Box Cutter - Key Chain Sleeve Mod

We have seen lots of printed box openers that you can attach to a key ring. How about using the actual key ring as the cutter because it will never break or wear out?

Depending on your ring you can cut pretty thick cardboard with it.

This design serves as a sleeve for a standard 25mm diameter, 2mm thick key ring. Print it in TPU with fuzzy skin for grip. Only takes between 5 and 1

0 minutes on most printers. The base is flat for good adhesion. No supports necessary as the inside roof is curved. 

The sleeve has some clearance so it is easy to rotate the ring. If you have a larger key ring you can simply scale it up.

Instructions

1. Bend out one end of the key ring which will serve as your blade. 
2. Slide the other end into the sleeve, keep going until it is all inside
3. When you need to use it rotate the ring so the end of the ring is unsheathed - the more it is unsheathed the better cutting action you have. Cut, then rotate the ring back into the sleeve for protection. DONE.

3DJake does not recommend sharpening one end of the ring with a dremel to make it into a deadly weapon but that would be cool.