Included with the EVO Flight Mini Stinger

The EVO Flight Mini Stinger includes everything you need to fly, right out of the box. Here’s what is included:

• The EVO Flight Mini Stinger Micro RC Helicopter
• A 2.4 GHz, DSM-2 Spread Spectrum Transmitter (requires 4AA Batteries)
• A Portable Lipo Charger built into the transmitter
• 1 cell 3.7V 110mAh Li-Po Battery

The Evo Flight Mini Stinger is great for beginner and experienced pilots, because you do not have to buy any additional parts. You can use this helicopter to get experience and practice your orientation indoors when you cannot fly outdoors because of the weather.

Main Features of the Evo Flight Mini Stinger Indoor RTF RC Electric Helicopter

Like the Blade MCX the Evo Flight Mini Stinger has a proportional four channel radio. Four channel control means that pilots can fly the helicopter with four dimensions of freedom. The Evo Flight Mini Stinger can fly up/down, rotate left/right, pitch forwards/backwards, and bank left/right. With a four channel radio you can precisely control the Evo Flight Mini Stingers’ movement through all three dimensions. With a rotor size of 188mm (7.4”) and a length of 213mm (8.4”) this helicopter can easily fit in the palm of your hand.

The coaxial rotor design of the EVO Flight Mini Stinger provides this helicopter with great stability, and eliminates the need for a separate tail rotor to control yaw (rotation about the main rotor axis). The main rotors spin in opposite directions, canceling out rotor torque caused by their rotation. Coaxial RC helicopter are great for flying indoors, because of their stability and the precision control provided.

The Evo Flight Mini Stinger uses a tiny 1 cell lithium polymer battery for power. Unlike most micro RC helicopters, the battery is removable and interchangeable. Each cell provides 3.7 volts of power with a capacity of 110 mAh (Milli ampere hours). You charge the battery using the included transmitter, which runs off four “AA” alkaline batteries. A typical charge takes about 30 minutes and provides an average flight time of 6 to 8 minutes. Because the battery is interchangeable, we recommend that you purchase an extra so that you can use one while the other is charging.

Weighing only 1 ounce, the Evo Flight Mini Stinger is virtually crash proof. A sudden drop from a few feet above the ground won’t damage it, and in most cases minor collisions with walls are not a problem. Although it is not indestructible, the Evo Flights durability makes it an ideal present for anyone over 12 years of age.
If you want to get into the exciting world of RC helicopters, the Evo Flight Mini Stinger makes a great starting place. It will show you all the basics of RC helicopter flight, and can be used as a starting place to more advanced models. If you’re already an experienced RC helicopter pilot, you’ll like the Mini Stingers control and stability. Watch our site for tutorials on the Mini Stinger, including a how to for installing replacement parts.

This video depicts the Draganflyer X4 RC Helicopter being quickly set up and flown from its case which has an optional detectable back pack harness.

In this video we see the Draganflyer X4 being transported in its soft pack with back pack harness on a man riding a mountain bike. This truly shows has easy it is to pack the Draganflyer X4 into a remote location.

One of the camera payloads the Draganflyer X4 RC Helicopter can carry is the Panasonic FX-580 12.1 Mega Pixel Digital Still camera. This video gives a good description of how this camera integrates with in the Draganflyer X4 System.

This video gives us a picture in picture of what the camera sees as the rc helicopter is flying. The video is transmitted live while recording to the on board digital video camera.

Another camera payload option for the Draganflyer X4 is a micro video board camera with a on board digital video recorder. This video gives you the details of the Micro Video board camera.

The Draganflyer X4 RC Helicopter, as demonstrated by these videos, is a very versitile and portable UAV aerial video and aerial photography platform. We here at RCHelicopter.com will be looking for new videos from Draganfly Innovations.

The Megatech Micro Flyer includes a charger that is built right into the transmitter. This lets you charge the RC helicopter on the field, maximizing flying time.

A simple to use transmitter operates on the radio band, not the line of sight infra red frequency that is often used with micro helicopters. The transmitter also uses buttons instead of sticks, requiring less skill to operate precisely.

The Megatech Micro Flyer uses a coaxial design, giving it good flight stability. A separate tail rotor is used to control yaw.

