Have tried using the strongest cuboard magnet I can find (In north
London u.k.), but if the wind picks up surprisingly it will just not
hold. Also

The magnet out of a hard drive is flat and very strong.

Really? What kind of hard drive has a big flat magnet inside? That defies
all logic on the principals of how a hard drive works.

Contra-intuitive, but true nonetheless.

A hard-drive has a pair of the most vicious magnets you are likely to
encounter outside of a hospital's MRI dept.

They form a simple head position actuator.

--
Graham.

%Profound_observation%