Overview
When a family heat pump stopped working, the issue turned out to be a broken plastic gear in the intake grille mechanism. Instead of replacing the whole unit, I reverse engineered the gear and 3D-printed a replacement part to bring the system back online.
My Role
- Disassembled the front grille and identified the failed gear.
- Measured the original part and recreated it in CAD with correct tooth profile and dimensions.
- Selected print settings and material, printed prototypes, and iterated on the design.
- Installed and tested the new gear in the unit.
Tools & Technologies
- Software: CAD (Fusion 360 / FreeCAD), slicer software
- Hardware: FDM 3D printer, basic hand tools
- Skills: measurement, tolerance design, mechanical troubleshooting
Key Challenges
- Getting the tooth profile and clearances right so the gear meshed smoothly with the existing mechanism.
- Choosing material and print orientation that would hold up to repeated cycles and minor load.
- Working inside a confined HVAC housing without damaging other components.
What I Learned
- How to quickly design and iterate a functional replacement part for a real system.
- The value of combining basic mechanical troubleshooting with digital fabrication.
- That small, inexpensive fixes can prevent much larger replacements and waste.