Google’s recently announced $99 Fitbit Air fitness tracker is already on open sale, and it just got a neat addition for DIY fans. Google released the official Fitbit Air design guidelines featuring the tracker’s exact dimensions, tolerance margins and 2D CAD files (PDF), so you can 3D print custom bands and accessories.
The guidelines come with exact mating dimensions, tolerances and specifications for attach and detach force. Fitbit Air is comprised of two key components, with the “pebble” housing the sensors, batteries and key components, as well as the “sleeve,” which wraps around the pebble and attaches to the bands.
Fitbit Air 2D CAD drawings
Google’s guidelines specify that all bands and accessories need to offer appropriate sensor clearance for the heart rate and SpO2 sensors so that they remain unobstructed. Google also recommends consistent skin contact between the tracker and choosing skin-friendly materials for the bands.