Ingmars klyv II, Human-powered DIY wood splitter
Yes, the splitting maul and axe also are human-powered but this is a machine that appears to be doing it with a lot less effort and much safer.
The machine does most of the work, but the operator is in total control, with no fuel, no noise (except the wood cracking), and pretty low budget, both on funds, and labor.
The wood splitter is entirely created from scrap that the maker seems too have had laying around his property and thus it has cost him very little to any in funds.