It's ugly.

It doesn't seem to have much effective dihedral. For a rudder/elevator only plane, that could be problematic.

Kind of pricey, but I think that thing is pretty dang cool!

http://www.asl.ethz.ch/research/asl/...lar_Flight.pdf

Also Google Dave Beck Solar Solitude. He set records for solar powered flight back around 1996 here in Wisconsin and is a member of the Valley Aero Modelers in Appleton which I have been a member on and off over the years.

This is far from the worlds first. Either for solar powered flight or commercially available. I guess that having the Internet filtered in China does not allow them to research statements before they make them

Did the Graupner one actually work? Was it able to provide enough power to sustain flight on the solar alone? Just curious really. That is the only commercial product I could find, but its so old that I doubted it could have possibly worked. Everything else has been custom built.

I've adjusted the title to avoid further confusion.

Originally Posted by Jason Cole

Did the Graupner one actually work? Was it able to provide enough power to sustain flight on the solar alone? Just curious really. That is the only commercial product I could find, but its so old that I doubted it could have possibly worked. Everything else has been custom built.

I've adjusted the title to avoid further confusion.

The Graupner is claimed to have "unlimited flight on sunny days". I consider Graupner a very serious company that would not make such a statement of it wasn't possible...

Originally Posted by mike_o

The Graupner is claimed to have "unlimited flight on sunny days". I consider Graupner a very serious company that would not make such a statement of it wasn't possible...

That's great if you live in Arizona, but in my neck of the woods, where its overcast 50% of the time, you'd have to rely on plain old fashioned batteries.

By the way, isn't Graupner a very serious company that went bankrupt?

Originally Posted by WimH

1991 or thereabout

Actually I owned this same pictured Solar Uhu build by Kurt Maier(RIP) for Graupner ~ 23-24 years ago.

Model latest until I thaught good trainer for my wife and handed the trainy over

Originally Posted by wakumann

Model latest until I thaught good trainer for my wife and handed the trainy over

Allow me to translate:
"Model lasted until I thought [it might be a] good trainer for my wife and handed over the tranny"

: )

See you in April, Thomas, for English 201 at Tri Cities... : ) : ) : )

There were even earlier solar-powered models scratch-built by dedicated pioneers. One of them was Oskar "Ossi" Czepa who in 1992 (23 years ago) built the solar-powered Solitair: www.czepa.at/solit.html

Dieter Mahlein, ShredAir

Here is one of the pioneers of Solar gliders; they should have contacted him if they want to really build a true solar power glider. I believe, if my memory serves me right; this glider was flown for 24+ hours with FPV gear too.

Originally Posted by rockyabq

It doesn't seem to have much effective dihedral. For a rudder/elevator only plane, that could be problematic.

I noticed this as well. I can't believe that the nuts that designed this would miss that detail? Maybe the picture is missing a dihedral joiner for the center panel?

Also, if the prop folds, how do you use it as a generator while braking? Doesn't there have to be centrifugal force to keep the blades spread? Or am I missing something?

R,
Target

...solar constant is equal to approximately 1,368 W/m2 (http://en.wikipedia.org/wiki/Sun#Sunlight)

...times 20% (http://en.wikipedia.org/wiki/Monocry...con#Efficiency)

..equals 273.6 W/m2 out of the cells

...optimistically guessing the wing area is 2.85m * 0.2m = 0.57 m2

...we get an ideal* power output of 0.57m2 * 273.6 W/m2 = 156 W

*ideal: it's a nice day, and most importantly, the sunbeam incidence is exactly perpendicular.

My conclusion is that the claim of indefinite flight time (in good sunlight anyway) is perfectly conceivable. Even if we get only 30% (45 W or so) of that best-case output to the prop, I'd reckon a properly designed sailplane could maintain altitude. Does this one do? No idea, but I see no obvious reason it couldn't.

Hey, I fly a Solius, but it is a proven semi scale ASW made by Multiplex....
Boo on ripping off the name...

Chief

I spotted the lack of dihedral too when 'Drone Industries' (whoever they are) first posted the photos over in the electric plane forum.

The other 'curious' design feature is tail surfaces that appear to be thick 'slab' flat plates with no airfoil, plus servos hanging out in the breeze and their wires routed externally up the fin. Minor details maybe but they don't exactly scream 'high performance' or 'quality'.

Possibly this is just a proof of concept prototype but more details are not forthcoming as yet.

Wondering how regenerative braking would work with a folding prop...
Also, all simulations I run tell me for this plane size, weight, motor, voltage, the most optimal prop would be 18x12, there is no reason to use a 24" without a gearbox.
There is no a benefit to have the biggest prop you can buy...