Question those blades aren't sharp are they? .. they are used to just till the ground right... looks like the edges are
turned under... again great idea... what made you think of those?
They are kind of sharp. Not like a razor blade but they will cut you if you run your hand across the edge. Actually one of the reasons I had to remake the bases because the gas station that welded the first ones welded one disk on upside down (they were flat ones not curved like these ones) and I could just see myself walking up to them at night or in the house barefoot and cutting my toe on them.
I got the idea for using the disc blades a few years ago when I contacted my teacher asking if he knew of anyone who could make a stand for me. He ended up having me call up a guy he knew and he suggested using one of those discs. He was also going to make them for me too but I ended up having a hard time finding them and it took a few years to find some discs I could afford so I ended up having to make them myself.