Targeting CNC gantry milling machine For controlling thermal stability, we employ tailored combinations of control strategies based on specific requirements to achieve the desired outcome.

　　1. Temperature differential control caused by air temperature and elevation differences

　　For temperature differences caused by ambient temperature fluctuations and elevation changes, the machine tool bed plays a crucial role. When the travel distances of the X‑axis carriage differ from those of the cross‑slide (Y‑axis) and the ram (Z‑axis), the first consideration is the machine tool’s installation location. The layout should be relatively independent, with adequate spacing between machines and sufficient distance from areas exposed to direct sunlight. The building height should be sufficiently high, and ventilation systems should be provided to enhance air circulation and help maintain thermal equilibrium.

　　If using a large CNC gantry milling machine For machining operations that demand high consistency and precision, the machine tool must be installed in a temperature‑controlled facility, which increases costs and raises the overall operating expenses of such equipment.

　　In addition, dynamic compensation can be implemented via the CNC system: after the machine is assembled and commissioned, multiple temperature sensors are installed at specific locations on the bed and crossbeam, while displacement‑measurement devices (such as laser interferometers) are used to assess the positioning accuracy of each axis at various temperatures. This allows for determining the required motion‑compensation values at each temperature‑sampling point under different temperature differentials. These compensation values are then fed into the CNC system, which compares the measured temperatures at the sampling points during operation to calculate the temperature differentials. By applying these differential corrections to each axis, significant improvements in accuracy are achieved. However, this approach places stringent demands on the selection of temperature‑sampling points, generates large volumes of compensation data that are difficult to analyze, requires advanced CNC capabilities, incurs high costs, and extends the production cycle. Consequently, it is suitable only for machine tools with specialized requirements—such as CNC gantry milling machines.

　　2. Heating Control for the Main Drive and Spindle Assembly

　　There are two common control methods for heating the main drive and spindle assembly: First, users are required to preheat the main drive system before machining—specifically, to start the spindle at the operating speed needed for the process and run it for approximately 30 minutes, allowing the machine tool’s main drive system to reach a state of relative thermal equilibrium. At this point, the thermal expansion and deformation of the machine tool’s saddle and spindle have stabilized, thereby… CNC gantry milling machine The impact on machining accuracy will not change significantly. At this point, machining operations can be carried out, thereby better ensuring the stability of machining accuracy. This method is also widely used today.

　　Secondly, constant‑temperature oil is used to cool the main drive and spindle systems, thereby reducing heat. This necessitates the addition of an oil cooler, which incurs some extra cost but delivers excellent results.

　　3. Control of Axis Motion Heating

　　On CNC gantry milling machines, such heating is primarily caused by the servo motor and the ball screw drive. These issues are particularly pronounced in small- and medium-sized CNC machine tools. To address servo motor heating, thermal insulation pads are typically used to isolate the motor’s heat, or cooling measures are added at the interface between the motor and the machine tool.

　　For heating in ball-screw drives, hollow‑screw circulating cooling oil is typically used to reduce the screw’s temperature, bringing it into thermal equilibrium with the machine bed and other major components. This ensures that the thermal expansion of the screw and the bed remains consistent, so that the screw’s preload, as well as the bearing preload, are unaffected by the heating process. Consequently, the drive stiffness of the feed axis is maintained across temperature variations, thereby enhancing the machining accuracy of the machine tool.