A Helicopter video to see.

Mad Mike wrote:
> Now this is an r/c controlled copter by some kid and you have to see
> what he does with this thing. Maybe those of us who are sim copter
> pilots should try it. I'm not one and would crack it up immediately.
>


I tried a small electric, twin rotor (counter rotating), model, since it's
the most stable. Never demolished it, which can be done in a blink of an
eye, but I discovered there's no such thing as a "relaxing" flight with a
chopper, so sold it a few months later, while it was still intact! Forget
everything about flying fixed wing, and imagine the coordination of juggling
while balancing on a beach ball!
The more conventional heli models (w/tail rotor, etc) are a B***H to fly -
I know one guy that tried over a year, went through a couple grand $, and
still couldn't do much more than a low hover for less than a minute.
Finally got the computer sim for modelers, practiced on it for six months,
then he was able to manage the real thing with only a fatal (to the heli)
crash every third or forth time out. And there's seldom a minor crash with
those things!!
For flying like in the clip, take away all the gyros,
computerized/programmed transmitters, and it'd be a little different story -
but it's still damn impressive regardless...
Always love to watch the "lawnmower" maneuver (my rotorhead buddy said they
program one of the transmitter switches to reverse the collective commands
when doing this, making control a "wee" bit less mind numbing) .. d:->))

Oh yes, they can! I think the Bölkow was the first to do so, be it with some
precautions!! But I guess boB can tell us much more about the this topic.
boB?

Loek

"SnakeEyes" <agalspector.RemoveThis@hotmail.com> schreef in bericht
news:1135225968.659991.89890@f14g2000cwb.googlegroups.com...
>A very neat R/C model.....I felt like swatting it and then stepping on
> it to make sure it was dead : )
>
> Just wondering though.....if they can make a model helo fly upside down
> like that, why they can't do it with the real thing (as far as I know,
> they can't).
>
> Thanks for the clip, Mike.....very much fun!
>
> SnakeEyes
>

Loek wrote:
> Oh yes, they can! I think the Bölkow was the first to do so, be it with some
> precautions!! But I guess boB can tell us much more about the this topic.
> boB?
>
> Loek

Me??? No way. But I have to admit I thought about a way it could be
done. The Rotor system must be the rigid type, everyone knows that.
Then I thought of how to adjust the rotor system to be able to add
negative pitch. Then I thought there should be a way to keep the
collective from moving the blades into negative pitch accidentally. Then
I thought of a gate switch that would enable the pitch to be lowered but
not negative unless a switch was deliberetly (sp) switched on to allow
the collective to move that far. The sensors in the fuel tank would need
to be changed to show fuel either up or inverted. then the.... ,

Then I thought, why the heck would we need to fly inverted anyway. I
already did it, or did I????

http://xs.to/xs.php?f=what_the_h.jpg&h=xs41&d=05320

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

Yeah, you did it anyway!

Mad Mike
"boB" <akita_77REMOVECAPS.RemoveThis@yahoo.com> wrote in message
news:VJuqf.3765$tO4.456@tornado.texas.rr.com...
> Loek wrote:
>> Oh yes, they can! I think the Bölkow was the first to do so, be it with
>> some precautions!! But I guess boB can tell us much more about the this
>> topic. boB?
>>
>> Loek
>
> Me??? No way. But I have to admit I thought about a way it could be
> done. The Rotor system must be the rigid type, everyone knows that. Then
> I thought of how to adjust the rotor system to be able to add negative
> pitch. Then I thought there should be a way to keep the collective from
> moving the blades into negative pitch accidentally. Then I thought of a
> gate switch that would enable the pitch to be lowered but not negative
> unless a switch was deliberetly (sp) switched on to allow the collective
> to move that far. The sensors in the fuel tank would need to be changed to
> show fuel either up or inverted. then the.... ,
>
> Then I thought, why the heck would we need to fly inverted anyway. I
> already did it, or did I????
>
> http://xs.to/xs.php?f=what_the_h.jpg&h=xs41&d=05320
>
> --
>
> boB,
> SAG 70
>
> U.S. Army Aviation (retired)
> Central Texas - 5NM West of Gray Army Airfield (KGRK)

"SnakeEyes" <agalspector RemoveThis @hotmail.com> wrote in message
news:1135225968.659991.89890@f14g2000cwb.googlegroups.com...
> Just wondering though.....if they can make a model helo fly upside down
> like that, why they can't do it with the real thing (as far as I know,
> they can't).

The reasons are many, but in no small part it's down to G forces. For a
start the pilot would never survive the flight.
Other than that, the stresses scale by a power of 2 everytime something
doubles in size. And a rigid blade 6 inches long would be a floppy boom
strike waiting to happen at 20 ft long. Not to mention a full-size
helicopter with a flight time of 10 minutes is useless. A Li-Poly battery
in a miniature r/c helicopter weighs more than the rest of the model itself.
Imagine the size and weight of a battery needed to fly a full-size!
Basically, things just don't scale as we'd expect. A bumble-bee the size
of a human would never be able to fly, etc. That's even before you get
into engineering overheads to provide negative G linkages, fuel and
lubricant pumps, etc.

But, rigid rotor heads, elastomer bearings, etc. have done wonders for
helicopter agility. But they basically do everything they need to do
already well enough.

Si

I think its down to weight ratio (cue Monty Phython's discussion on the
swallow and coconuts!)
forgetting the effects on the G forces and forces of lift etc could the
rotor blades physically support the weight of the helicopter above it rather
then below.

