Hi folks. A fabricator/farmer friend and I are discussing developing a prototype for an open-source tractor. We would like it to be narrowly focused on organic farming field work. The concept is to offer an alternative to the aging Alice Chalmers Gs and Farmall Cubs which need considerable maintenance or repair and are rising in price, while dropping the financial barrier to access as far as possible, making it more affordable and more tailored for agricultural use than an Open Source Ecology Farm Trac (which is truly inspiring, but likely overkill for the goals/tasks envisioned here).
What features would you look for in such a tractor? What sort of crop clearance would you need for cultivation? What sort of wheel spacing would you need for your beds? What mounts would you like for implements - front, rear, and/or belly? Would hydraulic lifting for these implements be necessary? Would the value of PTO power or auxiliary hydraulics warrant their additional cost? What would your horsepower needs be, considering the implements you anticipate using? What are the most important considerations for you in selecting a new tractor or replacing a current one? What problems presented by current equipment would you most like to see addressed?
We are preliminarily envisioning a 2WD tractor with hydraulic wheel drive, steerable front wheels, and hydraulic implement lifting capability, powered by a 27HP gasoline utility engine. The design would prioritize providing the operator with an excellent view of any belly or front-mount implement. We have also discussed skid-steer 4WD concepts. In either case, the hydraulic wheel drive motors would likely be mounted remote from the wheels in order to provide adequate crop-clearance underneath the tractor, and drive them remotely via drive chains or ribbed high-strength belts.
If hydraulic lifting cylinders were not necessary, costs could likely be cut down considerably, as my initial research indicates that a traditional or hydrostatic rear transmission/differential unit could cost considerably less than the hardware required for a hydraulic system. There are likely a large number of off-the-shelf hydrostatic transaxles available given their use in lawn tractors.
I welcome your thoughts and contributions!