Compact Key Holder with swivel lock

This is a compact key holder that features a friction captured swivel locking mechanism.

I have seen various swiss army style key holders, but I don't like that they don't keep the keys in place when your screws lose tightness causing loss of friction due to wear from daily use. The locking mechanism in this design is to prevent keys from swinging out even with no friction on the keys.

While this compact design may not be able to accommodate a large amount of keys, it was created with some very specific functions for up to 5 keys.

Design considerations:

Swivel lock mechanism
* Captured by friction of the shorter prong onto the frame. (see photo)
* Easily opens by pushing on the side nub to overcome the friction then pull on the long tab in the front.
* Keys are pushed out of the shell when swivel opens for easy access to keys.
* Keyring is attached to the swivel to leverage gravity on the keys to naturally keep it in the closed position.
* Keyring is positioned to prevent the swivel from swinging too far.

3-keys version
* Use M3x12mm bolt with 3mm round head
* Use M3 hex nut (2mm thick)

5-keys version
* Use M3x16mm bolt with 3mm round head
* Use M3 hex nut (2mm thick)
* 5-keys is with no spacers or washers
* 4-keys with washers/spacers
* Accommodates keys up to 50mm length from key ring eyelet
* 0.4 mm washer between keys for less friction
* 1mm spacer for stacking to use as spacers
* typical key thickness is 2 spacers (2mm)
* Washers…