toy "helicopters" how do they fly?

Can you supply some pictures to your description?

It's hard to say given your description if this is a helicopter or a gyrocopter, or what exactly.

While they all get their lift by the courtesy of Bernoulli's principle, each of those use a different type of control to manoeuvre

Thanks; I didn't want to use the term gyro copter for fear of...well, you know...probably the same reason they didn't want to put gyro copter on the toy's package. I will attempt to get pic (actual snap shots) when next possible and post it. I was under the impression when I met with the seller that "helicopters" were distinguished by always having swash plates to positively control prop pitch. So, if you can describe how a toy "gryro copter" works...that might be the answer I'm really looking for...?

Gyro or Heli, it simply boils down to: is the main horizontal rotor powered or not?

Okay here's one I found--not the same but it fairly depicts the rotor arrangement described above.

If the upper rotor contraption with airfoil-shaped "bobs" at the ends serves to stabilize &or impart main rotor wing pitch, I can see how it might be possible to turn the craft--in anti-tail-thrust direction, at least--by varying the tail rotor speed. But, pitching the copter tail for forward flight is not as easy to figure.

What say you all?

On a normal Helicopter, constant lift is maintained by the main rotor's wing pitch, and the tail rotor is only there to counter the body's tendency to counter-rotate in the main rotor's direction, while by varying the tail rotor's wing's pitch the degree of this counter-force, is able to control the body's orientation.

That's simply to hover.

- To move forward, the whole main rotor tilts slightly forward, to create a balanced vector, pushing the whole craft forward.

- To move backward, the whole main rotor tilts slightly backward, to create a balanced vector, pushing the whole craft backward.

- To move sideways, the whole main rotor tilts slightly to the right or the left, to create a balanced vector, pushing the whole craft sideways.

- - - - - - - - -

In a Gyrocopter, there's only one powered thrust source - backward facing rotor, to push the craft forward. The main rotor above, is not powered, and is only there, freely rotating by the craft's forward motion against the flow of air, but nevertheless, once rotating, is able to maintain lift, by it's wing's given pitch.

A Gyrocopter's manner of taking-off, landing and flight, is more like that of a fixed-wing aeroplane, unable to lift vertically or move backward or sideways, like a Helicopter.

- Gyrocopter

Yuval, everyone:

Thanks for the details. However, you might have missed where it said the only Rf controls are Main Rotor and Rotor (two sliders), meaning velocity in each case. To my knowledge the main rotor shaft is stationary, unable to pivot--no joystick on the RC unit. So, somehow any tilt of, or tilt force imposed on, the craft must result from interplay between main rotor (assemblage) and the tail rotor. (Hmm, I'm getting that sense that this may be one of those that I eventually figure out just trying to describe it. Anyway...)

I am guessing that (until someone gives a name, let's call it) the gizmo rotor above the main rotor must be the primary mechanism of (direct or indirect) directional control. Why? If the gizmo rotor is taken away, it can be seen that the only controls would consist of rate of ascent (+ or -) and rate of craft rotation about the main rotor shaft (again, + or - as tail rotor velocity is varied). In effect, the only flying mode would be "hover"--whether the craft itself is rotating or not.

Now, it occurs to me that this might be a clue--at least--to how change of direction (change of nose orientation) is (or can be) accomplished--where reorientation of the craft's nose is accomplished (possibly?) only in hover mode. I.e., "bring craft to zero-ground speed (assuming forward motion before that); vary tail rotor velocity to swing the tail one way or t'other; stabilize tail; continue forward." With skill the steering by tail rotor could perhaps be done without slowing to zero ground speed. But, this does not explain how the forward (or backward...although I doubt that) ground speed was attained to begin with. Changing velocity of a fixed tail rotor cannot achieve tail lift (+ or -)...or can it? So, something tells me that the gizmo rotor is the key to fully controlling flight direction (and possibly craft attitude as well). Whereas a "normal" copter uses pitch and roll to effectuate turns, might it be that the toy copter makes only "flat" turns? Or does the gizmo rotor somehow make it possible to advance or turn dynamically by imposing imbalances on the craft, forcing it to pitch and roll?

Back to you....

