Self-Propelled Sprayer Does 40 On The Road

Self-Propelled Sprayer Does 40 On The Road SPRAYING Miscellaneous 28-2-16 Carl Larson loses no time between fields with his shop built self-propelled sprayer, that speeds down the road at up to 40 mph. Fuel economy is good, too, since he replaced the initial Chevy gas engine with a Perkins diesel. Now he can spray 150 acres on 18 gal. of fuel, triple what he could do with the original Chevy engine. "I couldn't maintain good ground speed with the Chevy either," says Larson, a Leonardville, Kan. area farmer. "I put the Perkins in gear, set the throttle and it stays where I set it." He started out with a 1975 1-ton Chevy truck chassis. Its 4-speed transmission with 2-speed transfer case gives him the low-range gears needed for spraying. Although it has front wheel drive, he never uses it, pointing out that if he needs it, conditions aren't right for spraying anyway. After stripping away the body and cab, he reinforced the frame, boxing in the back end to strengthen it to carry a 500-gal. tank. "If I was doing it again, I would make the whole frame from rectangular tubular steel," says Larson. "I would also raise the tank a little higher at one end or put a sump on it for better clean out." While the chassis had a good set of springs under it, Larson added air bags to help carry the weight. He increased crop clearance to 24 in. by replacing the truck wheels with rear wheels from a John Deere combine. He had to re-dish the rims and weld in new centers to fit the Chevy axles. The cab came off a 1460 International Harvester combine and is rubber mounted to the chassis. The flip hood was made by cutting down the rear section of a 715 International Harvester combine. Air is drawn from a salvaged combine preclean filter mounted to the cab roof. The 354 cu. in. Perkins engine came out of a Massey Ferguson combine by way of a neighbor's Chevy Suburban. "J.C. Whitney had an adapter kit that let him bolt the Perkins to the Chevy transmission," explains Larson. "He sold it to us with the kit, ready to go." Matching the truck front axle to the combine steering system required replacing the truck's drag link with a hydraulic cylinder. The hydraulics handle the torque of turning the loaded rig on soft soil, while torsion bars added in front stop front axle twisting. Larson also installed a catwalk around the tank and a centrifugal pump with electric clutch for the spray unit. A fresh water tank allows him to clean out the spray tank in the field. He built 3-section booms from 1 1/4-in. tubing on the bottom side with 2-in. rectangular tubing on the top, with gussets in a V shape and all nylon tubing for hoses. The outside 12 ft. on the 60-ft. booms are able to "break away. The mast is all that remains of the original booms. "I added hydraulic valves to raise and lower the boom from 3 ft. off the ground up to 4 1/2 to 5 ft. high," says Larson When he first built the sprayer, Larson hooked up a 12-volt foam marker. Later he adapted an air pump off a truck with air brakes to deliver foam. Last year, he added a satellite guidance system. "That takes the guesswork out of it," he says. "I still use the foam as backup for turning at the end rows." Contact: FARM SHOW Followup, Carl Larson, 14091 LK&W Road, Leonardville, Kan. 66449 (ph 785 293-5714).

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