The Megatech Micro Flyer is a great, easy to fly electric RC helicopter for beginners. You can read more about it on it’s website

Increase The Speed Of The RC Helicopter

One of the most popular modifications involves increasing the horizontal speed of Micro Mosquito. This can be done in one of two ways:

1. Shift the center of gravity forward - If the balance point of the Micro Mosquito is moved forward, then it will move forward faster. You can do this by adding small weights under the Micro Mosquito’s main rotors. This will result in increased forward speed, but decreased backwards speed.
2. Get a different tail rotor – Standard mini heli tail rotors will fit the Micro Mosquito’s tail motor shaft. Mini heli tail rotors move air more efficiently in one direction than another, so using them on the Micro Mosquito will let you control the pitch in one direction more effectively. Normally, it is better to have more control in the forward (nose down) direction of travel.

Decrease The Weight Of The RC Helicopter

There are a number of ways that you can decrease the Micro Mosquitos weight. Decreasing the weight will provide longer flight times and more performance.

1. Remove the rubber “feet” – You can do this by pulling them off of the Micro Mosquito’s legs.
2. Remove part of the plastic shell – You can unscrew and remove the bottom part of the Micro Mosquito’s body, which will dramatically reduce the weight of the RC helicopter.

Optimize The Radio Range Of The RC Helicopter

The range of the radio transmitter is fine for flying inside a house, but more range is required for flying in a gym or other open area. This is one of the more technical mods, so proceed at your own risk. I have not actually tried this, but this thread on RCGroups.com says it should work. Follow this procedure carefully:

1. Open the transmitter case - Do this by removing the 5 screws found on the back of the transmitter case.
2. Remove the circuit board – Remove the three screws holding the circuit board down, and gently remove it.
3. Remove capacitor C15 – Flip the circuit board over, and look for a capacitor marked C15. It should be on the left side of the circuit board. De solder this capacitor and remove it carefully. There should be no contact between the solder pads where the capacitor used to be.
4. Re install the circuit board – Put the circuit board back on and replace the three screws that you took off earlier.
5. Close up the case – Put the back of the transmitter case back on and screw it in place with the five screws you removed earlier.

Unfortunately, we know very little about this mod or if / why it works. Any comments on this matter would be greatly appreciated.

Remove the Throttle Spring From The Transmitter

Normal radio transmitters do not have a spring restrained throttle. Pilots of larger RC helicopters appreciate the control that not having a throttle spring provides, so here is how you remove it:

1. Open the transmitter case - Do this by removing the 5 screws found on the back of the transmitter case.
2. Find the spring – It should be behind the throttle stick.
3. Remove one of the two screws the spring is attached to – And then put the screw back. You can leave the spring in the case or remove it entirely, it doesn’t really matter.
4. Reassemble the case - Put the transmitter back together using the 5 screws that you removed earlier.

Now the throttle lever will stay where you last left it, so that the Micro Mosquito can hover without constant control input.

Improve Flight Stability and Control

Here are some tips to improve how the Micro Mosquito flies.

1. Tilt the tail rotor – The micro mosquito tends to spin when the throttle is accelerated, sometimes leading to a hard landing. You can fix this problem by twisting the tail boom about 5 degrees to the left (when viewed from behind). Twisting the tail boom is easier if you heat it up slightly beforehand.
2. Add weight to the main rotors - The inertia of the main rotors causes them to self stabilize when spinning. You can increase this tendency by coiling a small amount of very thin wire over the outer rotor wire. Do this twice on opposite sides of one main rotor, and then repeat for the other main rotor. As long as you don’t add too much weight this should improve the RC helicopter’s stability.

Color!

Here are some tips and tricks you can use to personalize your Micro Mosquito:

• Remove the case and spray paint it – take all of the radio components, batteries, and motors out of the Micro Mosquito’s body and spray paint it any color you like.
• Fuel tubing effects – Get a piece of clear fuel tubing from your local hobby store. Then push one end over one of the Micro Mosquito’s green LED eyes. Bend the piece of fuel tubing over, and push it on to the other LED. When the helicopter is turned on, the light should produce a really cool neon tube effect. This is also a great way to move the center of gravity forward, so the helicopter goes faster.
• Insect antenna – Use stiff wire and make a pair of insect antenna. You can glue these to the Micro Mosquito’s body to create an insect appearance. Be sure to keep them away from the main rotors. Just like the fuel tube mod, this will move the center of gravity forward and cause the helicopter to move faster.

