I made it in my Wood & Metal Structures class in school as my "Student Project." My teacher got me a 1"x12"x8' board and a 1"x12"x12' board to make the sheep feeder with. It's definately not perfect, but it should serve it's purpose and it should be super strong (look at all those screws!) It is supposed to be raised off the ground, but we (my friend and I) couldn't make the corner posts long enough so that way we'd have enough wood for the entire project. So my solution would be to put it on two bales of straw or set it up on some cinder blocks. I also didn't put any boards on the bottom for support, nor any plywood triangles on the top.
Anything that touches a corner needs to be cut at an 18* angle to make it all fit together nicely. It's only about 2 feet tall and about 3 feet wide at any of its widest points.
Based off of this plan.
Hopefully it will be put into use soon And maybe if I build another one it will look much better than my prototype