This is a minimalist key chain for storing rings. Useful when doing work that could be dangerous when wearing a ring, or if you don't want to get your ring dirty. This makes a great everyday carry item as it's roughly the size of the ring itself so it takes up very little room in your pocket.

The snap ring that I used can be found on Amazon, but similar ones will likely work. You can also adjust the dimensions of the snap ring in the Fusion 360 file.

The ring is held in place by the snap ring that is used to attach it to the key ring, this makes it so that this one small printed part is able to hold the ring in such a way that it is impossible to fall out. The slot is designed such that there is nominal clearance between the ring and snap ring to prevent wear between them from rubbing. The part also protects the exterior of the ring so it isn't damaged by anything in your pocket when used. On the wedding band design, I've also included two small cutouts on the bottom to make it easier to pop out the ring when done with it since I found with my rectangular cross sectioned ring it has a tendency to “friction fit” in the slot.

Customization

The nature of rings makes it such that this will likely not fit your ring directly. I've included Fusion 360 files that are parameterized and can be edited to fit most wedding bands. For the engagement ring holder, my design will likely not work since it's extremely customized to fit my partner's ring snugly. I've included it as reference though if you'd like to make something similar.

Wedding band parameters:

• RingOD: Outside diameter of ring
• RingID: Inside diameter of ring
• RingHeight: Height of ring
• CaribinerOD: Outside diameter of snap ring
• CaribinerID: Inside diameter of snap ring
• LengthTol: Tolerance factor that is multiplied by the ring dimensions to ensure fit. In my case I used 101%
• HoleTol: Tolerance factor that is multiplied by the carabiner dimensions to ensure fit in hole. In my case I used 105%

Print Parameters Used

I printed this on my Creality K1 with a 0.4mm nozzle and using Inland Glass Purple filament. To increase the print quality I used the variable layer height setting in Orcaslicer to thin out layers around the fillets and holes to make them smoother.

Inspiration

Design inspired by Lion Latch, but I wanted something that was a single part and much smaller for everyday carry on my keyring.