In class we also had a bit of a brainwave in how we can achieve the feeling of magnetic levitation. We decided suspend the fan on cotton thread from a base with the magnet in it and a magnet on top. By doing this it becomes possible to attach the cord to a motor that can control the fans rotation and simulate the spinning up and down of the fan according to the number of 'flames' (now LEDs for the proof of concept). Here was the working we used for the height that we needed the prototype's frame to be:
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| Stated here are the height requirements of the elements to fit below the frame. |
This video demonstrates how the fan is levitated/suspended between the cord and the magnet above. You don't have to look too closely to notice the cord however it provides the feeling of levitation that we need for the proof of concept model.
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| Proof of concept prototype ready to be tested with the heat from the candle flames. |
As shown in the videos below I initially tested the concept with the candle flames and one of two issues consistently occured:
The cotton thread supporting the fan broke due to a combination of the heat and strain.
The cotton thread supporting the fan shortened too far due to the twisting pulling it too far from the magnetic field (this occurs at 3:48 in this video).
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| To account for the breakage of the cotton I tested fishing line with swivles top and bottom to allow it to spin freely however the friction was again too great to allow the fan to spin. |
In the end I reverted back to the cotton thread as it allowed the fan to spin more freely and to simulate the frictionless nature of magnetic levitation. This free spinning will however be replace with a motor attached to the fan using fishing line in the final model as this will prevent the wind up that occurs and causes major problems in the prototype.
I will look into how we can control the motor speed at low speeds tomorrow.
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