This week’s selection is the Floating Buoy Keychain by MakerWorld contributor spookycromch.
This is a classic design of the week: a simple, easy-to-print and highly functional item. It’s designed to keep your keys afloat, should they accidentally fall into water.
In a Reddit post, spookycromch explains:
“Recently I was out on the water and having my keys without some kind of floating keychain made me nervous. I’ve seen foam-like boating keychains sold in hardware stores, but I decided to make my own. 3D-printed objects are usually surprisingly light anyway – should work perfectly!”
3D prints are indeed light because they are mostly hollow. I typically use 15% or less for infill density, meaning it’s 85% air. That air is buoyant in water, so long as there are no leaks.
That’s the big question on this design: would it leak? It absolutely would if one used spiral/vase mode and had a single wall. However, it’s possible to do some tricks to make it watertight:
- Print with many perimeters (three recommended)
- Raise the extrusion temperature
- Heat the build chamber
- Print with a material that is self-sealing
- Seal with epoxy after printing
You could also consider using an infill pattern that forms isolated air pockets, like the Titanic had — although in this case we would hope for a better outcome.
The result is a keychain that indeed floats, as demonstrated here by spookycromch:
According to their calculations, the keychain should be able to float while carrying up to 35g. That should be more than sufficient for a couple of keys.
Spookycromch also suggests the possibility of scaling up the keychain to increase its buoyancy, which would be easy to do.
The 3D model has been uploaded to MakerWorld, where it is free for anyone to download.
Via MakerWorld and Reddit
