Analysis of CNC Turning-Milling Machines and Multi-Axis Systems
Since its invention in the 1950s, the CNC lathe has secured a significant place in human history and machinery. The introduction of this tool has enabled us to produce various sizes of parts. With the advent of independent electric motors, lathes have become more advanced, offering higher reliability and power while occupying less space. As machines have become increasingly complex, G-code has replaced the punched tape system.
A lathe operates through a combination of slides and screws. Typically, a standard lathe is composed of X and Z axes and can perform two-axis simultaneous turning (as shown in the diagram below). Such systems have existed for a long time and still hold a crucial position in manufacturing. However, with technological advancements, turning alone can no longer meet users' needs. The evolution of electronic and automotive parts has led to more complex components and higher precision requirements. Consequently, milling capabilities have been integrated with turning in a single machine, transforming the turret from a standard servo turret to a milling-capable power turret.
Initially, basic turning-milling machines consisted of X/Z/C axes. The C-axis, combined with an encoder, allows for precision up to one-thousandth of a degree, enabling milling operations with a power turret (as shown on video: https://www.youtube.com/watch?v=MKt6hbJjcw4 at 0:42).
Since 2000, Y-axis lathes have been available. The so-called Y-axis lathe, which you can read about in a previous article (https://www.mylascnc.com/data-67483), is faster and more accurate than the C-axis lathe, saving significant time.
Despite these advancements, they still could not meet consumers' demands for the highest precision and mass production. This led to the emergence of dual-system turning-milling machines. These machines feature two sets of X/Z/Y axes on a single lathe, allowing for two different programs to be run on the controller simultaneously, akin to operating two machines at once (but on a single machine). This capability allows for the processing of more complex parts and speeds up the production process.
Processing more complex parts is possible due to the multi-axis lathe, which can be equipped with two tool turrets, increasing the number of tools available. The dual system also allows for back machining with a sub-spindle, processing the backside of the workpiece (as seen in the video: https://www.youtube.com/watch?v=g_P9lsasxks at 1:12), and enabling simultaneous upper and lower turret operations on a single part (as shown in the diagram below), reducing machining time by 30-50% or more.
Are there machines beyond dual systems? Yes, there are. Machines can extend to 6-8 systems, as seen in INDEX of Germany or TORNOS of Switzerland, which have developed multi-spindle lathes with over six systems, greatly increasing machining speed. In extreme cases, highly complex parts can be machined in under ten seconds, whereas traditional turning-milling machines might take 60 seconds or more.
Currently, our most advanced lathes feature three systems with axes X1/Z1/Y1/X2/Z2/Y2/X3/Z3. Combined with dual turret mechanisms, these lathes are sufficient for general machining needs. Our self-made tool holders can enhance the dual turrets to function similarly to three turrets, offering substantial machining capabilities.