This actually fully relates to the MMG motor.
Guess where the magnets came from for the rotor !!!

There are normally 2 thicknesses of these 'bowel' magnets in HDD's and 2 of them per drive. One type is much thicker than the other.
I used a thin type for the rotor. The magnet is released from its metal housing with a sharp tap of a flatblade screwdriver and hammer. Then, placed between pliers, crushed to the right dimensions of magnet size needed ( x4 for a 4 magnet rotor).
Weirdly, for magnets, they can take that bang with the hammer and then the crushing with pliers with no magnetic detriment.
They don't like sticking to a soldering iron though, lol, releasing their magnetic equivalent of magic smoke in under a minute.
I have a couple of drives left that were intended to be spares, but are only 4.3Gb and such. Will set about dismembering them and try this spinning malarky out.
It should be 100% a case of the string unwinding.
Also, in one of Ed's videos, he has a white ball with his name and the date, spinning above a Levitron 'World stage'. It seems to spin fast and then slow within each revolution as it goes....has to be from a mechanical input to result in a faster spin after 12 minutes ? (waving a hand left and right, or from above, with a magnet held in it).
if not, we need to find a semi-levitated way of testing without string.
Btw, this made me smile, because of the weird anti-clockwise spin that a rotor seemed to do on its own a while ago. It's one of my Bench posts. Seemed to spin when I had my hand above it holding a magnet as still as could be and should, 100% be involuntary muscle movements. But, it would rotate at the same speed and in the same direction each time tried.
This one:
http://www.overunityresearch.com/index.php?topic=2758.0