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Old May 16, 2005, 08:53 AM
Registered User
Aix en provence (France)
Joined Apr 2005
9 Posts
Antonov-124 building project

Hello All
I'm considering the building of a 1.50 m wingspan foam Antonov-124, but i'm not very confident in building such a plane.
I've already a very good plan of it that i found here http://www.airwar.ru/other/draw/an124.html
Some photos of it


And my problem is the choice of the motors.
I want to use 4 GWS EDF-64-300H like this one http://www.aircraft-world.com/prod_d...stem/edf64.htm
And a KAN 2 Ah 9.6V battery pack
I've already a 40A brushed controler, 4 Futaba S3003 servos, and a six channel receiver.
I don't know if those ducted fans will be enougth powerfull to move this plane.
I estimate the final weght around 2 Kg do you think that is under estimated.

I need some advices from the builders you are, thank you.

Sorry if i'am a bit confuse but i'm french and i dont speak english as well as i want.
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Last edited by lexma; May 16, 2005 at 04:28 PM.
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Old May 16, 2005, 09:29 AM
Registered User
Lyon (France)
Joined Apr 2004
258 Posts
GWS said that the EDF-64 give a 190g trust :

190g x 4 engines = 760g of static thrust for a 2kg plane it's possible but it will be under-powered.

In order to keep the plane as light as possible, I would use a Lipo battery (4000 mAh ?) and choose a light depron structure.
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Old May 16, 2005, 09:43 AM
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Aix en provence (France)
Joined Apr 2005
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in fact i dont know if 2 kg is a good estimation , because each edf weight 73g, with wires and controler the four motors will weight together approx. 350 g , another 350g for the 2 Ah Nimh batteries pack, 120g for the four servos.
350 +350 + 120 = 820 g only for furniture
Now the big problem is the weight of the foam, i dont really know how much it will weight with some balsa pieces for structure, i've estimated it around 1 Kg for
a plane that will be 1.40m long 1.50m wingspan and 0.16 m of fuselage diameter.
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Old May 16, 2005, 10:12 AM
Registered User
Lyon (France)
Joined Apr 2004
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Quote:
Originally Posted by lexma
120g for the four servos.
120 g for 4 servos ? For me 4 servos is about 40g.

For the structure, I think you can do lighter. I build a 2m Latécoère (a sea plane so water proof) and the structure weight is about 1kg.

Bye
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Old May 16, 2005, 02:13 PM
Registered User
Aix en provence (France)
Joined Apr 2005
9 Posts
I can use the EDF 75X4A model, it can provide up to 279g thrust with an intake ring, but what is an intake ring ?
But this ducted fan is a bit too large with a diameter of 8.6 cm whereas the motors are supposed to measure 6 cm ...
Can you give me others ideas\solutions, thanks

i put a link to this ducted fan
http://www.gws.com.tw/english/produc...stem/edf75.htm
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Old May 16, 2005, 02:31 PM
"Up Chuck-Up Chuck"
mdlifcrisis's Avatar
Ft. Lauderdale, Fl.
Joined Aug 2004
1,204 Posts
His servos are standard size. Some 9gr or so micros would be the ticket
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Old May 16, 2005, 02:38 PM
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United States, CA, Arcadia
Joined Nov 2003
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Sounds like a great project, keep us informed of progress.
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Old May 16, 2005, 03:24 PM
Registered User
Lyon (France)
Joined Apr 2004
258 Posts
[QUOTE=lexma] but what is an intake ring ?
QUOTE]


Sorry for the French :

Un "intake ring" est le conduit d'amission d'air. Dans ce cas il est en forme d'entonoir pour mieux alimenter la turbine (les Gws 55 et 65 en sont equipé d'origine).

If you want more power, you can use brushless engine, with the GWS 65 300g can be achieve. The problème will be the cost with a controler for each engine.

A solution is to build the plane for the gws 65 and to look at the weight for choosing the engine.

Bye
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Old May 16, 2005, 03:27 PM
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Aix en provence (France)
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Quote:
Originally Posted by foamflyer
Sounds like a great project, keep us informed of progress.
Thank you for your encouragements.
I've just tried motocalc and it wasn't able to find a suitable configuration for the plane, i'am a bit discouraged because i can't find a working configuration that i can afford, i know that lipo and brushless motors would be great but it's simply too expensive.
Some informations of the model that can be usefull
-Wing surface only 22 dm²
-fuselage 1.40 m long, 16 cm diameter
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Old May 16, 2005, 03:38 PM
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Aix en provence (France)
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I dont know if ducted fan is the good solution in fact , and if a standard geared brusher motor with propeller would not be better even if it's not like on the real plane
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Old May 16, 2005, 03:54 PM
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Lyon (France)
Joined Apr 2004
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You should have a look at the french paper "RCM special Depron" (published last year) They build an Airbus with 2 gws 50. It's a light construction witch seem close to want you want to do.

Bye
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Old May 16, 2005, 03:59 PM
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Thank you Eric to see what is the scale of what i want to build here a comparision with an easystar

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Old May 17, 2005, 09:26 AM
Registered User
Aix en provence (France)
Joined Apr 2005
9 Posts
Hello
I'm on the point of cuting the left wing in foam with an hot wire, but i dont know if i should follow the wing shape of the plan :

Or use another wing shape more adapted to this plane, if there is a better wing shape for my plane
Bye
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Old May 17, 2005, 12:14 PM
Registered User
Aix en provence (France)
Joined Apr 2005
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Finaly i choose a NACA 2415 wing profile, it should be good , or not ... we will see if will ever fly.
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Old May 17, 2005, 02:22 PM
Registered User
Aix en provence (France)
Joined Apr 2005
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After the building of my hot wire i've cut the two wings, but it's just the edge of the wing, not yet the final shape, i'm cutting the gauge of the NACA 2415 profile


Thank you for your advices
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