That analysis might be a bit harsh.
The lifting kite we used had a couple of thin flexible spars in it ...
rigidity
The steering for the lifter is a metal frame, radio, servo..rigidity
The top hub used was from a mountain bike and was too big for what was
needed... rigidity
All of the rigid matter up top lifted fine.
The problem with our last test was that the stem was too flexible to
hold the weight of the bottom hub (The hub bellow the ring set) and the
brake and the cuff and the tethering wheel...
It was all on a long flexible pipe.
This had the unfortunate side effect of drastically misaligning the
tethering ring and the kite ring.
In the rare seconds that they aligned, it looked good... really rare.
The first ring prototype never had that problem as there was no
alignment issue, all the tethering ran from 1 point.
If that extended ring set idea or even just one lifted ring idea is to
be lifted , then the bottom hub should be balanced in a gimbal to allow
the tension from the kite ring to align it...
Furthermore, the first (lowest ring or only ring) should be set as a box
ring kite (one ring sparred to a front tethering ring)
The lifted hub (yes it is weight up high) is not a heavy weight, It does
have to cope with the line tension, that will be a maximum when all the
rings stall and collapse... otherwise if the rings are flying the line
tension is reduced due to ring kites lift.
I am opposed to weight up high as well. But it is a simple elegant
method.
If we want to control kixels by line, we will need rigid smooth rings
mounted on our loadpaths to run control lines. OK they're tiny too but
still rigid.
This whole parametric algorithm design course I'm putting myself through
is mincing my head though...
I am definitely going to end up drawing meshes of organic loadpath
arches with triggered twitchy gill sails
Another good laddermill idea you'll not approve of Dave S.... may use 2
hubs lifted up to opposite sides inside an arch. a continuous rope with
the outermost edge of many kites runs through the hubs (wheel sets), the
inner edges of the kites are banded on a short band and the tethering
for the kite ring is collected to a central tether (spinning or
swivelled) Power is taken from the band at the arch feet as the band
runs through ground wheels.
--- In
AirborneWindEnergy@yahoogroups.com, dave santos <santos137@...
wrote:
dead-end. Even at your modest experimental scale, your experiments gave
you a nice clear indication that larger torsion hubs can hardly fly up
high into better wind. That's a great result, since it confirms a design
path to avoid. Instead, you chose that architecture for a Kite Power
Coop logo :)�
lessons that can steer us toward real solutions. The more
failure-lessons one can bear, the greater the eventual success. Too many
folks in AWE sink with their ships, rather than jump onto a better
one.�At best, only a large surface hub (that does not fly) is
megascalable (carousels and ring tracks).
