Making a DC Motor

A rough sketch of a DC Motor.

Having students construct a simple DC motor is a great way to learn about the interactions between electric & magnetic fields.

Materials needed:

• Pine from your local hardware store
• Wooden skewers 
• Horseshoe magnet
• Split pins
• Enamelled copper wire 0.5mm
• Copper foil (I used 0.1mm thickness but recommend probably around 0.3mm)
• Balsa wood for shaping an armature (or a 3D printer to print an armature as we did in this example)
• Masking tape
• Razor blades

Note:
The Armature is easily made by shaping some 25 x 25 mm balsa with a razor blade. Getting a nice balanced armature can be tricky and requires some patience. If you have access to a 3D printer you can have students design an armature using Google Sketchup. Once printed, it can be placed on the shaft and copper can be wound around the armature.

Also note that the copper wire must be enamelled. The enamel then should be sanded only where the brushes make contact. The enamel works like insulation in the coil and allows a force to be generated.

End Result:

Next Step:

To create a split ring commutator with adhesive copper tape so that our motor looks a little more like an actual motor. ie.