Micro Chopper

N

Nelson

Guest
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

--
Nelson
 
Which one have you got. As you say it has a seperate motor for the tail
then it's a reasonably advanced one. - the real simpl ones have no tail
rotor but have two contra-rotating main rotors instead.

So guessing, I'm assuming it is fixed pitch so will have the following
controls

1 - Main Rotor speed - on a collective pitch hello this will also do the
rotor pitch
2 - Cyclic (Elevator) - tips main rotor back and forward
3 - Cyclic (Aileron) - tips main rotor left and right
4 - Tail Rotor Speed - moves tail left and right

There will also be a gyroscope which is driving the tail.

Cheers,

Nigel


"Nelson" <nelson@nowhere.com> wrote in message
news:0001HW.C57A2C4B00C15D53F0182648@news.astraweb.com...
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

--
Nelson
Click to expand...
 
Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?
Click to expand...
My son has one of these type too (I wont let him near my
Nitro Heli )

The pitch of the blades are fixed so the higher the speed of
the motor the higher it goes which also provides forward
motion. The tail rotor stabilises as in the real thing and
bigger heli's and provides turn. Ingenious....
 
Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
Click to expand...
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

jak
 
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net> wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.
Click to expand...
That still leaves "right and left directionality".


--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

12 of the finest (unintentional) double-entendres ever aired on TV and radio

1. Ted Walsh - Horse Racing Commentator - 'This is really a lovely horse. I once rode her mother.'
2. New Zealand Rugby Commentator - 'Andrew Mehrtens loves it when Daryl Gibson comes inside of him.'
3. Pat Glenn, weightlifting commentator - 'And this is Gregoriava from Bulgaria . I saw her snatch this morning and it was amazing!'
4. Harry Carpenter at the Oxford-Cambridge boat race 1977 - 'Ah, isn't that nice. The wife of the Cambridge President is kissing the Cox of the Oxford crew.'
5. US PGA Commentator - 'One of the reasons Arnie (Arnold Palmer) is playing so well is that, before each tee shot, his wife takes out his balls and kisses them ..... Oh my god !! What have I just said??'
6. Carenza Lewis about finding food in the Middle Ages on 'Time Team Live' said: 'You'd eat beaver if you could get it.'
7. A female news anchor who, the day after it was supposed to have snowed and didn't, turned to the weatherman and asked, 'So Bob, where's that eight inches you promised me last night?' Not only did HE have to leave the set, but half the crew did too, because they were laughing so hard!
8. Steve Ryder covering the US Masters: 'Ballesteros felt much better today after a 69 yesterday.'
9. Clair Frisby talking about a jumbo hot dog on Look North said: 'There's nothing like a big hot sausage inside you on a cold night like this. '
10. Mike Hallett discussing missed snooker shots on Sky Sports: 'Stephen Hendry jumps on Steve Davis 's misses every chance he gets.'
11. Michael Buerk watching Philippa Forrester cuddle up to a male astronomer for warmth during BBC1's UK eclipse coverage remarked: 'They seem cold out there, they're rubbing each other and he's only come in his shorts.'
12. Ken Brown commentating on golfer Nick Faldo and his caddie Fanny Sunneson lining-up shots at the Scottish Open: 'Some weeks Nick likes to use Fanny, other weeks he prefers to do it by himself.'
 
Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net> wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".
Click to expand...
The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
 
On Mon, 05 Jan 2009 20:10:09 -0000, Ron Johnson <ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net> wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.
Click to expand...
I'm still not sure how it would differentiate between moving left and turning left. The OP suggested there were seperate controls for these.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

A guy says, "I remember the first time I used alcohol as a substitute for women."
"Yeah what happened?" asked the other.
The first guy replies, "Well, I got my penis stuck in the neck of the bottle."
 
