Process planning · Process and manufacturing decisions
How to plan finishing for FDM parts
Finishing is useful when it creates a named function that the raw print cannot reach economically. It should be defined before orientation and quoting, not improvised after printing.
In brief
Finish only faces and features that need it functionally or visually. Geometry, allowance, access, workholding and inspection size must be planned together.
Functional finishing
Dimensions and joints are the most common reasons.
- Hole
- Drill or ream to final size
- Thread
- Insert, captive nut or cut thread by load case
- Seal or datum face
- Face machining only with suitable workholding and allowance
- Assembly
- Bond, screw or mechanically interlock
Cosmetic finishing
Visual quality takes time and can alter dimensions.
- Keep cosmetic faces away from supports during orientation.
- Agree sanding and filling against a defined target appearance.
- Mask fits and identification before painting.
Avoid planning errors
Many finishing problems arise from missing access or unsuitable wall thickness.
- Provide tool access and workholding faces in CAD.
- Set allowance by feature, not universally.
- Inspect final size after the last property-relevant step.