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Title: Foamy with VPP and thrust vectoring Post by: shadman_alam on May 19, 2011, 08:26:19 PM http://www.youtube.com/watch?v=H_xaXVyw9jE&feature=player_embedded#at=355
Title: Foamy with VPP and thrust vectoring Post by: ujjwaana on May 19, 2011, 09:38:02 PM This is much of a 'Tamasha' plane, without any aerodynamics. Why not put a 'Shakira' instead of a mock plane body!... It would not fare well on scale factor as dreaded 'Reynolds Numbers' would make such design practically impossible. Good on small foamies only.
Title: Foamy with VPP and thrust vectoring Post by: SunLikeStar on May 19, 2011, 11:00:44 PM Why not put a 'Shakira' instead of a mock plane body!... ha ha ha! funny video and hilarious comment :giggle:Title: Foamy with VPP and thrust vectoring Post by: Vector on May 20, 2011, 12:14:41 AM Whats so funny about it?? This guy has got skills most of us can only dream of... and he's got the right equipment for it. :thumbsup:
Hmm..wonder how many here could do this :headscratch: Title: Foamy with VPP and thrust vectoring Post by: SunLikeStar on May 20, 2011, 12:55:08 AM Well I for sure, cannot do it, dont want to. I am only interested in planes :thumbsup:
Title: Re: Foamy with VPP and thrust vectoring Post by: PankajC on May 20, 2011, 11:13:12 AM how come it can go backwards?
Title: Re: Foamy with VPP and thrust vectoring Post by: buzz_rc on May 20, 2011, 11:27:07 AM It has a Variable Pitch Prop (VPP) setup. Hence it can go backwards....
Title: Re: Foamy with VPP and thrust vectoring Post by: anwar on May 20, 2011, 11:27:25 AM Read up on "Variable Pitch Propellers" (VPP). It is the same reason why RC helis can hover inverted.
Title: Re: Foamy with VPP and thrust vectoring Post by: rcpilotacro on May 20, 2011, 04:08:12 PM The concept is there in almost all real life aeroplane with a prop. whether reciprocating engine or a turpoprop engine, the concept in these aeroplanes is, the RPM is nearly constant , what changes the thrust is the variable pitch, as you increase the pitch the torque increases the RPM tends to drop and the fuel flow to the engine increases and the RPM is once again maintained constant.
now on landing, these propellers are withdrawn for reverse thrust, in fact some of these aeroplanes can even taxy rearwards, (Of course with a severe restriction on speed). These foamie RC aeroplanes are following the same principle, RPM is near constant and the pitch is varied for forward and rear thrust. the weight is so less that it near instantly travels rearwards. when it does the control inputs are reversed like you control a tail-slide, tailsliding aerodynamics is very complicated and control is difficult because a rear traveling aeroplane is inherently unstable ufff (So much after two day sabbatical) |