Spare Parts / Experiment Pack

Need parts for your Micro Mosquito? RCtoys.com has a great selection and a special package of parts, chosen for easy modification. You can build all sorts of RC vehicles using the micro mosquito and it’s components. Get out your tools and let your imagination soar!

How The Swashplate Works on RC Helicopters

In order for the rotor blades of an RC helicopter to change pitch, there must be a way to transform the linear motion of a servo arm into the rotating motion required by the rotor blades; this is accomplished by using a swashplate. The swashplate is a mechanical device, consisting of two plates mounted to the main rotor shaft. One of these plates is attached to the servo controls and the helicopter body, and the other rotates with the helicopter rotors. As can be seen in the picture, the swashplate transforms the motion of the servo arms into motion of the upper plate. Each rotor is connected to the upper disk of the swashplate, and so they will move as the bottom disk moves. The horizontal rods visible in the picture represent where the servo arms would connect, the number of rods included depends upon the individual helicopter. Every RC helicopter that can change the pitch of its rotor blades will have a swashplate attached to its main axial. There are many different implementations of swashplates, but each follows the same basic design shown in the image. In a conventional RC helicopter, two servos are used to control the swashplate. One servo is used to control the horizontal motion (bank) and the other is used to control the forward and aft motion (pitch).

RC Helicopter Collective Pitch – Climbing and Descending

When a RC helicopter needs to climb or descend, it uses collective pitch. When the command is given for the helicopter to climb, the servos push the entire swashplate upwards. This has the effect of simultaneously increasing the pitch of all the rotor blades. When the pitch is increased, the rotors grab more air as they move, and so lift produced is increased. This increase in lift occurs evenly, so the helicopter does not turn. When the helicopter needs to descend, the swashplate is lowered in the same way. This will decrease the amount of lift produced from the rotor blades.

RC Helicopter Cyclic Pitch – Attitude Control

Changing the bank and pitch of the helicopter requires the swashplate to tilt. This is accomplished by tilting the lower disk of the swashplate. When the lower disk is tilted, the upper disk will also tilt, while it is spinning. The main rotors, which are attached to the upper swashplate will also tilt. In order for this to happen however, each rotor must be given time to “fly up”, or “fly down” to the location where it needs to be. This is accomplished by using pitch links, which provide each rotor with the information of where it needs to go, before it has to be there. The net effect is that the blades move cyclically, and tilt the motion of each rotor in one direction. The swashplate can be tilted in any direction, so the helicopter can change its pitch and bank in proportion to the commands given by the transmitter.

RC Helicopter Cyclic Collective Pitch Mixing (CCPM)

Model RC helicopters can use more than two servos in combination to control the motion of the swashplate. Software running on the rc transmitter (radio) tells each servo how much to move to achieve the desired motion of the RC helicopter. Each linkage to a servo is represented by a silver rod in the above picture. All of these rods are placed equidistant from each other. A swashplate mix refers to the number of linkages attached. For example: a two linkage swashplate would be controlled by two servo rods, placed 180 degrees apart from each other. A three linkage swashplate would use a 120 degree swash plate mix. The swash plate in the picture above has 6 control rods, and so it would use a 60 degree swash plate mix. Most RC helicopters will use a swashplate with between two or four control rods. The largest RC Helicopters use 4 control rods, because of the extra strength they give the swashplate mechanism.

In Summary

• Every RC Helicopter that can change the pitch of its blades has a swashplate.
• The swashplate consists of two disks, one which spins and one that does not.
• The bottom swashplate does not spin, and is connected to the servo control rods.
• The swashplate consists of two disks, one which moves and one that does not.
• To rise or descend, the rotor blades move collectively
• Pitch and bank require the swashplate to move cyclically.
• Pitch links control the position of each blade.

There are different ways that coaxial RC helicopters can be designed.

