Mazda MX-5 NC 16" / 56mm Centre Caps

I’ve spent a few weeks iterating and testing to get the fitment "just right" for these 56mm centre caps. Specifically designed for the 2008 Mazda MX-5 NC OEM alloys, I do consider these to be a good upgrade over the originals. I have tried some of the other 3D printed caps out there and found they just didn't fit, they were too brittle or had a massive overhanging lip.  

I've found designing the caps to be a good exercise in using Tinkercad and then switching to Fusion.

The Design & Functional Improvements

Getting 3D-printed clips to survive the road is the real challenge, so I’ve focused heavily on the mechanical side:

• Engineered Clips: Reinforced and redesigned for strength. They provide a secure fit—there is a tiny bit of play that allows the cap to rotate if moved by hand, but they are locked in and won't come out on the road.
• OEM Compatibility: I’ve included clip holes spaced approximately 38mm apart, so you might be able to swap in your original clips if you prefer.
• Removal Hole: There is a discreet centre hole integrated into the design. This allows you to use a small tool to pull the caps out without having to take the wheels off or risk marring your alloys with a screwdriver.
• Textured Aesthetic: Designed with a textured face to catch the light and hide the usual road grime and brake dust.
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⚠️ PLEASE NOTE: Logo Not Included

The "Flying M" (Bat variation) shown in the photos is a print I got from Thingiverse, I increased the height for a bit of 3D pop. The downloadable file is the centre cap base only. This gives you the freedom to add your own logos or emblems in your slicer.

Print Settings (Tested Results)

To achieve the finish seen in the photos, I used the following setup:

• Printer Hardware: E3D 0.4mm High Flow ObXidian Hot End.
• Layer Height: 0.12mm (essential for crisp logo detail).
• Initial Layer Height: 0.2mm.
• Walls: 3-4 loops minimum. Vital for the clips to have the correct tension and "spring" without snapping.
• Infill: 25% Gyroid.
• Supports: None needed if printed face-down.

Filament & Materials

For the ones in the photos, I used Tinmorry PETG Metallic in Red and Gold.

• Warning: Do not use PLA. Between the heat from the brakes and the UV exposure (even in the UK!), PLA will soften and you'll lose your caps on the first spirited drive. PETG is the minimum.

Fitting & Removal

1. Ensure the wheel hub is clean and free of grit.
2. Align the clips and push-fit until you hear a solid click.
3. To remove, simply use a thin hooked tool in the centre hole to pull the cap forward.

If you add your own logo to this base, please upload a photo of your make! I’d love to see what variations the community comes up with.

Note: This is a fan-created replacement part intended for personal restoration and repair. The Mazda logo is a trademark of Mazda Motor Corporation.