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Old Feb 04, 2013, 12:23 PM
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France, Aquitaine, Agen
Joined Mar 2009
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Shedofdread :
Thank you for my English, but I'm sure there are many grammar mistakes and word errors, but if you can understand that’s the essential

Wyowindworks, your datas :

I prefer giving you detailed weights because of my errors in the final achievement and reinforcements choosen.

Weigths of the frame’s sandwich skins without before assembly (not glued half shells and accessories):

Wing 31.5gr
Fuselage and tail: 19.8 gr
Horizontal elevator : 6.3 gr

Frame Elements finished :

Wing (included former, spar, horns, ball joints, steel linkages and servo mount without servo): 44.3 gr
Fuselage, including bulkhead, rods linkage, ball joints horns, various reinforcements and battery mount (without geared motor and electronics and servos) : 39.9 gr
Elevator with hinge and clevis: 6.6 gr

So a total weigth frame : 90.8 gr.

I think we can do even more lighter, we can save at least 10 grams!...
As many of us, I always tend to put too much resin with micro balloons when I glued the half-shells (I like to do sturdy ... but at this scale each gram is really important), except for motor bulkhead, the formers are too heavy and strong. As regards the wing, I make same error as the fuselage, I put too much resin and micro balloons. Because the skins are really strong, the wing spar isn’t indispensable, on my next models I’ll replace it by studs which ensure the bottom and top surfaces linkage.

Per dmē this layup (Kevlar 36gr/mē + glass 25gr/mē+honeycomb 1.5mm+glass 25gr/mē gives :

Weight calculated to obtain an estimate before implementation: 2, 2 gr / dmē
Weight achieved with flat test specimen: 3,03 gr /dmē

Weight below are "out of the mold (per dmē)" the halfs parts achieved depending on the complexity of the shape:
For the wing: ~ 3.15 gr/dmē
For the fuselage: ~3.98 gr/dmē
For the elevator: ~ 2.86 gr /dmē

Reading that, you can deduct that the more the shape is complex the harder is to obtain a light frame weigth…

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