News

Aug 06, 2023

$15K grant to help Marion farmer convert Farmall into dual

MARION, Wis. – Bob Braun, a retired Technical College Automotive Instructor, utilizes a combination of 20th-and 21st-Century technology to operate his grass-based farm in northern Waupaca County,

MARION, Wis. – Bob Braun, a retired Technical College Automotive Instructor, utilizes a combination of 20th-and 21st-Century technology to operate his grass-based farm in northern Waupaca County, where he raises poultry, goats and cattle.

Many of his tractors and other implements were new in the 1950s and ‘60s, but he also has a 10-kilowatt solar system, with an array of solar panels on the roof of his shop that powers lights, refrigerators and freezers, the well pump and other equipment on his farm.

Braun’s background and interest in solar technology led him to successfully apply for a $14,957 grant from the North Central Region Sustainable Agriculture Research and Education Program that he’s using to convert a gasoline-powered Farmall M to a hybrid dual-fuel tractor that will enable the tractor to perform necessary chores on the farm, while saving gasoline.

“I’ve been thinking of applying for grants for a decade,” said Braun. “The biggest driver for me was once I got the solar system which is producing some serious power, I wanted to utilize solar to power some machinery which was running off gas or diesel. Currently, I’m making 8.37 kilowatts of electricity and sending 5.5 back into the grid.”

He had thought about buying a new electric tractor but saw a significant weakness. “The only ones I’ve seen that were really successful were Allis Chalmers G’s with electric drive, but they’re basically a utility cultivator tractor for market gardens, which is a more controlled environment,” he explained

“From driving my Prius, I began thinking that maybe I could have the best of both worlds by adding electric power to the gas engine,” he said. “I’ve been around a lot of electric cars and know the technology, and thought about making a hybrid. And I have all that electric power.”

After receiving the grant in March, Braun began converting a 1951 gas-powered Farmall M that he has used for many tasks in the farm's daily operation to a hybrid configuration.

The tractor previously had been updated with hydraulics and a three-point hitch, and is now being modified with a modern electric motor that will be powered by onboard batteries.

A friend was able to source an electric motor for Braun from Netgear in Lockport, Ill. “They were able to provide me with a new Warp-9 motor that is really popular with hobbyists who build electric cars. The motor had been run only once on their test equipment, and because we were doing this project they offered a good price,” he said.

Initially, Braun had envisioned powering the tractor like a go-cart, with low 48-volt electricity, but after doing the math and other research he had to admit that the 48-volt system just wasn’t going to provide sufficient power. “Then I thought about moving up to 72 volts because the higher the voltage, the more efficient it runs, and the less heat it generates. I have a lot of horsepower needs, and need that power for a long duration,” he said.

Ultimately, the decision was made to go with 12, 12-volt batteries, totaling 144 volts, which is very powerful. “Interstate worked with me, providing a very nice discount on their high-grade batteries for agricultural operations,” Braun said.

He emphasized that the rate the battery can give off its energy into the motor is more important than the charge rate. “That’s important because a tractor is operated at close to the same horsepower continuously,” said Braun.

“A lithium ion battery in an electric car would be about 4 to 6 times more expensive than these batteries, but while that’s a better technology it wouldn’t serve me any better because I don’t need the rapid recharge,” he said.

The batteries, which weigh 70 pounds each, combined with the electric motor and mounting brackets add about 1,000 pounds to the tractor. “That extra weight on the tractor provides better traction. Besides, when it was fully weighted from the factory that M would actually weigh more than it will with all of the batteries. More weight in the tractor world is a positive, while weight in the car world is a big negative,” Braun said.

“Because we’ll be operating at 5-7 miles per hour, and not concerned about running at 70 mph, there was a lot of time spent figuring out how to get the power into the tractor, which was one of the biggest challenges we faced,” Braun said.

“Going through the PTO wasn’t really an option because you’d lose use of the PTO, and besides, it’s used to drive implements, not for driving the tractor,” he said. He saw the potential to utilize older tractors from the 1930s through the early ‘60s, that have a belt pulley.

His thought was to transfer power into the pulley housing because it’s located behind the engine and the clutch. “It’s a direct drive into the gearbox transmission itself and it’s also intended to take that high horsepower, which is rated under 50-horse,” Braun said.

Switching from gasoline power to electric would require depressing the clutch. “We’ll have a clutch interlock, so the engine would be off then and the clutch simply will be down. It’s pretty simple other than the wear on the springs which is a pretty minor sacrifice,” Braun said.

Joe Keim, who owns and operates Joe’s Fab Shop near Marion, designed and fabricated the equipment that houses six batteries on each side of the tractor, and electric motor that’s located adjacent to the pulley housing and operates the pulley through a set of belts, providing power to drive the tractor like an electric car.

For added safety, the decision was made to connect the motor and pulley with a double belt and tensioner instead of a chain. “We rated the belt at 55 horsepower with the tensioner and belt design, so if the electric motor were to exceed that level, the belt would simply slip. We didn’t know at what level a chain could break,” Keim said.

Mechanical Drive Solutions supplied and machined the pulley, which has a keyway that compresses where it clamps against the pulley. The outer part of the pulley is the sprocket with teeth.

Another challenge was protecting the high voltage batteries and cables. “So Joe installed nylon insulating material inside the battery covers to prevent fire if the batteries were damaged. Each battery case also had two padlocks to keep unauthorized people from accessing the batteries.”

Phase 1 involves proving the project concept works, according to Braun. “I’m hoping to have it tested by fall, he said. “Phase 2 is the engineering portion when we’ll evaluate the practicality of the concept.”

The experiment year will begin in the spring of 2024. “As soon as I see green coming out of the ground, and tractor work starts, I’ll start Phase 2 of the project,” he said.

Meanwhile, Braun is providing a variety of ongoing outreach activities to the local farming community, including video data and print reporting on the conversion process and project results that may be used for outreach and future tutorials.

Wisconsin State Farmer will continue to follow the progress of Braun’s project with additional articles. You can learn more about Pigeon River Farm at pigeonriverfarm.com and view project videos at https://bit.ly/3DuNL7D