Motor help? I build this simple DC motor for a physics class using 24 gauge magn

Question

Motor help? I build this simple DC motor for a physics class using 24 gauge magnetic wire and household materials. It runs perfectly even when hooked up to a 3V battery, but for the assignment it must lift a 20g mass up 1 meter. I've tried tying the string that holds the mass to every possible location along the dowel rod and the armature, but as soon as I secure the string, the motor turns for a second and then stops, or else doesn't move at all. How do I get the motor to lift the mass? I've read that I should increase the torque and therefore decrease the speed; how would I go about doing that? I've tried higher voltage batteries to no avail. Suggestions please? Thank you.

Explanation / Answer

The only possible way to lift up the mass without changing the core design is to reduce the torque on the motor produced by the mass. If you tie the mass to the axle, the torque is too much for the armature to pull, as the axle is thick.

So here is one possible solution, take a long but thin nail (maybe 2"), now drive a small portion of the nail along the axial line into one end of the dowel rod in such a way that the nail and the dowel rod will have the same rotational axis.. Now tie the string to the nail and make sure it doesn't slip, you can use superglue to fix the string permanently. Use a thin cotton string to make the lifting part as light as possible. Remember the nail has to be thin.

Apart from this particular problem I can see that your dowel rod is not completely straight, I think that had some of the impact on the stability of the system.

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