Turning is the machining operation that produces cylindrical parts. In its basic form, it can be defined as the machining of an external surface, with the workpiece rotating, with a single-point cutting tool, and with the cutting tool feeding parallel to the axis of the workpiece and at a distance that will remove the outer surface of the work. Live cross drilling & milling tools sequentially engage to produce complex shapes and forms automatically.
What is CNC Turning?
CNC Turning Process
Similarly to CNC Milling, the turning process begins with the creation of a CAD (Computer Aided Design) part design and exporting this into a file which the machine recognises. The engineer can use this CAD file to generate the code required for the machine to operate and make any changes to the cutting speeds required for the component being machined.
The operator then has to setup the lathe, by securing the raw material into the chuck (which holds the parts during the whole machining process) and loading the tool turret (which can hold many tools at once). The turning process can have many steps so the right tooling has to be selected to achieve the required finish.
The tools and raw material have to then be calibrated correctly to ensure the required tolerance and quality is upheld, before uploading the program to begin the cycle.
Once running, the raw material is spun (turned) as a set RPM, and the selected tools move into position to remove the required amount of material, and to bore out any holes. This is determined by the program setup, which has the following parameters:
- Spindle Speed – this is the number of rotation per minute (RPM) of the material turning in the spindle
- Workpiece/Raw Material Diameter – The thickness of the material determines the correct cutting speed
- Cutting Speed – This shows the relative speed of the workpiece compared to the cutting tool
- Feed Rate – This shows the distance the cutting tools move per one full turn of the workpiece/raw material
- Axial/Radial Cut Depth – These are the depth of the cuts on the different axes. Higher feed rates put pressure on the cutting tools.
Dependant on the final desired shape of the component, hexagonal or cylindrical bar can be used to remove the need for any secondary machining or milling operations.