100% solar powerd solar-plane 'SunGlider4m' - RC Groups
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Oct 10, 2015, 10:59 AM
FPV IN THE SKY
Spuli's Avatar
Build Log

100% solar powerd solar-plane 'SunGlider4m'


SunGlider 4m

Hi!
I am from Austria (NOT Austraila) and flying FPV for quite a time now, and recently had the idea, to scratch build a highly efficient plane, capable of super long duration FPV flights and autonomous autopilot flight.
To accomplish this goal, the plane has to be capable of thermaling and of recharging its batteries while flying with the engines off.


So a few weeks ago I started on building the 'SunGlider4m' prototype!
Comments and suggestions are highly appreciated. ^-^

Therefore i designed the wings large and gave them an airfoil with high lift, what is also used for the Skywalker 1900.

Firstly I took the NACA 4412 airfoil from the Skywalker and scald it upo to a length of 50 cm. Then i made two wooden samples of it, sticked them on a 1 m long foam block and horwired 4 pices of it.
The wing is made of four sections.
The middle section is 1 m long and permanently attached to the fuselage. The left and right wings are 1.5 m each. The wingtips are made by cutting one of the four wing pices half and are attached in a 30 degree angle. The wing has no dihedral.
I hotwired hols for carbon fiber spars, which are 15 mm for the middle section and 10 mm for the outer sections. The spars of the outer wing sections can slide into those of the middle section and are held in by friction forces generated when the wing is under load.
In addition to that I will desing a snapping mehnism to make sure the wing does not fall appart mid flight. Plus I added rubber-like tape to the connection spars to get more friction.
The hinges for the ailerons are made out of yogurt cup plastic.
Solar cells will be mounted all over the wing.
The finished wing is 4 m long and 50 cm width.

---

To-do next:

I will build the tailplane next. It will be a T-Tail.
Combined with a twin engine setup, it should be max. efficient.
Last edited by Spuli; Oct 11, 2015 at 09:39 AM. Reason: spelling (I speak German)
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Oct 10, 2015, 12:58 PM
fly it high as possible
Quote:
Originally Posted by Spuli
SunGlider 4m
[B]Hi!
I am from Austria
The finished wing is 4 m long and 50 cm width.
---
Combined with a twin engine setup, it should be max. efficient.
Hi there,

What are you gonna use as a solar power?
Oct 10, 2015, 03:10 PM
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power and electronics setup


Quote:
Originally Posted by IL76MD
Hi there,

What are you gonna use as a solar power?
Hi,
thanks for asking!

I will use monocrystalline solar cells. Apparently the same, they used in the Solar Impulse project.
I have those on order:
http://de.aliexpress.com/item/150pcs...391693607.html
They are flexible, so the can be glued on the surface of the wing.
Some calculations:
On the surface of the wing I can fit 60 cells. This will generate 200 watts. If i put cells on the wingtips and the horizontal stabilizer, the plane will accommodate 90 cells, giving me slightly over 300 watts. This is more than enough to sustain flight.
I will be able to switch between battery and solar cells with a radio controlled switch.

power and electronics setup
You reminded me of telling my exact setup!
I run 2 turnigy aerodrives (https://www.hobbyking.com/hobbyking/...dProduct=40048), with 9x6 counter rotating props on 4s.
I use the multistar 4s 10000mAh LiPo.
My ESCs are Simonk 60a.
I use standard metal gear 9g servos.

Concerning FPV:
My OSD and autopilot is the arkbird OSD. (https://www.hobbyking.com/hobbyking/...dProduct=31162)
I use a redymaderc 1.2ghz 2500 watt tx and a pepperbox antenna on ground. My RC is dragonlink.

When the plane is ready to fly, I will test it on battery first. If it approves, I will fly it FPV, then I know dada like power consumption and handling in terminals. Contemplating this data, I will size the solar cells.
Oct 10, 2015, 03:18 PM
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deleted
Last edited by Spuli; Oct 11, 2015 at 05:31 AM.
Oct 10, 2015, 11:25 PM
Suspended Account
waiting for flight video
Oct 11, 2015, 07:15 AM
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wing joining


friction-and-screws wing joining mechanism

Today I built the wing joinings. I am very pleased with how it turned out.
I used hot glue to glue the wood the the foam.
Like you can see in the pictures, the wings slide together and then, they are fixed with two screws. It can easily be done on the field.
Those joinings keep the wings from falling apart under 'pulling forces' like someone pulls on the wingtips. The load from the lift is passed from the outer sections to the middle section through the carbon rods.
Like I mentioned earlier, the wings probably won't fall apart even without the joinings, because the lifting forces generate friction on the carbon rods, and so the will not be able to move.
But with my new joinings I can be certain that nothing bad happens to my wing in flight.
The wing now weights 1.6 kg and has a lifting aeria of 2.8mē.
Last edited by Spuli; Oct 13, 2015 at 04:24 PM.
Oct 11, 2015, 07:58 AM
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schumixmd's Avatar
For a 4m wing span, the ailerons are a little bit too small. It will not have enough autority while entering or exiting a thermal.
Last edited by schumixmd; Oct 11, 2015 at 09:31 AM. Reason: Grammar
Oct 11, 2015, 08:33 AM
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Quote:
Originally Posted by schumixmd
For a 4m wing span, the ailerons a little bit too small. It will not have enough autority while entering or exiting a thermal.
Thanks for your suggestion!
But they can move more than 45 degree up or down. Do you think That can help to compensate the size?
But I will definitely consider making them bigger.

