iPhone Case with Integrated Bike Mount
Designed and 3D-printed a functional iPhone case with integrated dovetail bike mount interface. Features parametric CAD modeling, dual-material approach, and optimized TPU print settings.
Skills
Overview
Designed and fabricated a functional iPhone 11 case that balances protection with an integrated bike mount system. The case features a dovetail interface compatible with existing bike mounts, enabling secure hands-free phone mounting while cycling.
The design required careful consideration of Apple’s MagSafe compatibility, screen protection, and button accessibility while maintaining the structural integrity needed for bike mounting.
Design Features
MagSafe Compatibility
1.8mm back wall thickness preserves iPhone MagSafe functionality while providing impact resistance and keeping the camera module flush
Screen Protection
3.5mm front lip extends over the edge onto the inactive bezel without interfering with touchscreen functionality
Dual-Material Approach
Flexible TPU 90A case with rigid PLA drop-in dovetail insert for dimensional stability and secure mounting
Parametric Design
Key dimensions maintained as parameters in Fusion 360 for rapid iteration and tolerance adjustments
Bike Mount Interface
The primary functional feature is a dovetail interface integrated into the back of the case, mating with an existing bike-light mount. The dovetail was designed as a separate PLA drop-in component rather than printed directly into the TPU case for two key reasons:
- Dimensional stability — PLA provides higher stiffness and more consistent fit than flexible TPU
- Print quality — Keeping the dovetail separate ensured a flatter, cleaner base print for the TPU case without overhangs
The PLA insert was iteratively designed through test prints, adjusting clearances by tenths of a millimeter to achieve a smooth sliding engagement with a snap-fit locking mechanism.
Final assembled phone case with PLA dovetail insert
Manufacturing
Material: PolyFlex TPU 90A — selected for softness, flexibility, and ease of installation while maintaining durability
Print Settings:
- 240°C extruder temp (above recommended range for smoother flow)
- 60°C bed temp for better adhesion
- 18% infill with gyroid pattern for compliance and material efficiency
- Supports enabled for front lip and camera cutout
The flexible TPU allows the case to absorb impacts and flex around tight geometries, while the parametric CAD model enabled rapid iteration on fit and tolerances.