The assembly of CNC turn-mill machines is similar to that of CNC lathes, but it is more complex.

The differences are as follows:

1. Spindle

The spindle in a turn-mill machine has an encoder, a brake disc, and a brake. The encoder allows the C-axis to achieve angle resolutions as precise as one-thousandth of a degree. The brake disc prevents slippage during C-axis operations, ensuring greater precision.

2. Turret

Unlike conventional lathes, the turret in a turn-mill machine is a power turret with milling capabilities. It includes an additional motor for milling operations and typically accommodates more tools (12/16/20 tools). It can also perform semi-indexing, increasing the number of tool positions.

3. Number of Axes

Turn-mill machines have more axes compared to traditional lathes. Basic configurations include:

     - X/Z/C-axis lathe

     - X/Z/C/Y-axis lathe

     - X/Z/C/Y/X2/Z2/Y2 and potentially more

More axes mean greater versatility, allowing the machine to perform more complex operations.

4. Controller

Turn-mill machines typically use high-end controllers such as Fanuc's Oi TF Plus or 31i/32i series. These controllers support more motors and offer enhanced capabilities, including larger program memory, faster speeds, and advanced functions like skiving and beveling.

5. Precision

Turn-mill machines achieve higher precision compared to conventional lathes. This is due to the elimination of secondary loading processes, such as additional milling or back-side machining.

6. Footprint

While turn-mill machines occupy more floor space than conventional lathes, they take up significantly less space than a separate lathe and milling machine combined.