The basic components of a dc motor is shown below
Electricity from the motor terminals comes down the brushes and are transferred to the commutator which is connected to the armature. The armature is a coil of wire which creates a electromagnetic force which propels off the magnetic force of the magnet and turns the motor shaft.
The reason for running motors in is to bed in the brushes against the commutator so get best electrical connection and therefore transfer as much electrical energy to the armature to improve efficiency.
So this is the process I used to bed in my motors. The motors are rated at 7.2v but since we want to take it steady I used a 3v power source.
As I had two motors I connected them in parallel.
Now to make sure each motor gets same energy I connected the positive supply to one motor and the negative supply to the other
I then left them running for eight hours. Then switched supply polarity and ran for a further two hours in reverse.
An alternative method if you don't have a 3v power source is using a regular 7.2v battery pack.
First up, is connect the motors in series. i.e. battery positive to motor +, motor – to second motor +, motor – back to battery negative.
This method spreads the battery voltage across the motors so 3.6v per motor.
