| From August 2005 issue of Successful Farming, pg 38-39. |
This self-propelled cart is worth half the
capacity of another combine
Able to travel 12 1/2 mph in the field and 28
1/2 mph down the road, Oftedahl Farms'
self-propelled cart also provides great visibility
in the field. Photographs by Howard Mohr.
capacity of another combine
Able to travel 12 1/2 mph in the field and 28
1/2 mph down the road, Oftedahl Farms'
self-propelled cart also provides great visibility
in the field. Photographs by Howard Mohr.
Over 200,000 bushels later, Oftedahl Farms' homebuilt self-propelled grain cart has become a lead
weapon in their arsenal to shoot down harvest bottlenecks. "We figure it is like having another half of a
combine at work," Tom Oftedahl says, referring to the fact that the cart allows their combine to operate
longer between stops.
Fast and dependable
This grain gazelle also handles like a dream in the field, racing from the combine to waiting trucks at
speeds that lap tractor-drawn grain carts. And after over 250 hours of use, the self-propelled cart has
yet to break down. "People say it doesn't look homebuilt," says Oftedahl, who farms with his partners,
sister Julie and brothers Wayne and Mark, near Hanley Falls, Minnesota.
Design and construction on the cart began in December 2003. Long before that, Oftedahl began having
issues with their aging grain wagon. For one thing, the farm's tractor operators were unable to accurately
monitor the auger position during unloading into the semitrailers. The Oftedahls wanted transport that
different workers could easily "unload without dumping part of it on the ground on the other side of the
truck," Oftedahl says.
weapon in their arsenal to shoot down harvest bottlenecks. "We figure it is like having another half of a
combine at work," Tom Oftedahl says, referring to the fact that the cart allows their combine to operate
longer between stops.
Fast and dependable
This grain gazelle also handles like a dream in the field, racing from the combine to waiting trucks at
speeds that lap tractor-drawn grain carts. And after over 250 hours of use, the self-propelled cart has
yet to break down. "People say it doesn't look homebuilt," says Oftedahl, who farms with his partners,
sister Julie and brothers Wayne and Mark, near Hanley Falls, Minnesota.
Design and construction on the cart began in December 2003. Long before that, Oftedahl began having
issues with their aging grain wagon. For one thing, the farm's tractor operators were unable to accurately
monitor the auger position during unloading into the semitrailers. The Oftedahls wanted transport that
different workers could easily "unload without dumping part of it on the ground on the other side of the
truck," Oftedahl says.
| The rear axle, fashioned from 2×4×1D4-inch tubing, hosts a four-speed gearbox and final drives from a Deere combine. |
A series of hydrostatic pumps provides total
hydraulic control and operation of the cart.
hydraulic control and operation of the cart.
Locating the cab
Positioning the cab took the most guesswork and debate. "We went round and round discussing how
high it should be," Oftedahl recalls. "We settled on making it as high as we could. My shop door is 12
feet. The top of the cab is 11 feet 10 inches. The top of the box is 4 inches lower than the cab."
Prior to uniting all the components, Neisius arranged for an engineer, Greg Rude of Solid Design
Consulting, to do a weight-and-balance computation. Oftedahl and Neisius were fairly sure they had
designed the cart to have appropriate weight distribution and center of gravity. "We knew we would be
real close. This was just insurance to see that it was done right," Oftedahl adds.
All the cart components were weighed, and their locations on the future cart were entered in Rude's
computer, which created a virtual picture of the machine. A full analysis showed the cart's center of
gravity was within safe limits to prevent tipping backward during acceleration.
After it was assembled last August, the cart received its only trial, which "wasn't much," Oftedahl recalls.
"Basically, we drove it up and down the road a few times. After that it was used to help a neighbor with
his wheat harvest with no problems."
That's when Oftedahl discovered one of the cart's hidden talents - visibility. "An operator can easily see
the combine and the cart's box for on-the-go unloading," he explains.
Visit Successful Farming Website.
Positioning the cab took the most guesswork and debate. "We went round and round discussing how
high it should be," Oftedahl recalls. "We settled on making it as high as we could. My shop door is 12
feet. The top of the cab is 11 feet 10 inches. The top of the box is 4 inches lower than the cab."
Prior to uniting all the components, Neisius arranged for an engineer, Greg Rude of Solid Design
Consulting, to do a weight-and-balance computation. Oftedahl and Neisius were fairly sure they had
designed the cart to have appropriate weight distribution and center of gravity. "We knew we would be
real close. This was just insurance to see that it was done right," Oftedahl adds.
