# What do you think about "e-soaring"?

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#### John.Roo

Those gliders being on-line auctioned by the RAAF in Oz , are now around $40k 40K is still OK - lets see final price #### ypsilon ##### Well-Known Member For$
Those gliders being on-line auctioned by the RAAF in Oz , are now around $40k For$40K each, I would buy all of them.

#### EzyBuildWing

##### Well-Known Member
Embraer to build glider-like 9-seater all electric........contra-rotating props....... looks nicely styled......

#### John.Roo

##### Well-Known Member
Nice advertising for Akaflieg Karlsruhe school.

And seems that they like flying wings

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#### John.Roo

##### Well-Known Member
Embraer to build glider-like 9-seater all electric........contra-rotating props....... looks nicely styled......

I like this design....

#### John.Roo

##### Well-Known Member
1:2 scale model of AK-X spin test.

360°video version....

Really good job of the students

#### John.Roo

##### Well-Known Member
... and AK-X scale model wing production...

#### EzyBuildWing

##### Well-Known Member
A little off topic, but this flying display by a glider has to be one of the most beautiful that I've ever seen......

#### John.Roo

##### Well-Known Member
A little off topic, but this flying display by a glider has to be one of the most beautiful that I've ever seen......

I agree, Jaroslav Potmesil makes beautifull gliders
Definitelly not "off topic" in this thread

#### danmoser

##### Well-Known Member
From my point of view is Mr. Geiger system designed more for amateur builders. MGM is focused more on professional users and solutions designed for specific projects (like propulsion for GP gliders etc.).

Geiger systems are like LEGO
You can buy only 2 battery packs and later connect more (up to 8 if i remember well).
Is designed like "plug and play" so you decide what power do you need and systems comes with wiring and all parts you need.
Positive is that Geiger battery pack size is unified. However this can be a problem if you need special shape of batery pack (we had that problem because we have battery cells in wings and fuselage).

"25 hp Moni motorglider"
View attachment 117732
Nice

First of all - how much weight you have available for propulsion system installation?
(MTOM - EW - pilot weight - actual engine installation weight)
And... what is power you need for horizontal flight?

I had problems with motor temperature - max. power was 60 kW, but max. cont. power was 30 kW. Not a problem for flying, however is really good to pay attention to cooling system.
Battery capacity is important to precede problems with battery overheating.
With controllers I had no problems.

Honestly....
Solution based on ZERO is not that bad because of price and whole system package (motor, battery pack, controller, charger).
However I agree that shoudl be not from "wrecked" motorcycle.

Best regards!
Martin
Thank you very much for your input, Martin.
I'll be in touch with Geiger soon.

My own version of the Moni with extended span will need only about 7 hp (5 kW) shaft power for economy cruise level flight, depending on which prop is selected.
For reasonable climb rate plus margin, 25 kW peak/15 kW continuous would probably be about right.
Firewall forward mass allocated for batteries, controller, motor, and prop is approximately 80 pounds to get the CG right.
More battery mass can be accommodated by locating some of the pack further aft ( inside the cockpit) though I'd prefer to keep it all forward of the firewall.

I do like the electric setup on the Aerolite 103 .. it seems perfect for that aircraft, though it does seem a bit on the heavy and draggy side for a motorglider.

#### John.Roo

##### Well-Known Member
Thank you very much for your input, Martin.
I'll be in touch with Geiger soon.

My own version of the Moni with extended span will need only about 7 hp (5 kW) shaft power for economy cruise level flight, depending on which prop is selected.
For reasonable climb rate plus margin, 25 kW peak/15 kW continuous would probably be about right.
Firewall forward mass allocated for batteries, controller, motor, and prop is approximately 80 pounds to get the CG right.
More battery mass can be accommodated by locating some of the pack further aft ( inside the cockpit) though I'd prefer to keep it all forward of the firewall.

I do like the electric setup on the Aerolite 103 .. it seems perfect for that aircraft, though it does seem a bit on the heavy and draggy side for a motorglider.
You are working with nearly same numbers as numbers of propulsion installed in Sagitta
(and same was used in Song)
I also fly horizont with +-5 kW. Only max. power is bit lower - 20 kW.
Battery 14S (50.4 V nominal) - 6 kWh / 30 kg in 2x 15 kg pack.
Due to motor installed on pylon is no problem with overheating.

In case of Mr. Geiger system I would definitelly recommend you to ask for 2 battery packs (also 2 x 15 kg).
Please think about prop diameter you would like to use (= RPM).
M. Geiger motors parameters:
HPD16 = 16 kW cont. / 20 kW max (weight 4,7 kg), max. RPM 2 280.
HPD20SD = 20 kW cont. / 25 kW max (weight 4,7 kg), max. RPM 2 600.

Honestly....
Main reason why I mentionned Aerolite 103 electric propulsion system is... price.
Second reason is transport - Aerolite is based in US so no problem with transport. However Mr. Geiger battery packs are designed for safe transport so this should be not a problem. Anyway ask for expected transport price - whole package will have over 40 kg.
Third reason... US standards (110 V etc.)

Would be great if you can share with us your experience

#### EzyBuildWing

##### Well-Known Member
Foiling = soaring..????
Well, sort of.....!
Neat vid here.........

#### EzyBuildWing

##### Well-Known Member
Glider Auction....about 5 of these motorized 2-seat Schleicher Gliders (built 2014) are being auctioned on-line in Oz......about 1 day to go until the auction closes....
The Gliders are ex RAAF.
Latest auction price reached right now is about A$42,000 Might be of interest. #### raumzeit ##### Member Speaking of gliders for sale, on a popular hang gliding site here -> The Oz Report hang gliding news - FreeClassifieds there's an ATOS VRx for sale. Its a VX-sized sixteen meter wing but setup like a VR! A lot of talk on this thread about stuff like EGO trikes and Silent Gliders etc. For such applications that VRx wing is essentially the unicorn I'd think. #### OhAnElBirds ##### Active Member I like both kinds... E-107 soaring and E-113 soaring. #### EzyBuildWing ##### Well-Known Member OK.......those 2-seat Schleicher Gliders built 2014 mentioned earlier were eventually auctioned off for around A$130,000...........which is about US\$100,000
Might be of interest.

#### henryk

##### Well-Known Member
“Pseudo-Ornithopter Propulsion” by Grant Smith.
=I dont see ellastic elements (f.e. rubber springs...) ?

-I was investigated dr Wolf hang glider like harnees=simple and effort less movemant=
=amplitude of pilot oscillatings circa 0.5 m, long time "work" possibility !

#### jedi

##### Well-Known Member
You are right. My proposal did not include springs. A spring makes the effort less effective. Work is expended compressing the spring and then again controlling the expansion. The air acts as a spring to return the glider to the wings up position. In my opinion and experiments the "air spring" is very strong.

What is really needed is a negative spring. Instead of converting movement into potential energy in the spring the spring responds to the pilots input by giving up potential energy and assisting the pilot input. When the pilot pushes the spring also pushes assisting the pilot. Then an external power supply, battery or motor, replaces the potential energy for the next power stroke.

The aerodynamics that produce the thrust provides heavy damping to any oscillating spring mass system. It is not like jumping on a trampoline. It is more like jumping in quicksand.