On Mon, 05 Jan 2009 20:10:09 +0000, Ron Johnson
<ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net> wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
To the OP - I assume you meant right and left motion when he said
Click to expand...
right and left turns (ie, the direction of the helicopter remains the
same, but it moves to the right or left). To me, rotate means face a
different direction which you and others have said is controlled by
varying the speed of the tail rotor. I have a small helicopter that
has servos to control the pitch of the rotor just like a "real"
helicopter. Are you sure yours doesn't?
 
In article <op.unav35e84buhsv@fx62.mshome.net>, none@spam.com
says...>
On Mon, 05 Jan 2009 20:10:09 -0000, Ron Johnson <ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net> wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

I'm still not sure how it would differentiate between moving left and turning left. The OP suggested there were seperate controls for these.
Click to expand...
Ever hear of "Google" or "Wikipedia" (or for that matter
configuring your newsreader properly), dummy? Helicopters have two
main controls (each with two axis of control) the "collective" and
"cyclic". The "collective" controls the overall pitch of the main
rotor for the complete blade rotation (thus the up/down movement of
the chopper) and the pitch of the tail rotor (the rotational
velocity of the chopper). The "cyclic" controls the pitch of the
main rotor during the rotation (or cycle), thus the thrust produced
by the main rotor during the rotation. Increase the pitch of the
blade when it's behind the CoG and the nose pitches down, to the
left and the bird pitches right,.... It's really very simple,
until some damn fool starts the engine.
 
On Mon, 5 Jan 2009 16:38:43 -0500, krw wrote
(in article <MPG.23cc398f1c7092b9897ae@news.individual.net>):

In article <op.unav35e84buhsv@fx62.mshome.net>, none@spam.com
says...
On Mon, 05 Jan 2009 20:10:09 -0000, Ron Johnson <ron@lunevalleyaudio.com
wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

I'm still not sure how it would differentiate between moving left and
turning left. The OP suggested there were seperate controls for these.

Ever hear of "Google" or "Wikipedia" (or for that matter
configuring your newsreader properly), dummy? Helicopters have two
main controls (each with two axis of control) the "collective" and
"cyclic". The "collective" controls the overall pitch of the main
rotor for the complete blade rotation (thus the up/down movement of
the chopper) and the pitch of the tail rotor (the rotational
velocity of the chopper). The "cyclic" controls the pitch of the
main rotor during the rotation (or cycle), thus the thrust produced
by the main rotor during the rotation. Increase the pitch of the
blade when it's behind the CoG and the nose pitches down, to the
left and the bird pitches right,.... It's really very simple,
until some damn fool starts the engine.
Click to expand...
Thanks for your friendly help. However if you look into this a little
less superficially you will find that the flight controls and rotor
configurations on many, if not most, RC model helicopters differ
substantially from those of actual helicopters.

--
Nelson
 
On Mon, 5 Jan 2009 15:30:07 -0500, greenpjs@neo.rr.com wrote
(in article <i6r4m45sk2jhgl98sguheegmvc5nms5qlf@4ax.com>):

On Mon, 05 Jan 2009 20:10:09 +0000, Ron Johnson
ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
To the OP - I assume you meant right and left motion when he said
right and left turns (ie, the direction of the helicopter remains the
same, but it moves to the right or left). To me, rotate means face a
different direction which you and others have said is controlled by
varying the speed of the tail rotor. I have a small helicopter that
has servos to control the pitch of the rotor just like a "real"
helicopter. Are you sure yours doesn't?
Click to expand...
Well, the Chinglish instructions that came with it are not that clear
:) What do you expect for $25 :)

The "trim" buttons control right and left rotate about the main rotor
axis and are used to stop it from spinning out of control. At least
that's their intent. There is a separate joystick which is labeled "L
and R". I can't get the thing to fly well enough or long enough to
determine exactly what that button actually does but my impression is
that it causes the helicopter to fly in a circle clockwise or counter
clockwise. So you set a fixed tail rotor speed with the "trim" buttons
and then vary it slightly with the joystick to get the left or right
circling motion as someone else stated above.