Coaxial Helicopters – How Do They Work

Besides using the tail rotor to control the yaw, two main rotors can be mounted on the helicopter, and spun at different rates. The difference in thrust causes the helicopters nose to turn. This duel rotor design is used in several full scale helicopters. The CH-47 Chinook is a good example of this duel rotor design, and is frequently used as a military transport helicopter because of its large lifting capacity. RC Helis use the same principle, but most of the time each rotor is mounted on the same axial, hence the term “coaxial”.

Twin rotors that spin in opposite directions

The rotors of a coaxial helicopter need to spin in opposite directions to cancel out the gyroscopic force. On some helicopters, both rotors are mounted on top of each other The main axial of a coaxial helicopter is actually two separate axils. One axial is mounted inside the other. Each sub axial is connected to a gear at the base of the main shaft, and each gear is connected to an electric motor. These two motors operate independently of each other, so the speed of each rotor can be changed.

Since the rotors need to spin in different directions, the top and bottom rotor blades are curved in different directions. This is because each rotor needs to be traveling into the air flow in order to work. The bottom rotor spins in a clockwise direction, and the top rotor spins in a counterclockwise direction.

Two Channel Coaxial RC Helis

It is possible to build a coaxial helicopter so that it only needs two main rotors, and eliminate the tail rotor entirely. Tilting the main rotors forward slightly, results in a constant forward movement. These helicopters are great for beginners due to their simple controls.

Three Channel Coaxial RC Helis

In some coaxial helicopters, a tail rotor is still added. The tail rotor is oriented in the same direction as the main rotors. The forward and reverse rate of the helicopter can be changed, because this system allows pitch control. You can fly forwards, backwards and also hover with this kind of helicopter.

Four Channel Coaxial RC Helis

Even though the coaxial design is most frequently used in small, fixed pitch RC helicopters, it can also be used for models with cyclic collective pitch. The only difference between these models and the conventional designs is their lack of a tail rotor. As with the models above, yaw is controlled by changing the rate at which each rotor spins, but the rotors can change their pitch. This allows the helicopter all four degrees of freedom: pitch, bank, throttle, and yaw. The Esky Lama V4 is good example of the four channel coaxial design.

How The Coaxial Design Benefits RC Helicopters

• Yaw can be controlled by changing the speed of the main rotors, so the pitch can be controlled with the tail rotor.
• The main rotors spin in opposite directions, which gives the helicopter stability.
• Coaxial RC helicopters are a good way to learn how to fly, because they are very stable.

Spare Batteries and Charger:
A good battery is an essential part of your rc helicopter system. Your battery must be able to supply enough power to operate your electronics for at least one entire flight plus a safety reserve. You will need a charger to top up the battery between uses, or have a spare battery to use while the depleted one charges.

Hex and Nut Drivers:
These are essential for maintaining (and also building) your rc helicopter. A good set will last a long time, and make adjusting hard to reach bolts at the flying field easier.

Ball Link Pliers:
Ball link pliers are specially designed to disconnect the ball links on your model. These pliers make disconnecting ball links easier, but the same task can be performed with a pair of needle nose pliers.

Pitch Gauge:
To adjust the pitch of the rc helicopter’s rotor blades, you will need a pitch gauge. Make sure to get one with a large, easy to read scale.

Fuel and Fuel Accessories:
In addition to adequate fuel, a mechanical or electrical fuel pump with a few feet of fuel tubing makes filling easier. Spare silicone fuel tube to replace worn lines, a spare fuel filter, and a spare air filter are good to keep on hand.

Glue/Filler:
When you are flying your model, it is always useful to have some glue to do repairs with. With both CA glue and epoxy you will be prepared for most minor mishaps.

Spare Fasteners and Rotor Blades:
Spare nuts and bolts are needed in case one on your rc helicopter breaks. Keep a small case of these in your field box. Spare rotor blades are very important, because a broken rotor blade can put an end to a practice session.

Field Box:
A field box is ideal to carry all of your tools, fuel, and other accessories in when you fly your rc helicopter.

Having these parts along with you when you go out to fly your rc helicopter can be a great time saver.

Now that we have clarified that, I will show you the general guidelines for building your first rc helicopter model.

