Electric vehicles are extremely popular nowadays, and finding new ways to power them is a large goal for many manufacturers and makers. YouTuber Emiel, The Practical Engineer recently designed and built his own solenoid engine, but his audience wanted him to go one step further: integrating it into a car.
Both solenoids and electric motors work on a similar principle. A tightly wound coil of wire goes around some kind of housing and an electric current is applied. Within that housing sits a magnetic rotor with two sides that each have an opposite polarity.
The difference here is what happens to that rotor. In a motor, the magnetic field causes the shaft to rapidly spin, whereas the shaft simple moves either forwards or backwards in a solenoid. Although they don't produce much force on its own, a solenoid can still move quite rapidly and mimic what a piston does in a conventional internal combustion engine.
The engine was designed to look like a classic V4 with two rows of opposing cylinders on either side of the central axis. Just below them sit four linkages that connect the solenoid shafts to the crankshaft which makes a full rotation for every complete cycle.
Due to this not being an actual engine, there's no gas, oil, or spark plugs to worry about. Instead, the timing is precisely controlled by checking the current position of the crankshaft with a set of four IR emitter/receiver pairs that tell the Arduino Nano which solenoid needs to be activated next. Otherwise, as can be seen in the video, the solenoid timing will get out of sync and cause the mechanism to lock up.
The frames for both the engine and the car were created out of several pieces of aluminum, with a pair of large, central pieces being used as a the chassis. Otherwise, the rest of the car was fabricated from 3D printed parts that comprised both the front, rear, and body. Power is transferred from the engine's crankshaft via a timing belt, which is wrapped around a rear pulley and axle combination that drives the back wheels. And even though there is a lack of steering onboard, adding extra weight could impact the speed even further.
In his experiments the car performs well enough. It can drive at reasonable speeds while also making that classic engine "knocking" sound from the solenoids activating. However, there's a very noticeable lack of torque on the wheels which could be alleviated by spinning the crankshaft faster, although this would greatly increase the likelihood of an engine failure. So for now the electric motor still reigns supreme for vehicular transportation.