Objective & Scope
Establishing a consistent measurement protocol is the foundation of quality control in 3D printing. This instruction outlines the necessary steps to ensure that physical parts align with their digital counterparts. We focus on identifying critical dimensions, selecting the appropriate tools, and accounting for the inherent variations of the FDM process. Whether you are working on a simple enclosure or a complex mechanical assembly, following these guidelines prevents assembly failures and ensures long-term repeatability.
Technical Protocol
The measurement process requires a clean environment and calibrated instruments. Before starting, ensure the part has cooled completely to room temperature, as thermal contraction can skew results by several microns. The protocol follows a systematic approach to capture external, internal, and depth-based features.
- Zero your digital calipers or micrometers before every measurement session to eliminate offset errors.
- Apply consistent pressure when closing the jaws on the part to avoid deforming the plastic surface.
- Take at least three readings for each critical dimension and record the average to account for surface texture.
Verification Criteria
Compare your findings against the original CAD specifications. A part is considered "in-spec" if it falls within the defined tolerance range, typically ±0.1mm for standard FDM prints. If the part exceeds these limits, document the deviation and analyze potential causes such as over-extrusion, shrinkage, or improper cooling. Consistent documentation allows for fine-tuning of slicer settings in future iterations.