Table of Contents

Step Field Reference

For the complete and up-to-date field reference, see MachiningStep.

To assess the risk of tool breakage, also refer to "Evaluating Process Machinability".

This page summarizes the main output data for each simulation step, covering source line, kinematics, load, force/torque, power, thermal, and wear information to help quickly understand the machining state at each step.

Step data contains information for the time interval between two consecutive steps (i.e., from the previous step to the current step). Many fields are therefore simplified representations over that period. Common prefixes based on the simplification method include Average (Avg), Extremes (Min, Max), Range (Delta), and Maximum Absolute Value (MaxAbs).

Basic Source Information

  • FileNo / LineNo / FilePath / LineText / FlagsText: File/line information and flags of the corresponding source NC command.
  • StepIndex: Step sequence index.
  • ToolId: ID of the currently active tool.

Time and Motion

  • EndTimecode: Simulated end-of-step timecode (formerly AccumulatedTime; step CSVs written with the legacy header are still read).
  • StepDuration: Duration of this step (default per-revolution mode: one step equals one spindle revolution).
  • BeginSpindleAngle_deg: Spindle angular displacement at the start of this step.
  • Cl (Cutter Location): Cutter location point (including IJK normal).
  • MC (X, Y, Z, A, B, C): Machine coordinates.
  • MoveOnProgramCoordinate, MovingLength_mm: Displacement vector and length in the program coordinate system.
  • Feedrate_mmdmin / SpindleSpeed_rpm / CuttingSpeed_mmds: Feed rate, spindle speed, and cutting speed.
  • FeedPerTooth_mm / FeedPerCycle_mm / ToothArcDuration_s / SpindleCyclePeriod_s: Feed per tooth/per cycle, tooth arc duration, and spindle cycle period.

Cutting Engagement and Material Removal Rate

  • IsTouched: Whether cutting engagement occurred.
  • CuttingWidth_mm (ae) / CuttingDepth_mm (ap): Cutting width / cutting depth.
  • Mrr_mm3ds: Material removal rate.
  • ProgramSideCusp_um, SideCuspList_um: Side cusp height and distribution estimated from program feed and radius.

    Reading tip — a ProgramSideCusp_um spike usually flags a rapid-move (G00) collision, not a finish result. The program-side cusp is computed from the ideal program feedrate while the cutter is engaged with the workpiece. A rapid traverse is not meant to touch material; when it does, the cusp formula is fed the (very high) rapid feedrate, so the value spikes far above any real cutting cusp. Treat an isolated cusp peak at a rapid/G00 line as a likely gouge/collision to investigate. The same engagement-during-rapid usually shows up alongside it as spikes in the availability ratios (yielding-stress / spindle-torque / spindle-power).

Chip

  • ChipThickness_mm (/um): Chip thickness.
  • ChipVolume_mm3: Chip volume.
  • ChipMass_mg: Chip mass.

Force and Torque (Including Mapping Comparison)

  • Coordinate system note: Most fields in this section indicate their coordinate system (e.g., [W] workpiece, [TR] tool running, [SR] spindle rotation). For coordinate system definitions and diagrams, see "Milling Physics Coordinate Systems".
  • AvgForceToToolOnToolRunningCoordinate_N, MaxAbsForce_N: Average/maximum force.
  • Various average/maximum torques (about tool tip, about sensor point; in tool running / spindle rotation / workpiece program coordinate systems).
  • AvgAbsTorque_Nm: Average absolute torque.
  • Mapping comparison: AvgMomentXyByMapping_Nm, AvgAbsTorqueByMapping_Nm, error ratios, and symbolic error correlation metrics.

Power, Torque, and Energy Consumption

  • SpindleInputPower_W (input power): Energy entering the spindle.
  • SpindleOutputPower_W (output power): Energy acting on the cutting end after spindle energy losses — i.e., the energy causing workpiece and chip deformation and temperature change. Output power is typically proportional to input power, with the ratio being the energy efficiency set in the spindle configuration EnergyEfficiency(API).
  • MaxSpindlePowerRatio (maximum spindle power ratio): Input power / instantaneous maximum power based on spindle capability.
  • ContinueSpindlePowerRatio (continuous spindle power ratio): Input power / unlimited-duration maximum power based on spindle capability.
  • AccumulatedSpindleEnergyConsumption_kWh: Accumulated spindle energy consumption.
  • Max/Continue Spindle Torque Ratio: Instantaneous/continuous spindle torque ratios.

    Reading tip — a power / torque ratio over 100% means the spindle cannot supply the demanded load at the commanded rpm, so it droops: with feed held, rpm drops, feed-per-tooth rises, and forces climb further — a runaway loop that, left unchecked, grows the chip until the cutter breaks and the spindle/drive is overstressed and damaged — load damage, not a tool-vs-workpiece collision (see NC optimization). Read it by duration, not just height: a one-revolution (single-cycle) overshoot usually still completes the pass — it just leaves a slightly insufficient cut there — whereas a ratio that stays above 100% across many consecutive spindle revolutions is a genuine overload to fix. A high-load step typically also shows large cutter–workpiece engagement (CWE), large tip deflection, and more vibration/noise. Because the ratio is normalized by the spindle-capability curve, a placeholder/guessed spindle skews it — confirm against the real spindle's speed–power/torque curve before calling it overloaded.

Thermal and Temperature

  • CutterBodyTemperature_C / CutterDermisTemperature_C / WorkpieceDermisTemperature_C / ChipTemperature_C: Cutter body, cutter surface, workpiece surface, and chip temperatures.
  • GetCutterDermisTemperature_C(depth_mm) / GetCutterDermisAvgTemperature_C(depth_mm): Cutter subsurface temperature / average temperature at a given depth.
  • ThermalStress_MPa / ThermalYieldRatio: Thermal stress and thermal yield ratio. For tool breakage risk assessment based on thermal yield ratio, see "Evaluating Process Machinability".

Wear and Deflection

For wear models, evaluation metrics, and applicable scenarios, see "Tool Life and Wear".

  • InstantCraterWear_um / AccumulatedCraterWear_um: Instantaneous/accumulated crater wear.
  • AccumulatedFlankWearDepth_um / AccumulatedFlankWearWidth_um: Accumulated flank wear depth/width.
  • Tip/Edge Deflection (um): Tool tip and bottom edge deflection (including maximum and delta values), as well as ReCutDepth_um (re-cut depth).