Quad+: Power failure and structure

[maxic31]

Hello all !
I'am new on this forum because i'm start my project of multiwii (quad+ Version). I'm waiting for my hardware configuration from hobbyking...
During this long time i'm thinking about some electrical failure during flight.

First question:
I know it is possible to use 2 lipo battery in parallel (3S) with sames specification to power ESCs.
I think it is possible to use 2 big diode (50A) in serial with Lipo to avoid, in case of Dead Lipo, by discharge Lipo1 to Lipo2
Do you agree with me ?

LipoFailure.JPG

Lipo failure

(4.57 KiB) Not downloaded yet

Second question:
If problem occur on ESC or motor during fligth, 3 other engine can compensate power missing ?

My last question is about structure (attached picture). Large line are carbon fiber square tube (10mm x 10mm) and thin line are carbon fiber square tube (3mm x 3mm). What is your feeling about the strength ?

QuadP.jpg

Quad+ structure

(8.58 KiB) Not downloaded yet

My configuration:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6547
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9485
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9012
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idproduct=10045
Software: MultiWii v1.7

Thank's,
Maxime

[noobee]

1. i think this failure mode is not common (lipo spontaneously failing in flight). the more likely case is that the lipos are overdischarged in flight, which can happen with 1 or 2 lipos in parallel.

2. a quad+ cannot sustain flight with even a single motor failure. i think you need 6 motors at the minimum (y6 or hex) among all the supported configs.

3. i think you need some supporting plates to sandwich the main joint. a butt joint with CF and epoxy is not that strong.

[maxic31]

Hey, thank's noobee!

1. Ok then is not usefull to powered Quad with 2 lipo.

2. God help me in this case

3. Oh yes your right. I'll add some plates of wood (2 or 3mm) in order to reinforced the structure.

[cixesa]

2. a quad+ cannot sustain flight with even a single motor failure. i think you need 6 motors at the minimum (y6 or hex) among all the supported configs.

Hello!
I'm a completely newbie and trying to make a quadx by my own.
Reading this posts an idea came into my mind.
A quadx or quad+ configuration in case of one motor failure could continue to flight turing off the opposite motor and reconfiguring itself like an avatar style bicopter?
I know that there should be a different wiring but this couldn't be managed by software just to make it land safely?

is it a crazy idea?
Thank you!
Giorgio