Kinematic Restraint Fixturing Mechanics for Injection Molded Thermoplastics Metrology
Kinematic restraint fixturing isolates molded thermoplastic part geometry by arresting six spatial degrees of freedom without introducing bending strain.
Datum Target Simulator
Meaning
Physical components represent the theoretical datums of a part during the inspection process. A datum target simulator contacts the surface of a workpiece at specific points or areas to establish a coordinate system for measurement. It bridges the gap between the perfect geometry of a digital model and the irregular surface of a manufactured part.
These tools are necessary for verifying that a prototype meets its dimensional requirements.
Fixture Precision
Mechanical accuracy in the construction of the gage ensures that the measurement reflects the actual condition of the part. A datum target simulator must be harder and more stable than the material it measures. Regular calibration prevents wear from introducing errors into the inspection data.
Constraint Strategy
The way a part sits in the gage dictates which degrees of freedom are restricted. Designers use a datum target simulator to replicate the assembly condition of the component in the final product. Three points define the primary plane while two points set the secondary axis.
This setup allows the inspector to measure the location of holes relative to the functional features. If the simulator is designed incorrectly, the part might wobble or sit at an angle. Such errors lead to false rejections of good parts.
Correct placement of the contacts ensures the repeatability of the metrology run.
Metrology Interface
Spheres or flat pins touch the surface at the locations defined by the drawing. The datum target simulator provides the fixed reference for the coordinate measuring machine.