How to Find Cheap Electric Motor For EV Conversionby Richard Rowe
Electric vehicle enthusiasts are an odd sort of subspecies in the "gear head" universe. One part Theodore Roosevelt, three parts Nikola Tesla and at least half-part Genghis Khan, EV builders are nothing, if not a prime example of intellect run amok. But that plays well for the EV builder, who shares a certain kind of opportunistic creativity and perceptiveness with his auto mechanic brethren. It almost seems as though half of becoming an electric Victor Frankenstein is about knowing which graveyard to pillage and how much to pay for admission.
Change your game plan to use a manual transmission. While some EV proponents will tell you that electric motors don't need transmissions, the fact is that using a transmission can save you some big bucks where the motor and weight are concerned. Going with direct drive means that you'll need to use a massive, low-revving motor to provide adequate torque for start-up. Using a transmission with a 4-to-1 first gear ratio means that you'll need to use a motor that spins four times as fast, but which is also likely 1/4th the size, weight and cost of one sufficient for direct drive use.
Look for used forklifts. Electric forklift drivetrains are pretty much the Holy Grail for EV car builders. Forklifts use two different kinds of motors; the lift motor, which operates the forks, and the main traction motor. A forklift is practically an EV conversion in a box, with all of the motors, motor controller and battery provisions that you'll need. And they can be pretty cheap if you shop around; between $500 and $1,000 isn't out of the question. Be wary of buying online. The forklift itself may be cheap, but you're still going to have to pay to ship it.
Use multiple motors. It is hard to find a decent, working 200-horsepower electric motor for less than the cost of a small house. If you want to do more than just putter along, then you might consider running multiple smaller motors. Smaller and less powerful motors are easier to come by, and that makes them cheaper. There's no law saying that you can't connect several small motors onto a common hub using a chain drive, or that you can't connect them lined up in series through a common shaft. Use your imagination.
Convert a generator to run as a motor. A generator is essentially just a motor running in reverse, so conversion is a very real option if you have knowledge and materials. Converting an alternating current generator to run as a direct current motor involves replacing the generator's rectifier with a powerful inverter and adding a Hall effect sensor to trigger the field. It's a lot of work, but it may pay off if you happen to score a 40,000-watt generator, or a few 10,000-watt generators for next to nothing. Keep on eye out; scrap yards are a good source for old industrial generators, provided the generators haven't already been stripped for their copper windings.
- "Build Your Own Electric Vehicle"; Seth Leitman; 2008
- "The Electric Car: Development and Future of Battery, Hybrid and Fuel-Cell Cars"; 2001
- "Foundations of Electrical Engineering, Second Edition"; John R. Cogdell; 1995