We all know its much easier to carry our groceries with the bags hanging
down from the ends of our arms but try carrying them with the weight above
your head. Apart from the strange looks you may encounter I would imagine
you wouldn't last long before your arms take the strain and I believe that
may be the case with a real aircraft.

Simon is right about the bumble bee and scale. A RC aircraft may be scaled
visually to the real helicoptor but will not be scaled in the physical
weight - probably a hell of a lot lighter.

--
Ibby (The artist formerly known as Chris)

Athlon64 3000+
1Gb PC3200 Ram
Radeon 9800 Pro (128 Mb)
2 x 80Gb HDs
Saitek Evo Force Flightstick
Windows XP SP2

"Simon Robbins" <simon RemoveThis @NOSPAMsjrobbins.demon.co.uk> wrote in message
news:doe667$57s$1$8302bc10@news.demon.co.uk...
> "SnakeEyes" <agalspector RemoveThis @hotmail.com> wrote in message
> news:1135225968.659991.89890@f14g2000cwb.googlegroups.com...
>> Just wondering though.....if they can make a model helo fly upside down
>> like that, why they can't do it with the real thing (as far as I know,
>> they can't).
>
> The reasons are many, but in no small part it's down to G forces. For a
> start the pilot would never survive the flight.
> Other than that, the stresses scale by a power of 2 everytime something
> doubles in size. And a rigid blade 6 inches long would be a floppy boom
> strike waiting to happen at 20 ft long. Not to mention a full-size
> helicopter with a flight time of 10 minutes is useless. A Li-Poly
> battery
> in a miniature r/c helicopter weighs more than the rest of the model
> itself.
> Imagine the size and weight of a battery needed to fly a full-size!
> Basically, things just don't scale as we'd expect. A bumble-bee the size
> of a human would never be able to fly, etc. That's even before you get
> into engineering overheads to provide negative G linkages, fuel and
> lubricant pumps, etc.
>
> But, rigid rotor heads, elastomer bearings, etc. have done wonders for
> helicopter agility. But they basically do everything they need to do
> already well enough.
>
> Si
>
>

Oh I can imagine it is WORK and not play with those things.

Mad Mike
"CRaSH" <sorry RemoveThis @aint-here.spam.com> wrote in message
news:ALyqf.31854$Mi5.3697@dukeread07...
> Mad Mike wrote:
>> Now this is an r/c controlled copter by some kid and you have to see
>> what he does with this thing. Maybe those of us who are sim copter
>> pilots should try it. I'm not one and would crack it up immediately.
>>
>
>
> I tried a small electric, twin rotor (counter rotating), model, since it's
> the most stable. Never demolished it, which can be done in a blink of an
> eye, but I discovered there's no such thing as a "relaxing" flight with a
> chopper, so sold it a few months later, while it was still intact!
> Forget everything about flying fixed wing, and imagine the coordination of
> juggling while balancing on a beach ball!
> The more conventional heli models (w/tail rotor, etc) are a B***H to
> fly - I know one guy that tried over a year, went through a couple grand
> $, and still couldn't do much more than a low hover for less than a
> minute. Finally got the computer sim for modelers, practiced on it for six
> months, then he was able to manage the real thing with only a fatal (to
> the heli) crash every third or forth time out. And there's seldom a minor
> crash with those things!!
> For flying like in the clip, take away all the gyros,
> computerized/programmed transmitters, and it'd be a little different
> story - but it's still damn impressive regardless...
> Always love to watch the "lawnmower" maneuver (my rotorhead buddy said
> they program one of the transmitter switches to reverse the collective
> commands when doing this, making control a "wee" bit less mind numbing) ..
> d:->))
>

On Thu, 22 Dec 2005 13:20:20 +0000 (UTC), "Ibby \(The Artist Formerly
Known as Chris\)" <chris RemoveThis @mwapartnershipNOSPAM.co.uk> wrote:

>I think its down to weight ratio (cue Monty Phython's discussion on the
>swallow and coconuts!)
>forgetting the effects on the G forces and forces of lift etc could the
>rotor blades physically support the weight of the helicopter above it rather
>then below.
>
>We all know its much easier to carry our groceries with the bags hanging
>down from the ends of our arms but try carrying them with the weight above
>your head. Apart from the strange looks you may encounter I would imagine
>you wouldn't last long before your arms take the strain and I believe that
>may be the case with a real aircraft.

Then again, millions of people are used to carry -sometimes enormous-
loads on their head, in Asia and Africa. Very practical indeed, since
they have their hands free...

>Simon is right about the bumble bee and scale. A RC aircraft may be scaled
>visually to the real helicoptor but will not be scaled in the physical
>weight - probably a hell of a lot lighter.

Not "probably". There is actua science and algebra involved there...



--
Groeten,
Boudewijn.

On 21 Dec 2005 20:32:48 -0800, SnakeEyes wrote:

> Just wondering though.....if they can make a model helo fly upside down
> like that, why they can't do it with the real thing (as far as I know,
> they can't).

Oh they can and I've seen em do it. I've even caught them on camera during
the show at Biggin Hill, UK.

But the most amazing "trick" of all is seeing a Westland Lynx (or any other
helo for that matter) flying backwards, then dropping the tail until it's
fully upside-down and then diving down nose first to pull up again!
That was the coolest thing I have ever seen!

--

Marcel (SAG-21)
(It's good to be the king! - Mel Brooks)