Here is a fully parametric Gridfinity bin designed for holding smartwatch bands. Most designs store bands on their sides, but I wanted a layout that makes them easier to see and access.

The gridfinity bins in this set are created using Gridfinity Boxes Filled-In (Fusion 360) by Spike_Mix, 

Gridfinity Boxes Filled-in (Fusion 360) - Free 3D Print Model - MakerWorld, I then designed the parametric inserts to hold the watch bands.

You can stack bands a couple high if needed, or print multiple bins—these are fully stackable as well.

Sizing tips:

• Band length: Measure the full length of your band. For rigid bands (like metal or clasp-style), use their total laid-flat length.
• Band width:
  • ~36 mm for 42–49 mm Apple Watch bands
  • ~33.5 mm for 38–41 mm Apple Watch bands
• Height:
  I recommend using a 3u or 6u bin height, with ~12 mm allocated for the band height. This gives enough clearance to slide bands in easily, and thinner fabric bands can stack two high.

And if you want a nice logo added in the Bambu Slicer, go ahead and search for SVG Apple Watch Logo, and insert it as a modifier, 0.4mm on the surface.

If you print one, I’d love to see it—please consider leaving a review with a picture! Feedback and suggestions are always appreciated.