CNC Turning

CNC Turning is a manufacturing process in which bars of material are held in a chuck or collet and rotated while a tool is fed to the piece to remove material to create the desired shape. A turret, with tooling attached is programmed to move to the bar of raw material and remove material to create the programmed result. This is also called “subtraction machining” since it involves material removal. If the centre has both tuning and milling capabilities, such as the one below, the rotation can be stopped to allow for milling out of other shapes.

• The starting material, though usually round, can be other shapes such as squares or hexagons.
• Depending on the bar feeder, the bar length can vary. This affects how much handling is required for volume jobs.
• CNC lathes or turning centres have tooling mounted on a turret which is computer controlled. The more tools that that the turret can hold, the more options are available for complexities on the part.
• CNC’s with “live” tooling options, can stop the bar rotation and add additional features such as drilled holes, slots and milled surfaces.
• Some CNC turning centres have one spindle, allowing work to be done all from one side, while other turning centres, such as the one shown below, have two spindles, a main and sub-spindle. A part can be partially machined on the main spindle, moved to the sub-spindle and have additional work done to the other side this configuration.
• There are many kinds of CNC turning centres with various types of tooling options, spindle options, outer diameter limitations as well as power and speed capabilities that affect the types of parts that can be economically made on it.