'Shipping Crate' case for 6045 multi-rotor propellers

This thing is a cool little carrying case for my 6 inch by 4.5 pitch props for my 280 Versa Copter from FliteTest.com The case holds 8 props on 2 posts. There is a little bit of space around the posts in case some people have props with smaller bores in the center hub. I designed this with the intention of just putting a rubber band around the box to keep the top on, but it turned out to be a very light friction fit where the crate top fits down around the posts. If it loosens up over time,