This is a 1:12 scale minifield of the FIRST Tech Challenge 2018-2019 Rover Ruckus challenge.
Everything is printed (the lander prints in 5 parts, the main body + 4 legs) except the tape, the silver minerals, and the outside walls.
We used airsoft BBs for the silver minerals since the printed ones didn't work for us.
For the walls, we used 1/8" polycarb (We think, it's the material used for the cyrptobox back from Relic Recovery) machined with a CNC, though it could be circular-saw'ed instead. If you'd rather print the walls, there's a file there for that as well.
Edit: 10/19/2018 - Included wall files for download .