I present my O-Ring Ring; designed to hold two "Glow In The Dark" o-rings (not included) in the slots that run around the ring's band.
This model has been designed for printing in Plastic, Aluminium, Brass, Bronze, Silver, Gold, or Platinum if you're feeling adventurous.
The sizing of this ring model is 29.7mm internal diameter, a UK T 1/2 (US 10).
The design can be scaled up and down indefinitely, but the o-rings are only available in certain sizes and will only work on a certain range of ring sizes.
If you would like a specific size then please send me a message.
The required o-rings have a 1.5mm cross-section diameter and come in 20 and 24mm outer diameters. They can be purchased from dx.com, in bags of 20, for less than 3 dollars.
The 20mm o-rings are suitable for rings sized US11 and below, while the 24mm o-rings cater for rings that are a US11 or above. However below a US6, the 20mm o-rings may not be able to be compressed into the channels anymore, while above a US15, the 24mm o-rings may become over-stretched.
20mm o-ring: www.dx.com/p/glow-in-the-dark-water-tight-silicone-o-ring-seal-20mm-20-pack
24mm o-ring: www.dx.com/p/glow-in-the-dark-water-tight-silicone-o-ring-seal-24mm-20-pack
This ring is just one of many ring designs I have created. As well as making the ring bodies available on Shapeways, I can also offer fully assembled tritium and glow rings. Please contact me if any of the other designs take your fancy, or you would like an assembled ring.
There are some more photos of this object and other examples of my work, both 3D printed and otherwise, on my 'Tofty' facebook page.