Coordinate Measuring Machine Restraint Fixture Calibration for Thermoplastic Assemblies
Calibrate CMM restraint fixtures by matching datum locators to nominal CAD and regulating clamping forces to eliminate non-rigid part deflection.
Clamp Force Calibration
Meaning
Systematic verification procedure ensures that the actual tonnage exerted by the injection moulding machine matches the value shown on the controller. Regular clamp force calibration prevents damage to the mould and minimizes the risk of part flash. Load cells or strain gauges are used to measure the force during the closing cycle.
Load Verification
Displacement of the tie bars under tension provides a direct measurement of the locking force. When clamp force calibration is performed, the sensors detect whether the press is applying even pressure across the platens. Uneven loading leads to premature wear on the bushings and guides.
Machine Accuracy
Hydraulic and electric systems can drift over time due to component wear or sensor degradation. Because clamp force calibration identifies these discrepancies, the operator can adjust the settings to maintain process consistency. A machine that reports ten percent more force than it delivers will produce inconsistent parts.
Conversely, excessive force can crush the vents in a tool or cause the platens to bow. The calibration process involves testing the machine at several points across its entire range. This data forms a baseline for future maintenance schedules.
Process Stability
Consistent clamping is a prerequisite for a stable moulding window. Without accurate clamp force calibration, the transition between machines becomes difficult. Quality parts require a repeatable environment.