Physics Lab Project: Design and Build an Electric DC Motor

[Rastabot]

Homework Statement

Hey, For one of our final lab projects, we have to (less design and more build) an electric DC motor on a 6V DC battery.

Restrictions/Requirements:
No plastic parts can be used
The motor must run for at least 60 seconds
No simple motors allowed
"not-simple" means, it must have brushes and a commutator.

Homework Equations

The Attempt at a Solution

I know the physics behind it, but I'm having trouble building it. What would be good material for the armature? And do I wrap the coil around the armature and then wrap it around the axle?
Any tips or resources on this would be helpful, thanks in advance.

 

[TVP45]

This isn't exactly what you need (and you need to figure this out for yourself anyway), but it shows a lot of simple construction techniques that should get you started.
Good luck.
http://sci-toys.com/scitoys/scitoys/electro/electro2.html#bigger