ISO 10791-6:2014

Overview

ISO 10791-6:2014 - "Test conditions for machining centres - Part 6: Accuracy of speeds and interpolations" specifies kinematic test methods to verify the accuracy of spindle speeds, feed rates, and interpolated motion of numerically controlled (NC) machining centres. It applies to machines with three linear axes (X, Y, Z) plus one or two rotary axes (A, B or C) and references ISO 230‑1 and ISO 230‑4 for measurement principles and circular tests. The standard addresses only kinematic accuracy (not dynamic behavior such as vibration or noise) and is intended for acceptance, comparison, commissioning, and maintenance checks.

Key topics and technical requirements

• Scope and applicability
  • Machines with 3 linear axes and 1–2 rotary axes; five‑axis configurations are covered via Annexes A–C.
  • Tests may be applied partially or wholly by agreement between manufacturer and user.
• Kinematic tests (Clause 5)
  • K1 - Spindle speeds: checks deviation of spindle speed at midpoint and maximum of each range, both clockwise and counterclockwise (example tolerance shown: ±5%).
  • K2 - Feed speeds: verifies commanded feed vs actual feed through the control-to-kinematic chain.
  • K3 - Linear interpolation: checks coordinated motion of two linear axes (e.g., 45° and small-angle conditions).
  • K4 - Circular interpolation: verifies circular path accuracy where axes change speed and direction; ISO 230‑4 referenced for circular test methods.
• Five‑axis and rotary-axis tests
  • Annex A, B, C define tests for machines with rotary axes in the spindle head, on the workpiece side, or with swivel heads/rotary tables; include tests for tool-centre-point (TCP) behavior.
• Measurement practice
  • Use of appropriate measuring instruments (e.g., revolution counters, stroboscopes, displacement sensors); sampling frequency and instrument uncertainty must be reported.
  • Linear units in millimetres, angular units in degrees (or microradians/arcseconds when needed).
• Software compensation
  • Use of built‑in compensation is allowed only by agreement and must be reported in test reports.

Practical applications and users

Who uses ISO 10791-6:

• Machine tool manufacturers (design verification, acceptance testing)
• OEMs and production shops (acceptance, procurement, commissioning)
• Test laboratories and metrology teams (certified kinematic testing)
• Maintenance and quality engineers (diagnostics, performance validation)
• Integrators and end users negotiating acceptance criteria

Typical uses:

• Acceptance tests for new machining centres
• Contractual performance specifications in procurement
• Commissioning and troubleshooting of CNC motion and TCP functions
• Periodic verification for quality assurance and calibration programs

Related standards

• ISO 230‑1 Test code for machine tools - Geometric accuracy (installation & measuring methods)
• ISO 230‑4 Test code for machine tools - Circular tests for NC machines
• ISO 230‑7, ISO 841 and other parts of ISO 10791 (Parts 1–10) for complementary geometric and performance tests

Keywords: ISO 10791-6, machining centres, accuracy of speeds, interpolations, spindle speed tests, feed speed tests, linear interpolation, circular interpolation, five-axis machining, TCP.