Montana Tech students to present plan to convert diesel-powered vehicle to electric at Techxpo

At Montana Technological University’s Techxpo Design Showcase on April 24, 2025, a team of seven students will present their design to convert a diesel-powered Mahindra Roxor to an electric power system that can be utilized by the Underground Mine Education Center.

This project is one of more than 86 entries by 165 students at Techxpo, a campus-wide event aimed at showcasing the hard work, innovation, and excellence of students. Exhibits will include projects in science, engineering, and mathematics. A panel of industry professionals judge the students’ projects, and the top project in each category is awarded a cash prize.

The event is free and open to the community, as well as industry partners, alumni, and local area high school and middle school students. Opening remarks begin at 1:30 pm, followed by judging and an awards reception at 4:30 pm. For more information, visit https://www.mtech.edu/techxpo/.

The team presenting the vehicle conversion project includes electrical engineering students Dorian Obergfell, Collin Badger and Benjamin Rohrschieb, as well as mechanical engineering students Zoee McGowan, Aaron Kelly, John Cashell, and Justin McKnight.

In some ways, this project began two years ago, when Obergfell, from Sidney, Montana, was a sophomore and asked his advisor, Electrical Engineering Department Head Dr. Bryce Hill, if he could spend a summer learning more about Tesla electric motors. Hill agreed, and Obergfell was able to experiment with a 2018 Tesla Model S motor as part of a Summer Undergraduate Research Fellowship project.

By the time senior design class got underway, a 2021 Mahindra Roxor had been donated for students to experiment on as well. The group was challenged to convert the vehicle from diesel to electric power for use in the Underground Mine Education Center. The students had to write a paper analyzing why the conversion we did the cost analysis of getting the fuel to the mine site.

“Gasoline and diesel fuel are cheaper, but the whole process in itself, including getting that fuel to the mine, filling it up, that sort of stuff is more expensive than just having power lines that are already there. You don't have to pay a worker to come drive it and fill it up for 15 minutes,” Obergfell said. “With electric, you have a one-time charger cost, and plugging in takes just three seconds.”

There’s also concerns about emissions being released into the confined space where people are working.

“In a mine especially, this is important, because they have to be careful how long they run the vehicle in the mine,” Obergfell said. “You're in a closed space and you don’t want to have carbon monoxide, anything like that coming out of the vehicle.”

Planning for the conversion was a huge project. The electrical team had to overcome barriers inherent with working with Tesla motors.

“The biggest challenge with a Tesla motor is that Tesla has proprietary software that runs their motor,” Obergfell said. “Most of the motor is run from a computer. When you buy a Tesla motor, you can't just interact with Tesla software because it's illegal. You can't even access it without a special code that they change once a week or whatever it is. Our challenge was trying to figure out how we're going to interact with this motor, set the parameters for the vehicle that it's going in to run correctly, and get the torque outputs that we need, the power outputs, especially with a smaller voltage than what a Tesla motor usually runs on.”

The electrical team found a solution through the help of Damien Maguire, an Irish electronics engineering who builds logic boards for Tesla motors.

“Basically, you take out Tesla's original logic board, and you put in a new one,” Obergfell said. “What this does is it makes it so that the motor is run off of the parameters that you set for it. It connects to a Wi-Fi signal on the computer, and you can set the parameters for the motor.”

The mechanical team also had to overcome several hurdles, according to McGowan, a student from Missoula.

“Usually for a normal conversion like this, the engineers put the small Tesla motor inside of the engine bay where the old engine used to be at, but our idea is to put it right after the transfer case,” McGowan said. “The reason why we're doing this is because if we put the electric motor in the engine bay, then we would have to make changes to our suspension and our brakes and our steering. We have to figure out where to put the batteries as well. We are going to put those inside the engine bay instead.”

McGowan notes that while it may seem like simple conversion it’s not. Engines powered with fossil fuels also power many other parts of the vehicle.

“A bunch of things run off the engine,” McGowan said. “The engine is the part that drives the vehicle to move, but your power steering pump is attached to your engine, and that gives your power steering pump power to be able to not have to crank your wheel 20,000 times to get it to turn left or right. You’re also getting power from your engine to operate your alternator, water pump, and a bunch of different things.”

By contrast, electrical engines are much more sophisticated.

“Tesla has a separate system called a Communication Area Network (CAN), and it's a completely separate system from the way that the motor runs. There are also things on that CAN system, if they go wrong, then the motor won't even start.”

The electrical and mechanical engineering students think they’ve found a way to meld the vastly different operating systems into a functional converted vehicle, though it may take a little while to put the ideas to the true test.

This year’s seniors spent a year working on the project, and another group will take over next year to get the vehicle functional and into service for the UMEC.

The project is being completed under supervision of Montana Tech instructors Dr. Richard LaDouceur, Dr. Kevin Negus, Dr. Brahmananda Pramanik, and Dr. Bryce Hill.