Big A Converted To High Boy Crop Sprayer
Howard Ewen turned a worn-out Big A fertilizer spreader into an adjustable row-width, high boy sprayer. By adjusting the wheelbase a few inches, he can switch from 24 38-in. rows to 30 30-in. rows and back or stay narrow for road transit, all on the go.
“I was planning to build a sprayer when my son heard about a Big A that needed a new engine and front wheel,” recalls Ewen. “I made a low-ball offer, and they took it. We narrowed the front fork, replaced the engine with a 238 Detroit diesel and adapted it to take a 6-speed Allison transmission.”
That, of course, was just the start. Ewen completely replaced the back end of the spreader from the transmission back, including legs for the drive wheels. He used the rear end of a Chevy truck with air brakes and turning brakes. He also used a mechanical final drive system from a Deere 7700 combine. He mounted them in legs he fabricated to give the sprayer extra clearance.
A telescoping toolbar connects the rear drive wheel legs to the Big A frame. Ewen used 8-in. angle iron to fabricate 8 by 8-in. channel iron.
“When you have salvaged angle iron that costs half a cent per lb. versus 25¢ per lb. for channel iron, you make do,” says Ewen.
Hydraulic cylinders can adjust the toolbar by 16 in. on a side to match the row or road width. Adjusting the driveshafts was more complicated as they needed to telescope with the toolbar. Ewen had splines cut into the leg ends of the shafts and used splined drive sprockets at the top of the legs.
In order to provide for future wear on the drives, the shafts connect to the Chevy rear-end hubs via universal joints. Ewen fabricated half the universal joint directly on the short stubs extending out of the Chevy hubs, mounting the other half to the splined shafts.
The shafts power the triple #80 chain drive to the wheels. At the hub end of the leg, Ewen made an adapter plate for the hub so he could mount IH tractor wheels for a narrower tread.
Another change Ewen made was to install a combine cab in place of the Big A cab. It provided better visibility and had air conditioning.
“I used a boom system from an old Hagie sprayer and parts of the Big A boom,” says Ewen. “Each section has a Redball spray monitor on it with a separate hose to each nozzle and cylinder on each section so I can lower or raise it or the boom ends.”
The sprayer pump, hydraulic pump, and engine shaft all run off of a countershaft. Ewen says he went with a mechanical drive rather than hydrostatic so it's easier to keep the pressure up while slowing down or speeding up at row ends. A combination of gear ratios, sprocket sizes, and transmissions gives him a spraying speed of about 8 mph and a road speed of 14 mph.
“I had several pages of calculations on gear ratios and wheel circumferences in order to figure out field speeds,” says Ewen. “I worked on it for about 3 years. You put that much time and energy into something without knowing if it'll work. The first time I took it to the field, it handled like a dream. Sitting up high on it is like riding in a cloud.”
Contact: FARM SHOW Followup, Howard Ewen, Jr., 6997 W State Rd. 8, Lacrosse, Ind. 46348 (ph 219 754-2365)
Big A Converted To High Boy Crop Sprayer SPRAYING Miscellaneous Howard Ewen turned a worn-out Big A fertilizer spreader into an adjustable row-width high boy sprayer By adjusting the wheelbase a few inches he can switch from 24 38-in rows to 30 30-in rows and back or stay narrow for road transit all on the go “I was planning to build a sprayer when my son heard about a Big A that needed a new engine and front wheel ” recalls Ewen “I made a low-ball offer and they took it We narrowed the front fork replaced the engine with a 238 Detroit diesel and adapted it to take a 6-speed Allison transmission ” That of course was just the start Ewen completely replaced the back end of the spreader from the transmission back including legs for the drive wheels He used the rear end of a Chevy truck with air brakes and turning brakes He also used a mechanical final drive system from a Deere 7700 combine He mounted them in legs he fabricated to give the sprayer extra clearance A telescoping toolbar connects the rear drive wheel legs to the Big A frame Ewen used 8-in angle iron to fabricate 8 by 8-in channel iron “When you have salvaged angle iron that costs half a cent per lb versus 25¢ per lb for channel iron you make do ” says Ewen Hydraulic cylinders can adjust the toolbar by 16 in on a side to match the row or road width Adjusting the driveshafts was more complicated as they needed to telescope with the toolbar Ewen had splines cut into the leg ends of the shafts and used splined drive sprockets at the top of the legs In order to provide for future wear on the drives the shafts connect to the Chevy rear-end hubs via universal joints Ewen fabricated half the universal joint directly on the short stubs extending out of the Chevy hubs mounting the other half to the splined shafts The shafts power the triple #80 chain drive to the wheels At the hub end of the leg Ewen made an adapter plate for the hub so he could mount IH tractor wheels for a narrower tread Another change Ewen made was to install a combine cab in place of the Big A cab It provided better visibility and had air conditioning “I used a boom system from an old Hagie sprayer and parts of the Big A boom ” says Ewen “Each section has a Redball spray monitor on it with a separate hose to each nozzle and cylinder on each section so I can lower or raise it or the boom ends ” The sprayer pump hydraulic pump and engine shaft all run off of a countershaft Ewen says he went with a mechanical drive rather than hydrostatic so it s easier to keep the pressure up while slowing down or speeding up at row ends A combination of gear ratios sprocket sizes and transmissions gives him a spraying speed of about 8 mph and a road speed of 14 mph “I had several pages of calculations on gear ratios and wheel circumferences in order to figure out field speeds ” says Ewen “I worked on it for about 3 years You put that much time and energy into something without knowing if it ll work The first time I took it to the field it handled like a dream Sitting up high on it is like riding in a cloud ” Contact: FARM SHOW Followup Howard Ewen Jr 6997 W State Rd 8 Lacrosse Ind 46348 ph 219 754-2365
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