Up to what angle do you think is an aileron efficient? If it is tilted 90 degree, it will only work as an airbrake, but will not create a force up or down.
Oct 11, 2015, 09:10 PM
ultra cheap pilot
ican3d's Avatar
I'm confused, is it safe to charge lipo while lipo is on use during flight? I'm very interested how the charging via solar panel on flight schematics works. Subscribed.
Oct 12, 2015, 12:42 AM
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Spuli's Avatar
Quote:
Originally Posted by ican3d
I'm confused, is it safe to charge lipo while lipo is on use during flight? I'm very interested how the charging via solar panel on flight schematics works. Subscribed.
Hi!
The problem is, at the time I do not have a solution for this myself. But I can switch between solar cells and battery with a radio controlled switch once my plane is completed. As I have estimated 300 watts of solar power, this will not be a problem to sustain flight. But I am still looking for solutions to charge in flight, to use all the power from the solar cells, even if I am flying with the engines off.
At least there must be a way, because cell phones to do laptos exactly the same when they are plugged into their charger.
Oct 12, 2015, 10:17 AM
Self employed
Efti's Avatar
Maybe this is something to use?
http://genasun.com/all-products/sola...ge-controller/

Or the other chargers
Oct 12, 2015, 01:52 PM
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Spuli's Avatar
Quote:
Originally Posted by Efti
Maybe this is something to use?
http://genasun.com/all-products/sola...ge-controller/

Or the other chargers
Nice idea!
The power might be a problem, since I have estimated 200 - 300 watts, and the charger can only handle 150 watts.

But some charger like this can be the solution to my problem!
Oct 12, 2015, 05:01 PM
The spinny thing points up!
Komitadjie's Avatar
Bear in mind that your cells will not be generating at full efficiency all the time! As you bank the aircraft, some or all of the cells will go into shadow, and if you are planning to thermal you will be doing a great deal of turning and banking indeed. Sun angle will also be of critical importance, a morning or evening flight will not generate the same amount of power as an afternoon one.

I'm looking forward to seeing how this goes!
Oct 13, 2015, 04:22 PM
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Spuli's Avatar

The fuselage


Hi!

I made progress!
I decided to build the fuselage before the tailplane, to be able to adjust the tailplane according to the fuselage.
This afternoon was dedicated to the build of the front part of the fuselage.

Fuselage

The fuselage is built out of XPS foam. It is a lot more rigid compared to the white foam I used to make the wings. The wings get their stability from the carbon fiber rods, so the foam is only responsible to form the airfoil. So I used this very light weight , but weak foam for the wings.
Since the fuselage will not be reinforced with carbon, it's foam has to be rigid, but XPS is way heavier than the white 'Styropor'. That is why I only use it for the fuselage and the tailplane.

Firstly, I took a piece of XPS and hotwired it to four pieces, each 1 m long. Then I hot glued them together. Next, I sticked the two wooden airfoil samples to the sides of my new 'fuselage' and howired it, to fit the middle wing section through.
Finally, I sticked the two wooden fuselage samples on each end of the still square fuselage.
After howiering it, it is nice and round.
tomorrow I will sand it, and build the rear part of the 1.6 m long fuselage.

On the front of the fuselage I will place an aerodynamic tip, when the plane is finished.
Sure, the fuselage will get a removable 'canopy' on the front to access equipment. Puls, I probably will build a removable cover on top of the wings-fuselage-joint.
That will provide a lot of accessibility for equilmet, while not affecting the rigidity of the plane, because all the forces from the wing are bypassing the wing fuselage joint through the carbon rods.
I do that last because of the center of gravity. Now I can place the battery 45 cm in front of the wings to adjust the center of gravity. If I don't need to place it that far in the front, I will shorten the fuselage.
Last edited by Spuli; Oct 13, 2015 at 04:30 PM.
Oct 15, 2015, 01:44 PM
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Fuselage part 2


Progress!
The rear part of the fuselage is now cut out!
Now, there are only the front tip and the rear cap missing to be cut out.
After that I will glue the fuselage together and reinforce the joint.
Then, the fuselage will be sanded properly, to eliminate little irregularities on the surface.
The fuselage now weights 600 gramms.


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