The gizmo rotor is actually called a flybar. As mentioned above, it provides stability. The mechanism by which it works is actually pretty subtle, but basically its a very simplistic automatic cyclic. Here's a synopsis. If the heli pitches or rolls the flybar comes out of plane with respect to the main rotor (if you play with one you can see that it is free to do that) and adjusts the pitch of (the whole) main rotor (effectively the differential pitch on a real copter) which causes the heli to right itself.

Now that these little choppers are cheap, one of us should try the experiment of locking the flybar and then see how that effects the flight characteristics.

I've seen various versions of these flybars on the micro rc helis. If I recall correctly, on the early ones, say last christmas, the flybar was above the main rotor and looked like a mini rotor that could generate lift. The one I'm holding now has the flybar below the main rotor and it only has a couple of brass weights at the ends.

My dad likes the newer ones better, but I haven't played with it enough yet to decide.

That would be called a 2 ch RC helicopter, which means that you only have control of height and turning with the tail propeller. The more expensive ones are 3 channel and 4. 3 means that you have control over the pitch, making the nose go up and down, and 4 channel is all of the above, and you can roll it to the left or right, like a real helicopter. If you want a 2 ch to go faster, add weight to the front of the helicopter, but it means you won't be able to hover

I bought one of these in a mall in Washington, and spent a lot of time puzzling over the mechanism. It appears that the small piece on the top acts as a gyroscope. Notice the little weights mounted at the tips. Through the linkage, it controls the main blades like the cyclic control on a real helicopter. The feedback is such as to keep the helicopter level so it can hover.

If it is biased a little bit in the forward direction (say by extra weight on the nose of the helicopter) it will tend to drift in that direction. You can steer it where you want it to go by controlling the direction it is pointing using the left and right turning control, which varies the speed of the tail rotor.

I still haven't gotten very good at making it go where I want. It is a challenge just keeping it from bouncing off the ceiling.

Thanks for joining in with practicals, #7.

Before I respond (mostly about the gyro thing) maybe a few clarifications, please?

1. Your description of the remote (at least two controls for turns? in addition to ascend?) implies the craft can be steered left and right, not just one way. Is this true? Have you been able to do so? Does the craft "prefer" one turning direction? (If not yet sure, that's okay.)
2. It was suggested that there's a linkage(s) between gizmo rotor (defined in previous post) and main rotor wings--presumably to control wing pitch(?). The pic above does not show this, nor do I remember there being such a linkage on the craft I saw. Does your craft really have this where it can be seen?
1. Corollary to 2.: On your craft, is the angular position of the gizmo rotor bobs (as in pendulum bobs...at the ends) fixed with respect to distance from main rotor wings? Or can the gizmo rotor rotate with respect to the main rotor? I seem to recall that the gizmo rotor was locked at 90° to the main rotor? (If so, there could be not be a concealed linkage within the main rotor shaft, it seems to me.)
3. Can you clarify just how weight (center of gravity?) is shifted nose-ward on your craft? So as to change bias? I do not recall seeing any such mechanism on the craft I saw.

Thanks again and will be back with better response, and more about gyroscopic) based on the added info. Hopefully we can get this thing pinned down and perhaps illustrated?

Later...but wait, there's one more thing. Your mention of hitting the ceiling with this ultra-light craft was also a problem my friend mentioned. One idea we toyed with was to add payload weight to the craft to slow its responses. For use as a flight operator training aid.... What do you think of that idea?

The model that I have is called MicroCopter - it may be different from yours.

http://gizmodo.com/gadgets/gadgets/palmsize-micro-copter-looks-like-a-bell-jet-ranger-218308.php

1. The control box / charger has two joysticks. The one on the left is vertical and spring loaded to the bottom. It controls the motors (up and down). The joystick on the right is horizontal and is spring loaded to the center. It controls yaw. There are also two buttons next to this control that say "trim" but I don't see any response from them. When I first start out I have to use the L/R joystick to stop it from spinning around. It does seem to prefer turning to the left.

2. The "gizmo rotor" is fixed with respect to the main blades and is offset by a slight angle (I believe it leads the main rotor). It is attached to the shaft at a horizontal pivot (like a seesaw). The side that moves up increases the pitch of the associated blade. When the blade first spins up, the "gizmo rotor" and the main rotor spin in parallel planes (horizontal). If the helicopter starts to tip forward, the "gizmo rotor" stays in a horizontal plane but the main rotor plane tips down in front. This increases the pitch in front and decreases it in back, causing more lift in front to restore the helicopter to an upright orientation. This same effect operates in any direction to stabilize the helicopter.