There are only two motors. The main rotor motor and the small one that
spins the tail rotor. The only degree of freedom there is speed of
rotation. The pitch of the main rotor is not under direct user control
and appears to be controlled by a mechanical linkage that is attached
to a rotating inertial dumbell "blade" above the main rotor.

I have since looked at many RC Model Helicopter sites (eg
http://www.rchelicopters.net/) and can see that the more you pay, the
more controls you get and the more the model behaves like the real
thing.

In the case of the little one, the marvel is not how well it flies but
that it flies at all :)

--
Nelson
 
Nelson wrote:
On Mon, 5 Jan 2009 15:30:07 -0500, greenpjs@neo.rr.com wrote
(in article <i6r4m45sk2jhgl98sguheegmvc5nms5qlf@4ax.com>):

On Mon, 05 Jan 2009 20:10:09 +0000, Ron Johnson
ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.
That still leaves "right and left directionality".
The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
To the OP - I assume you meant right and left motion when he said
right and left turns (ie, the direction of the helicopter remains the
same, but it moves to the right or left). To me, rotate means face a
different direction which you and others have said is controlled by
varying the speed of the tail rotor. I have a small helicopter that
has servos to control the pitch of the rotor just like a "real"
helicopter. Are you sure yours doesn't?


Well, the Chinglish instructions that came with it are not that clear
:) What do you expect for $25 :)

The "trim" buttons control right and left rotate about the main rotor
axis and are used to stop it from spinning out of control. At least
that's their intent. There is a separate joystick which is labeled "L
and R". I can't get the thing to fly well enough or long enough to
determine exactly what that button actually does but my impression is
that it causes the helicopter to fly in a circle clockwise or counter
clockwise. So you set a fixed tail rotor speed with the "trim" buttons
and then vary it slightly with the joystick to get the left or right
circling motion as someone else stated above.

There are only two motors. The main rotor motor and the small one that
spins the tail rotor. The only degree of freedom there is speed of
rotation. The pitch of the main rotor is not under direct user control
and appears to be controlled by a mechanical linkage that is attached
to a rotating inertial dumbell "blade" above the main rotor.

I have since looked at many RC Model Helicopter sites (eg
http://www.rchelicopters.net/) and can see that the more you pay, the
more controls you get and the more the model behaves like the real
thing.

In the case of the little one, the marvel is not how well it flies but
that it flies at all :)

They actually fly quite well once you get the hang of it, which
Click to expand...
requires a very delicate touch on the sticks. The chopper you describe
doesnt normally fly forwards, it merely hovers. The rotors 'fly' level
due to centrifugal force and the chopper just hangs below on the clever
gimbal like arrangement.

As I said earlier, you can try experimenting by sticking small air
deflectors either side of the fuselage to send some of the down wash
backwards. Adhesive tape will do. On some models a little nose weight
will give you forward motion.

Ron
 
In article <cO-dnatqp5AG2v7UnZ2dnUVZ8uOdnZ2d@bt.com>,
Ron Johnson <ron@lunevalleyaudio.com> wrote:
In the case of the little one, the marvel is not how well it flies but
that it flies at all :)

They actually fly quite well once you get the hang of it, which
requires a very delicate touch on the sticks. The chopper you describe
doesnt normally fly forwards, it merely hovers. The rotors 'fly' level
due to centrifugal force and the chopper just hangs below on the clever
gimbal like arrangement.

As I said earlier, you can try experimenting by sticking small air
deflectors either side of the fuselage to send some of the down wash
backwards. Adhesive tape will do. On some models a little nose weight
will give you forward motion.
Click to expand...
Yes - mine included a selection of stick on weights for this purpose.

