Overview
ISO 13041-8:2004 - Test conditions for numerically controlled turning machines and turning centres: Part 8 - provides standardized test procedures for the evaluation of thermal distortions in NC turning machines and turning centres (up to 2 000 mm in length). The document defines three targeted thermal tests (environmental temperature variation, rotating spindle, and moving linear axes), references ISO 230-3 for detailed test code and measurement practice, and specifies required instrumentation and reporting formats. The standard does not assign numerical tolerances; it focuses on repeatable methods and data presentation for acceptance, commissioning and diagnostic purposes.
Key topics and requirements
- Scope and reference: Applies to NC turning machines and turning centres ≤ 2 000 mm; testing procedures are to be applied with reference to ISO 230-3.
- Three defined tests
- Environmental Temperature Variation Error (ETVE) test - evaluates machine response to ambient temperature changes; duration minimum 4 h (extendable up to 24 h if drift continues); recommended to run with controls OFF when required.
- Thermal distortion from rotating spindle - tests thermal effects caused by spindle operation; typical procedure uses a variable speed spectrum (e.g., speed/stop cycles) and lasts 4 h plus 1 h with the spindle stopped.
- Thermal distortion from moving linear axes - evaluates thermal effects caused by axis motion; follows ISO 230-3 procedures and normally lasts 4 h.
- Measuring instruments: Linear displacement probes, temperature sensors, test mandrels, data acquisition systems; for moving-axis tests a laser interferometer (or bidirectional probes) can be used with precautions per ISO 230-1.
- Reporting and recordkeeping: Standardized tabular and graphical result formats are specified; detailed test metadata must be recorded (manufacturer, serial number, sensor locations, thermal compensation method, spindle speed regime, warm-up and preparation procedures, etc.).
- Flexibility: Tests may be used individually or in combination; choice of tests for acceptance must be agreed between user and supplier.
Applications and users
- Practical uses:
- Acceptance and commissioning of NC turning machines and turning centres
- Factory acceptance tests (FAT) and site acceptance tests (SAT)
- Preventive maintenance, troubleshooting and performance verification
- Specifying acceptable thermal environments and thermal compensation strategies
- Typical users:
- Machine tool manufacturers and suppliers
- Quality, maintenance and metrology engineers in manufacturing plants
- Test laboratories and third-party inspectors
- Procurement teams specifying machine performance criteria
Related standards
- ISO 230-3:2001 - Test code for machine tools: Determination of thermal effects (normative reference)
- ISO 230-1:1996 - Geometric accuracy of machines (relevant for laser interferometer precautions)
- ISO 13041 (other parts) - Geometric and performance tests for NC turning machines
Keywords: ISO 13041-8:2004, thermal distortions, NC turning machines, turning centres, ETVE test, spindle thermal distortion, moving linear axes, ISO 230-3, machine tool testing, laser interferometer, thermal compensation.
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