Meaning
Mechanical constraints define how a part is supported during measurement to eliminate degrees of freedom without introducing unwanted deformation. A kinematic boundary layout utilizes six points of contact to establish the exact position and orientation of a moulded component. This method ensures that the inspection results reflect the true geometry of the part.
Constraint Logic
Three points define a primary plane, two points define a line and one point defines a stop to fully arrest the movement of the object. Within a kinematic boundary layout, each contact point is placed strategically to minimize the deflection caused by gravity or clamping forces. Plastic parts with thin walls are especially sensitive to how these points are distributed.
Repeatability Factor
Hard fixtures can hide warpage if the part is forced into a shape it does not naturally hold. Using a kinematic boundary layout allows the part to sit in its free state, revealing the actual shrinkage patterns of the resin. This transparency is necessary for validating the accuracy of the injection mould and the cooling cycle.
Metrology Application
Software often simulates these physical contacts to align scan data with a digital model. This digital implementation ensures that the measurement results are comparable across different laboratories and inspection sessions. Precise contact points prevent the introduction of bias during the analysis of flexible polymer parts.
