Maker Pro
Maker Pro

Micro Chopper

N

Nelson

Jan 1, 1970
0
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?
 
N

Nigel Heather

Jan 1, 1970
0
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
 
F

f825_633

Jan 1, 1970
0
Nelson said:
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?

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....
 
J

jakdedert

Jan 1, 1970
0
Nelson said:
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.

jak
 
K

krw

Jan 1, 1970
0
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.
 
N

Nelson

Jan 1, 1970
0
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.
 
N

Nelson

Jan 1, 1970
0
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 :)
 
K

krw

Jan 1, 1970
0
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.

It seems that many were getting the two confused. You can't have
4-axis control with only two controls.
 
N

Nelson

Jan 1, 1970
0
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

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
:)
 
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