I recently fabricated a unique implement to make processing my firewood 100% mechanized. After a little thought I realized that this would be a perfect tool for gathering wood for rocket mass heaters because it it is intended for smaller wood. In my case it was designed to make use of wasted wood, saplings that grow on the edge of my fields, saplings from pre-commercial forestry thinning, and from the land clearing that I do (on my farm as well as for hire).
The problem I ran into was, these small trees take a lot of time to gather up because being smaller, it takes many of them. So my idea was, make it a mechanized process. So I came up with this homemade feller-buncher. It mounts to my log loader and allows me to sever a tree from the stump, then load it onto my log trailer for the trip back to my house.
It really is a two machine process: use the feller-buncher to cut, gather and haul the wood, then build a firewood chunker (Rebak Machine) to process the wood into chunks automatically. That will make my firewood 100% mechanized. At present I have enough saplings on the margins of my fields to last me many years. Anyway, here is my homemade feller-buncher.
His brain is the size of a cherry pit! About the size of this ad: