Backpack Buckle

- If you made this thing and are happy with it I kindly ask to give it a shout!

Update Apr. 23rd
Could be well combined with http://www.thingiverse.com/thing:2267793

I recently got an Assassins Creed backpack which I love dearly.
Getting and keeping it closed was an awkward thing, though.
The upper end is to be rolled up and the strap over it was held in place with a
velcro strap which got weak early. Heavily laden with all the food I need at work
it always came loose once I had it on my back and took a breath.

This buckle replaces the velcro, snaps smooth in place and is released by turning
the outer ring some 60° to the left.

Additionally needed is
6 x M3 nuts and screws (8-10 mm, depending on the thickness of your belt or whatever)
4 x spiral springs from a ballpen

Print all parts and two of the latches with 0,1 mm and 20% infill which prooved
to be quite sturdy. All parts are printing well without supports. Only for the buckle you
need to determine yourse