S O L E N O I D E N G I N E HOMEMADE

At a solenoid engine the driving force is the electromagnetism.
A solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field. With a special shape of a washer to the one end of the axis and a counterweight to the other, the power supply to the coil cuts the current using
a limit switch for a half of every round and gives the current again to the other half. So the engine works continiously as long as it is connected to the power supply.
We need a coil with 750 rounds ( 0.5 mm) and a voltage 10 V or more.When we increase the voltage the engine works faster.
You can see the construction here: https://youtu.be/FtZF4DCD3r4