Quality planning · Quality and production control
How to create an inspection plan for FDM parts
An inspection plan should not repeat every CAD dimension. It focuses on features whose deviation affects assembly, function, safety or interchangeability.
In brief
Every inspection feature needs target, allowed deviation, method, timing and reaction. Without a reaction rule, measurement is only an observation.
Derive features from risk
Inspection depth follows the consequence of failure.
- Start with assembly and fit dimensions.
- Inspect layer-critical load paths and thin areas visually or functionally.
- Assess purely cosmetic features separately.
Inspection definition
Equipment and fixturing must suit the feature.
- Dimension
- Caliper, micrometer, gauge or coordinate measurement
- Fit
- Functional gauge or real mating part
- Surface
- Defined visual inspection with lighting and distance
- Function
- Defined assembly or load test
Sampling and reaction
Sampling is meaningful only when process risk and batch size are considered.
- Inspect the first part before continuing production.
- Set different frequencies for stable and new processes.
- On deviation, contain the affected period and quarantine parts.
Printable template
FDM inspection-plan template
Complete one line per feature.
Feature and drawing reference
Target and tolerance
Method and equipment
Inspection point
Sample or frequency
Result record
Reaction to deviation
Responsible role