--
*Gargling is a good way to see if your throat leaks.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
On Tue, 06 Jan 2009 11:16:09 -0000, Nelson <nelson@nowhere.com> wrote:

On Mon, 5 Jan 2009 15:30:07 -0500, greenpjs@neo.rr.com wrote
(in article <i6r4m45sk2jhgl98sguheegmvc5nms5qlf@4ax.com>):

On Mon, 05 Jan 2009 20:10:09 +0000, Ron Johnson
ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
To the OP - I assume you meant right and left motion when he said
right and left turns (ie, the direction of the helicopter remains the
same, but it moves to the right or left). To me, rotate means face a
different direction which you and others have said is controlled by
varying the speed of the tail rotor. I have a small helicopter that
has servos to control the pitch of the rotor just like a "real"
helicopter. Are you sure yours doesn't?


Well, the Chinglish instructions that came with it are not that clear
:) What do you expect for $25 :)

The "trim" buttons control right and left rotate about the main rotor
axis and are used to stop it from spinning out of control. At least
that's their intent. There is a separate joystick which is labeled "L
and R". I can't get the thing to fly well enough or long enough to
determine exactly what that button actually does but my impression is
that it causes the helicopter to fly in a circle clockwise or counter
clockwise. So you set a fixed tail rotor speed with the "trim" buttons
and then vary it slightly with the joystick to get the left or right
circling motion as someone else stated above.

There are only two motors. The main rotor motor and the small one that
spins the tail rotor. The only degree of freedom there is speed of
rotation. The pitch of the main rotor is not under direct user control
and appears to be controlled by a mechanical linkage that is attached
to a rotating inertial dumbell "blade" above the main rotor.

I have since looked at many RC Model Helicopter sites (eg
http://www.rchelicopters.net/) and can see that the more you pay, the
more controls you get and the more the model behaves like the real
thing.

In the case of the little one, the marvel is not how well it flies but
that it flies at all :)
Click to expand...
Sounds like the "trim" control I had on a radio controlled car. It's to adjust the steering (or in your case the tail rotor speed) so everything is in a straight line, sort of like a calibration. The LR joystick will be sending the same signal to the chopper.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

Bumper sticker seen on a B-2 Stealth Bomber:
"IF YOU CAN READ THIS, THEN WE WASTED 50 BILLION BUCKS."
 
In article <0001HW.C588A05F005E932CF0182648@news.astraweb.com>,
nelson@nowhere.com says...>
On Mon, 5 Jan 2009 16:38:43 -0500, krw wrote
(in article <MPG.23cc398f1c7092b9897ae@news.individual.net>):

In article <op.unav35e84buhsv@fx62.mshome.net>, none@spam.com
says...
On Mon, 05 Jan 2009 20:10:09 -0000, Ron Johnson <ron@lunevalleyaudio.com
wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.

That still leaves "right and left directionality".

The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

I'm still not sure how it would differentiate between moving left and
turning left. The OP suggested there were seperate controls for these.

Ever hear of "Google" or "Wikipedia" (or for that matter
configuring your newsreader properly), dummy? Helicopters have two
main controls (each with two axis of control) the "collective" and
"cyclic". The "collective" controls the overall pitch of the main
rotor for the complete blade rotation (thus the up/down movement of
the chopper) and the pitch of the tail rotor (the rotational
velocity of the chopper). The "cyclic" controls the pitch of the
main rotor during the rotation (or cycle), thus the thrust produced
by the main rotor during the rotation. Increase the pitch of the
blade when it's behind the CoG and the nose pitches down, to the
left and the bird pitches right,.... It's really very simple,
until some damn fool starts the engine.

Thanks for your friendly help. However if you look into this a little
less superficially you will find that the flight controls and rotor
configurations on many, if not most, RC model helicopters differ
substantially from those of actual helicopters.
Click to expand...
It seems that many were getting the two confused. You can't have
4-axis control with only two controls.
 
