The crank up/down idea is good, though you couldn't have guy wires, It would
be relatively simple to do with triangle style open tower. The trolley for
the blade assembly would be pretty straightforard - six cupped-out
wheels/pulleys in a hinged or bolt together configuration with 3 wheels
above the hub and 3 below. (I say hinged or bolt together because how stupid
would it be to have to go to the top of the tower to drop the trolley over
the top of it) - A big steel cable would then go up through the middle and
over the top to the trolley and voila. Hook it either to a hand crank winch
like on a boat trailer or some other kind of braking electric winch, and
there it is. Electrical cable would obviously have to run up the outside of
the structure, but you could simply run a single thin piece of steel cable
along one of the triangle flats with a series of rings fixed to the electric
cable that also slide up and down the stationary steel cable. This would
keep them from blowing around, and allow the electrical cable to neatly pile
on the ground with you bring it down for maintenance. OOOOOOR...
Some of the armature radio guys have these giant telescoping antennas that
they can crank up and down... Obviously none of them are built to take a
physical side to side load like a turbine would put on them, but its a good
place to start...
http://www.alumatower.com/new/telescoping.html
Maybe I'll do something up in solidworks..
Andy