86% of all the worlds farms are less than 2 acres in size. These farms are typically low income (roughly $1500/yr) and often find expensive machinery that would improve their yield (and accordingly, their profits) unattainable. Addressing this need can reduce food scarcity, global poverty, and a substantial value chain for smallholder farms, machinery manufactures, maintenance service providers and more. An affordable small tractor would offer income stability and independence to the farmer.

This GEAR Center project presents a novel tractor architecture to enable mechanization of small farms in India where farms are conventionally serviced with draft animals. Farmer's prefer draft animals for their compact dimensions, high maneuverability, and low capital cost. The “Bullkey” (the name given to GEAR Lab’s new vehicle design) seeks to combine the benefits of bullocks and conventional tractors, leaving their drawbacks behind.

The first Bullkey prototype proved that 2 wheeled, motorcycle-format tractors are more powerful than draft animals and outperform other, conventional tractors by weight. It was capable of primary and secondary tillage, planting, intercultivation and spraying - all needs identified through discussion with farmers and other agricultural stakeholders in India - and was well received by farmers in the US and abroad.

Recently, the vehicle was completely overhauled with a redesigned frame, new spraying systems a complete, integrated hydraulic system, power-take-off and new, compact plow and three-point-hitch systems. This work was part of a new focus on refining the Bullkey architecture to maximize the vehicle's utility and build a competitive, marketable product. New consultation with smallholder farmers, mechanics and other stakeholders yielded new design insights. The system was tested at a local Massachusetts farm, and GEAR Center researchers traveled to India and interviewed over 130 farmers about the Bullkey tractor and how it would fit into their farming practice. The GEAR Center is currently exploring options for commercializing this technology.

Peer-Reviewed Journal Articles

Investigation of viability to replace draft animals with all-wheel-drive motorcycles on small farms
Diaz Lankenau, G. F., and Winter V, A. G., ASME Journal of Mechanical Design (2021) || download

Design of a specialized tractor to replace draft animals in small farms
Diaz Lankenau, G. F., and Winter, V. A. G., ASME Journal of Mechanical Design (2020) || download

An Engineering Review of the Farm Tractor's Evolution to a Dominant Design
Diaz Lankenau, G., & Winter, A., ASME Journal of Mechanical Design (2019) || download

Peer-Reviewed Conference Articles

Design of a Human-Powered Roll Stabilization Attachment for Utilitarian Two-Wheeled Vehicles.
Diaz Lankenau, G.F., Daigle, L., Ihns, S.H., Koch, E., Saadi, J., Tornes, P., Wu, J.M., and Winter V, A.G., Proceedings of the 21st International Conference on Advanced Vehicle Technologies, ASME IDETC/CIE, (2019) Anaheim, California.

An Engineering Review of the Farm Tractor’s Evolution to a Dominant Design.
Diaz Lankenau, G.F., Winter V, A.G., Proceedings of the 44th Design Automation Conference (DAC), ASME IDETC/CIE, (2018) Quebec City, Quebec, Canada

Proof-of-Concept Evaluation of a Low-Cost and Low-Weight Tractor for Small-Scale Farms
Arelekatti, V. N. M., Björkdal, D., Graves, C., Wong, A., Mkrtchyan, A., & Winter, A., ASME IDETC/CIE (2014)

Theses

Design of a market-ready tractor for small farms in low- and middle-income countries

Collin Goldbach, Master’s Thesis (MIT, September 2023)

Tractor design for small farms in resource limited markets
Diaz Lankenau, G.F., PhD Thesis (MIT, Feb 2020)

The mechanics of tractor performance and their impact on historical and future device designs
Diaz Lankenau, G.F., Master's Thesis (MIT, 2017)