Spring cord lock

Use case

I needed this cord lock to hold the little storage sack closed that protects my GoPro in my motorbike luggage. It is made for 3mm paracord. Of course the printed spring is not ultimately strong, but it is good enough to stop the sack from opening. 
Update 16.1023: After a lot of experimenting, I was able to come up with a much better printed spring. Here it is: https://www.printables.com/model/617291 As this publication was part of a contest, I leave it here in the original form, as it was for the contest. 

Printing

Printing this design is actually very easy. No supports or brim are needed. Just print all parts in the uploaded orientation. As the parts or so tiny, all it takes are 4 perimeters and they will be strong. The used material for the inner and the outer round part is not critical. But for the spring you need to used PETG to get the needed springiness. 

Please like it if you like it

Your satisfaction is my reward. Please give me a like if you enjoy this design.

Happy printing!