On Tue, 6 Jan 2009 06:59:19 -0500, Ron Johnson wrote
(in article <cO-dnatqp5AG2v7UnZ2dnUVZ8uOdnZ2d@bt.com>):

Nelson wrote:
On Mon, 5 Jan 2009 15:30:07 -0500, greenpjs@neo.rr.com wrote
(in article <i6r4m45sk2jhgl98sguheegmvc5nms5qlf@4ax.com>):

On Mon, 05 Jan 2009 20:10:09 +0000, Ron Johnson
ron@lunevalleyaudio.com> wrote:

Peter Hucker wrote:
On Sat, 27 Dec 2008 05:48:54 -0000, jakdedert <jakdedert@bellsouth.net
wrote:

Nelson wrote:
So I got my kid (well, OK, I wanted to try it out too) one of these for
Christmas. As far as I can tell there are only two motors, one for the
main rotor and one for the tail rotor. Yet there are controls for
throttle, right and left rotate, and right and left directionality.
How can you get that many degrees of freedom from speed controlling
only two motors? I get that the throttle controls the main rotor and
makes it go up and down and am guessing that the rotate control is some
kind of stepper that modulates the speed of the tail rotor. But right
and left turns have me stumped.

Any one else have one of these?

The left/right turns requires the understanding that, without the tail
rotor, the entire craft would spin because of the rotation of the main
rotor. The tail rotor counters that. The speed of the tail rotor
either over-corrects, resulting in a turn in one direction; or
under-corrects, resulting in a turn in the other.

When the speed of the tail rotor exactly balances the craft's natural
tendency to spin, the result is straight-ahead flight.
That still leaves "right and left directionality".
The better ones are trimmed slightly 'nose down' or have small vanes or
deflectors either side of the fuselage to deflect a proportion of the
downwash backwards to make it fly slowly forwards. Stearing is by
varying the tair rotor speed.

Ron
To the OP - I assume you meant right and left motion when he said
right and left turns (ie, the direction of the helicopter remains the
same, but it moves to the right or left). To me, rotate means face a
different direction which you and others have said is controlled by
varying the speed of the tail rotor. I have a small helicopter that
has servos to control the pitch of the rotor just like a "real"
helicopter. Are you sure yours doesn't?


Well, the Chinglish instructions that came with it are not that clear
-) What do you expect for $25 :)

The "trim" buttons control right and left rotate about the main rotor
axis and are used to stop it from spinning out of control. At least
that's their intent. There is a separate joystick which is labeled "L
and R". I can't get the thing to fly well enough or long enough to
determine exactly what that button actually does but my impression is
that it causes the helicopter to fly in a circle clockwise or counter
clockwise. So you set a fixed tail rotor speed with the "trim" buttons
and then vary it slightly with the joystick to get the left or right
circling motion as someone else stated above.

There are only two motors. The main rotor motor and the small one that
spins the tail rotor. The only degree of freedom there is speed of
rotation. The pitch of the main rotor is not under direct user control
and appears to be controlled by a mechanical linkage that is attached
to a rotating inertial dumbell "blade" above the main rotor.

I have since looked at many RC Model Helicopter sites (eg
http://www.rchelicopters.net/) and can see that the more you pay, the
more controls you get and the more the model behaves like the real
thing.

In the case of the little one, the marvel is not how well it flies but
that it flies at all :)

They actually fly quite well once you get the hang of it, which
requires a very delicate touch on the sticks. The chopper you describe
doesnt normally fly forwards, it merely hovers. The rotors 'fly' level
due to centrifugal force and the chopper just hangs below on the clever
gimbal like arrangement.

As I said earlier, you can try experimenting by sticking small air
deflectors either side of the fuselage to send some of the down wash
backwards. Adhesive tape will do. On some models a little nose weight
will give you forward motion.

Ron
Click to expand...
Mine comes with a downward pointing "fin" that slides along the rear
boom. It allows you to change the center of gravity resulting in
forward or backward motion... or, more usually, out of control crashing
:)

--
Nelson
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top