Pint Size Combine Tractor Really Works

David O'Brien, Harvard, Ill., spent "countless" hours planning and building a "pint size" Deere 7720 combine for his kids.

The built-to-scale project was the second of its kind for O'Brien who has also built a Deere 8850 4-WD tractor to scale. Both projects were built from the ground up and both can be driven around the farmyard just like the real thing.

The mini combine, powered by a 4-hp Briggs & Stratton pull-start engine, features variable ground speed, throttle, brake, a centrifugal clutch, movable unloading auger, a grain platform that raises and lowers, variable speed reel that turns via ground drive when the platform is down, a drive differential, and tilt wheel steering for operator comfort. It's got a top speed of 5 to 6 mph but can be sped up for parades by changing sprockets.

O'Brien fabricated the body of the combine from sheet metal working to 1/4 to 1/5 scale of a full-size 7720. Once finished, he painted the machine "Deere green" and applied Deere equipment decals.

O'Brien's mini tractor was also built from the ground up with brakes and a tow hitch for pulling wagons and other things around the farmyard. It features front and rear duals, articulating steering, oscillating differentials, fenders, hitch, "sound guard" cab, lights, clutch, brake throttle, chrome stack, seating space for two, and a Briggs & Stratton engine. Like the mini combine, it also features tilt steering.