All the cart components were weighed, and their locations on the future cart were entered in Rude's
computer, which created a virtual picture of the machine. A full analysis showed the cart's center of
gravity was within safe limits to prevent tipping backward during acceleration.
After it was assembled last August, the cart received its only trial, which "wasn't much," Oftedahl recalls.
"Basically, we drove it up and down the road a few times. After that it was used to help a neighbor with
his wheat harvest with no problems."
That's when Oftedahl discovered one of the cart's hidden talents - visibility. "An operator can easily see
the combine and the cart's box for on-the-go unloading," he explains.
Visit Successful Farming Website.
Tom Oftedahl (pictured) had help creating his monster cart
from friends Paul Neisius and Troy Zieske.
from friends Paul Neisius and Troy Zieske.
Salvaged components
From the beginning, Oftedahl, the lead engineer in the project, knew he had no choice but to use recycled
components to keep costs down on the cart. The finished machine evolved from components salvaged
from three different combines, a sprayer, a truck, and logging equipment.
The only item the farm bought new was a Parker Model 524 wagon for its 500-bushel box. Even that box
was modified with the addition of 2-foot-tall sideboards, which boosted its capacity to 700 bushels.
The first item salvaged was the cab from a burned-out New Holland TR86. The remainder of the used
components were acquired later, with the help of Tjosfold Implement, a New Holland dealer in nearby
Granite Falls.
Oftedahl received much help in the cart's design from friend and neighbor Paul Neisius, who owns a
welding and fabrication business on his farm. Plus, Troy Zieske of SunSource custom-designed the cart's
hydraulic system. "The cart wouldn't be what it is without those two guys," Oftedahl says.
Creating the frame
Neisius fashioned the cart's frame from 4×12×1/4-inch steel tubing. The steering axle was cut from a
portion of the rear axle of a junked New Holland TR96. The frame for the rear axle and box is
2×4×1/4-inch tube. The engine is mounted on a frame made from 4×2×1/4-inch tubing. Gussets and
supports are made from 1/2×4-inch steel.
Power for the cart comes from a Caterpillar Model 3208 salvaged from a New Holland TR70 combine.
Three hydraulic pumps in decreasing sizes are mounted in series on the engine. A heavy-duty pump
nearest the engine was salvaged from logging equipment and powers the cart's hydrostatic drive. The
second pump powers the unloading auger.
A third pump provides pressure for steering and auger movement.
Oftedahl added a second hydrostatic drive to increase the cart's ground speed by around 30%, giving the
vehicle up to 12 1/2 mph in the field and 28 1/2 mph on the road. The hydrostatic drive works through a
four-speed gearbox, drive axle, and final drives salvaged from a Deere 8820 combine.
From the beginning, Oftedahl, the lead engineer in the project, knew he had no choice but to use recycled
components to keep costs down on the cart. The finished machine evolved from components salvaged
from three different combines, a sprayer, a truck, and logging equipment.
The only item the farm bought new was a Parker Model 524 wagon for its 500-bushel box. Even that box
was modified with the addition of 2-foot-tall sideboards, which boosted its capacity to 700 bushels.
The first item salvaged was the cab from a burned-out New Holland TR86. The remainder of the used
components were acquired later, with the help of Tjosfold Implement, a New Holland dealer in nearby
Granite Falls.
Oftedahl received much help in the cart's design from friend and neighbor Paul Neisius, who owns a
welding and fabrication business on his farm. Plus, Troy Zieske of SunSource custom-designed the cart's
hydraulic system. "The cart wouldn't be what it is without those two guys," Oftedahl says.
Creating the frame
Neisius fashioned the cart's frame from 4×12×1/4-inch steel tubing. The steering axle was cut from a
portion of the rear axle of a junked New Holland TR96. The frame for the rear axle and box is
2×4×1/4-inch tube. The engine is mounted on a frame made from 4×2×1/4-inch tubing. Gussets and
supports are made from 1/2×4-inch steel.
Power for the cart comes from a Caterpillar Model 3208 salvaged from a New Holland TR70 combine.
Three hydraulic pumps in decreasing sizes are mounted in series on the engine. A heavy-duty pump
nearest the engine was salvaged from logging equipment and powers the cart's hydrostatic drive. The
second pump powers the unloading auger.
A third pump provides pressure for steering and auger movement.
Oftedahl added a second hydrostatic drive to increase the cart's ground speed by around 30%, giving the
vehicle up to 12 1/2 mph in the field and 28 1/2 mph on the road. The hydrostatic drive works through a
four-speed gearbox, drive axle, and final drives salvaged from a Deere 8820 combine.
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