Align 700 dfc tailrotor shaft snaped

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Wenel
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Align 700 dfc tailrotor shaft snaped

Unread post by Wenel » Sun Feb 17, 2013 1:34 pm

Hi all i have recently maiden a new 700dfc trex hi voltage after howering 2 battery packs 5 min into maiden flight the tailrotor shaft snaped clean off where
it steps down 6mm to 5mm. I have now learned in the net off simular problems. Have anyone here also have some simular problems? PLEASE LET ME KNOW. PS THE HELI WERE BUILD BRAND NEW OUT OF THE BOX
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cabeng
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Re: Align 700 dfc tailrotor shaft snaped

Unread post by cabeng » Wed Feb 20, 2013 2:31 pm

it seems Align are aware of this problem , you can get the new upgraded gears (black ones) that are 6mm all the way to the end , it includes a new tail hub , 6mm shaft

Im surprised though as the new DFC kits come with this already?,
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Re: Align 700 dfc tailrotor shaft snaped

Unread post by Mr.T » Thu Feb 21, 2013 8:49 am

Hi Wenel

I work in a R & D office.

A common practise in engineering is to machine a fillet on a shaft when you go down in diameters. ( especially with metal fatigue )
If there's no fillet radius then it has a risk of being a high stress area and it can at times fail at well bellow the yield stress of the material.

I think that that is the main reason why there's been failures on the tail shafts.
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Wenel
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Re: Align 700 dfc tailrotor shaft snaped

Unread post by Wenel » Sun Feb 24, 2013 9:03 pm

Thanks to all for input. I would like to advice new and currend 700 align owners to do the black gear upgrade on tail.
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