This is a simple top I thought of while I was creating toy to teach inertia.
Step 1: Materials
It just needs
An old but working DC motor from any old toy
Step 2: Test the Motor
Just check beforehand if the motor is working and the battery can be connected properly and removed as and when required.
Now is the toughest part. Actually it is not tough if you get the hang of it. Connect the motor to the power supply and juice it up to a proper speed. As the top speed is reached, in one swift go release the motor and remove the power supply.
Check the video how to use the top.