which is under-construction at a blacksmith workshop of a friend. This 3' tiller is sensitive to the trees, or to other obstacles. It automatically shifts to the other side when the curved pipe on the right side of the tiller hits a tree and goes back its original position after it passes the tree. That is, this has a mechanical feedback system. Building the farm implements at home is not a heavy / hard task unless you are a lazy person. Why pay much $$$$ for such simple objects.