Cargo Buddy

The cargo buddy allows you to add a fitted elastic cargo-net over your backpack for on-the-go storage. 

Simply clip the 4 clips to the staps, thread the bungee through and secure it with the drawcord lock. 

Then use the netting needle to make your custom net.  that will tightly cover your bag. There are several ways to do this but the needle and sizing card method works well for me. 

then when you need storage, you can slip on the cargo buddies and stuff items under the net and cinch it down with the drawstring. 

I made this to use with my other model

https://www.printables.com/model/916587-net-hub-cargo-net-making-print

useful models to help you:

https://www.printables.com/model/176836-net-needle-net-shuttle

https://www.printables.com/model/201172-drawstring-brake-cord-lock

you will also need some 4mm round elastic cord and a backpack. 

note: 

The cargo-buddy has 2 intersecting holes. this means that you can pull the cord through at a 90-degree angle. Make sure that the forces are pulling the clip onto the strap, rather than off it. 

I printed this in PLA at 25% infill but I'd suggest you print at a high infill in a strong material e.g. PET with supports for the holes.