I made to this to clean out between garden rows and help smooth the kart track. I used 1/2 inch round stock for the spikes. The frame is made out of 1-1/2 square tubing that someone gave me.
Buddy of mine upgraded his setup and sold me his old one cheap because he knew I needed a good welder. It been 6 years since I tried welding with a mig. Second picture is my second try. I also already fixed the murray kart with it.