DOI: 10.5281/zenodo.16579803
title: Large scale machine tool axes heating data: 49 thermocouples, 14 Integral Deformation Sensors

description: The dataset published here includes numerous variables of a large scale machining centre registered during axes heating tests.

The dataset is divided in two independent files, one containing external sensor variables, and the second one, with internal CNC variables, as exposed in the corresponding sections. The combined dataset enables detailed correlation between internal variables and structural sensor readings, supporting thermal modelling, digital twin synchronisation, and machine health diagnostics.

Main characteristics of the machine

RLLLR configuration: Rotary table (C axis), XYZ linear axes and tilting head (A axis).

Travel ranges of 1630, 1310 and 1500 mm in X, Y and Z axes respectively, -135o to 45o tilt on A axis, and infinite rotation capacity in C axis.

Milling head: 84 kW with maximum speed of 12,000 rpm.

Turntable: 54.1 kW with maximum speed of 500 rpm capable of milling.

Sensor Dataset

File: SensorData6To8November2024.xlsx

This dataset consists of sensor data acquired from a CNC machine tool over a non-continuous period from November 6 to 8, 2024, with a sampling frequency of 1 Hz. The file contains a total of 65 columns, each corresponding to a specific variable recorded during machine operation, and is structured in a single-sheet spreadsheet.

The first column, Date, records the timestamp in ISO 8601 format (yyyy-mm-dd hh:mm:ss) for each sample, representing the local date and time of acquisition (GMT+1). The second column, Timestamp, is a UNIX-style epoch counter in seconds, which provides an absolute time reference useful for synchronisation purposes.

Columns Bar_01 to Bar_14 correspond to readings from Integral Deformation Sensors (IDS bars) installed at various structural locations of the machine. These values are expressed in micrometres (µm), representing thermally induced deformation along the measurement direction for each IDS device.

The remaining columns, Thermocouple_01 through Thermocouple_49, correspond to temperature measurements (in degrees Celsius, °C) taken by thermocouples distributed throughout the machine structure and moving components. These include locations such as spindle housings, guideways, motor mounts, and other key thermal masses influencing geometric stability.

Each row in the file thus represents a time-synchronised snapshot of thermal and structural deformation conditions across the machine. This comprehensive dataset enables the analysis of spatially distributed thermal gradients and their relation to structural deformation, easing model training, validation, or data-driven thermal compensation approaches.

CNC Internal Variable Dataset

File: CNCVariables6to8November2024.xlsx

Complementing the external sensor dataset, this file contains internal diagnostic data collected from the CNC control system and embedded sensors of a SINUMERIK 840D sl machine tool. The data acquisition was performed over the same period (November 6 to 8, 2024) and with a sampling frequency of 1 Hz. The dataset includes 41 columns that represent real-time internal states and physical variables monitored by the control system. It must be noted that each day, readings of this dataset may start or end at different times than the sensor dataset, as consequence of the different switching on and off delays of the equipment used for collecting data, but timestamps and dates are directly comparable.

The first two columns, Date and Timestamp, provide temporal information. Date corresponds to the local time in ISO 8601 format (yyyy-mm-dd hh:mm:ss), while Timestamp contains the UNIX epoch time (in seconds), enabling synchronisation with external sources.

The remaining columns report on variables associated with the machine’s linear and rotary axes (X, Y, Z, A, C), as well as the main spindle. For each axis, the following variables are provided:



      [Axis]PositionActual (mm or degree depending on axis): current axis position measured by the encoder or optical scale.

      [Axis]Speed (rpm or mm/min depending on axis): actual axis or spindle speed.

      [Axis]Load (%): current torque/load as percentage of rated value.

      [Axis]Power (kW): power consumption estimate for each drive.

      [Axis]Intensity (A): current drawn by the axis motor.

      [Axis]Temperature (°C): temperature reading from the internal motor sensor.


Global machine state variables are also recorded:



      ControllerMode (integer): operating mode of the control (e.g. JOG, AUTO, REF).

      ExecutionState (integer): execution status of the part program (e.g. STOPPED, RUNNING, HOLD).

      SPActualSpeed (rpm): current spindle rotational speed.

      SpindleOverride and PathFeedrateOverride (%): real-time override settings for spindle and feed.

      PathFeedrateActual (mm/min): effective feedrate commanded at each sample.