319) is the recommended VET qualification to obtain the initial required skills to become a CNC machinist.
CNC machine centres are large industrial machines made of high-quality materials and are available in a range of specifications. The X, Y and Z axes specifications indicate the maximum travel distance of the motor. These specifications should be carefully considered when choosing a suitable machine as the workpiece must fit within the dimensions. Machine load is also another important machine specification.
X Axis (mm) | Y Axis (mm) | Z-Axis (mm) | Machine Load (kg) |
800 | 750 | 600 | 5500 |
650 | 1250 | 1000 | 5800 |
850 | 520 | 560 | 6000 |
1016 | 610 | 610 | 6800 |
The installation process of CNC machine centres requires careful planning and consideration. They are extremely heavy and precise machines with even the compact versions weighing over 2,000kgs. This requires the workfloor to be perfectly level and made of one solid slab. Improper placement may cause accuracy issues while in operation. It is also important to consider the power supply when installing a CNC machine. Some machines may require an electrical input that differs from other machinery. Finally, ventilation is another important aspect when installing the machine as excessive humidity can cause premature rusting.
Most popular CNC Machining Centre suppliers and brands on IndustrySearch are CNC Machinery Sales Australia, Applied Machinery, HACO Australia, Delahenty Machinery, Ron Mack Machinery Australia Pty Ltd, TJ Machine Tools Pty Ltd, Bliss & Reels, Absolute Machine Tools, AitalMAC Australia.