3. There was a plastic "weight" in the box that the directions said would give "more stable flight". (I haven't put it on). Let me try to clarify what I meant by bias.

If you put extra weight on the front, the stabilizing system will have to provide a counter torque, in other words, more lift in the front. For the main rotor to provide more lift to the front, it has to be sloped slightly forward so the "gizmo rotor" will provide more pitch to the blades in the front. The should cause the helicopter to move in the forward direction. To steer it, then, you need to turn (yaw) the body of the helicopter with the left/right control.

Later...but wait, there's one more thing. Your mention of hitting the ceiling with this ultra-light craft was also a problem my friend mentioned. One idea we toyed with was to add payload weight to the craft to slow its responses. For use as a flight operator training aid.... What do you think of that idea?

I wouldn't add weight. The difficulty I think is that there is a delay between the command to increase height and when the rotor winds up. You just have to learn to anticipate what it needs and get ahead of it. It's sort of like adjusting the water temperature in the shower ... you learn after awhile how much you have to change it without waiting for the result.

#7

I have the Air Hogs version of one of these. Similar to one of the guests above, it has two control sticks and a trim control. Basically the thing will fly mostly straight up and down and rotate left and right when you pull it out of the box. Mine came with some stickers/tape that you can put on the nose to get better forward motion. A friend of mine put a thumbtack in the nose of his (since the body is stryofoam) to provide a little more forward speed than the tape.

The trick seems to be to floor it for about 2-3 seconds to get it up and then let off the main rotor until you reach the height you desire. It is actually harder to control if you ease into the lift. I think this is because the tail rotor is a constant speed (until you use a control to change it). So if you try to lift off slow, your tail rotor over compensates for the torque of the main rotor and you end up spinning around and crashing into things before you get any height.

The trim control seems to control the set speed of the tail rotor. Once you reach a stable height and main rotor output, you can adjust the trim to prevent the helicopter from spinning (guest above mentioned that his likes to turn left). The tricky part to this is that if you increase or decrease the main rotor speed to go up or down, you again change the torque on the helicopter and the constant tail rotor speed will cause you to spin. Sometimes though you can use this to your advantage to make quick turns.

The way to learn is to be in a nice open area with a high ceiling. I learned to fly mine pretty good on vacation because the house had a decent size great room with a cathedral ceiling. Outside is not good because any wind will blow it around. Indoors, turn off the ceiling fan or it will do the same thing. One other tip, I have found that when you know you are about to crash, it is better to just let the thing fall to the ground rather than plowing your rotors into couch or wall or plant or TV or (insert indoor object or person's name here)... I have had a blast with mine and even took it to work to play around with a few times. Good luck and have fun.

I have flown (and crashed) many of these rat bastard addictive toys. Love it. One of the hardest things I have ever learned to do. Here is what I have learned about them:

There are two basic types of R/C helicopters:

1: Two Channel…that is the left stick controls the speed of the main rotor controlling altitude, and the right stick which controls yaw. That's it.

If it is statically loaded to be nose heavy (ever so slightly) it will have a tendency to always travel forward…much like a hovercraft…in order to stop this motion you must quickly turn the craft 180 degrees form the direction of flight which takes quite a bit of skill. If it is neutrally loaded it will just hover or go straight up or down depending on the speed of the main rotor….good luck with that balancing trick.

In my opinion this type is really a waste of time. They are advertised to be easy but I'm thinking…NOT!

2: Four Channel Helis have 4 axis control:

a: Throttle, Collective pitch and/or main rotor speed. Left stick up and down.

b: Yaw. Left stick right and left. (speed of tail rotor)

c. Cyclic Pitch (forward and backward) . Right stick up and down.

d. Cyclic Pitch (right and left). Right stick left and right.

If this is the type of Heli you describe it does have a swash plate of sorts. The small paddles you describe actually control the pitch of the whole main rotor disc.

what about the 3 cannel "toyhelis" then? I have the coaxial Airwolf from Lie Bro. Its very sensetive, and hard to control. But I think the 3 cannel tandem rotors are more stable.

I purchased a 2 channel and found that the main rotor blades werent balanced properly. There is a technique available to balance the blades and should be preformed before any helio maiden flights are performed.