I designed a propellor storage box which will also be able to print on smaller sized printers like my old Turnigy Fabrikator which has a max print size of 15x15x10 cm. (will need supports inside which are hard to remove so larger print volume is recommended.)
It contains a bottom section which has 2 seperate compartments for cw and ccw props and a lid that slides firmly in place so it stays closed.
The size of the case is the same size as the original cardboard one, except the height. It's a bit longer but will still fit in the backpack.
I've added the top and bottom seperately and also removed the tabs from the bottom half. they seemed to do more harm than good.
If you want you can print the bottom of the case 2% smaller (or lid 2% bigger) this way it closes better since it's a pretty tight fit
you can also upscale the height (z-axis) about 2% if you want the lid to fully close. the props are a bit longer than the inside size!!!
It can hold the originals as well as the carbon Maytechs. See the last picture on how to fit them.
The bottom gave some problems in simplify 3d so I've replaced it with a fixed version.
If you can print it standing up straight you obviously don't need supports.