The first thing to do when your rc helicopter kit arrives is to not open the box. Do no open the box until you are completely ready to start construction. All of the parts will be packed neatly and efficiently, so if you take them out, you are likely to lose them. Find a place to work on your rc model where it will not be disturbed by dogs, cats, or small children. The work surface should be flat, and large enough to set out all of the rc helicopter components neatly. Refer to the article titled “Basic Tools for RC Helicopter Repair & Maintenance” for a list of the tools you will likely need. Once you have the place, time, and tools to work on your model, you can begin construction.

As you proceed through the instructions, check off each step after you complete it. This way you will not lose your place when you come back. Nuts used in the rc helicopter sometimes have an insert in them that prevents them from vibrating loose while the model is in flight. If they don’t, use blue locktite to secure them. Be sure not to confuse this with red locktite, which is permanent. It is very easy to strip the heads and threads of the different screws that you will be using during assembly. Getting a stripped screw out of its hole is not an easy task, and it is better to simply not over tighten them in the first place.

Ensure that the engine cooling fan is balanced, because if its not, the resulting vibration will affect the entire rc helicopter. If it isn’t perfectly balanced when you get it from the manufacturer, you can correct it with a small amount of sanding. Once installed, make sure that this fan runs true.

It is critical that the mesh between the main gear and the pinion gear is correct. If it is too tight, friction will waste power and wear out both gears. If the mesh is too loose, then the gears will rattle back and forth, causing vibrations and wear in the system. Some rc helicopters are made to such a low tolerance that there is no way to adjust the mesh of the gears. If the rc helicopter allows it, move them in or out until they turn freely, without either friction or excessive play.

When assembling the smaller components of the head, swashplate, and washout unit, be careful to do it accurately. Use locktite to secure all of the bolts, and do not overtighten. Make sure that the resulting parts have freedom of movement and that the control is not sloppy.

Constructing the tail rotor gearbox requires special care. The gears must mesh properly, for the same reasons mentioned above. Align the position of the setscrews so they tighten against the flat spots on the shafts. Some gearboxes provide a way to lubricate the gears after construction. If yours does not, then you will have to lubricate it well before it is sealed. The gears will wear out quickly if you do not apply enough lubricant.

Balancing the tail rotor blades is also important. To do this, mount the blades on the center hub and place the system on a high point balancer. Adjust the balance by sanding, or adding blade covering material. When installing the tail rotor blades, make sure that they are not too loose or too tight. This is essential for smooth operation. They should be tight enough to not fall under their own weight, and loose enough to move freely.

The tail boom can be secured to the fuselage with a small bolt, inserted into a hole drilled into the boom and the main frame. This can prevent the boom coming loose if its attachment to the main frame fails. The horizontal fin does not affect the flight characteristics of the helicopter in any significant way, but the vertical fin does. The vertical fin contributes to the helicopters yaw stability, and it is important to have a large one while learning to fly your model. You can make one with light plywood, but be sure to fuel-proof it. If the fin extends below the tail rotor, and can help protect it.

Fuel tanks are mounted differently between models, but here are some points to consider when mounting your tank:

• Protect the tank from vibration with foam rubber, to prevent the fuel from foaming with small vibrations
• The clunk in the fuel tank should be able to move freely, and should also reach the bottom of the tank
• Fuel filters are good, they can be either attached to the fuel system, or the fuel can filtered before use
• Pressurize the fuel tank by attaching one line to the muffler, this will increase fuel flow
• Adding an extra, or header tank is also fine, but it does not affect the fuel flow to the engine

The blades for your rc helicopter will need to be balanced. This is one of the cheapest and easiest ways to do it:

1. Find the spanwise center of gravity by balancing the leading edge of each blade on a pencil, and then mark the center of gravity.
2. Determine if the balance points on each blade are the same by lining them up. If the balance points match, then no further adjustments are necessary.
3. If the balance points do not match up, then add electrical tape to the tip or root of the blade as required.
4. Mount the blades on a blade balancer to determine their relative weights. These need to be equal, so if they are not, add electrical tape to the centre of gravity of the light blade, until balance is achieved.

The blades of the rc helicopter will have to be made visible, while in flight. You will need to tell between the two different blades, and see the rotor disk. The former can be accomplished by placing different colors of tape on the ends of each blade. The former can require strips of blade covering material, in a color that contrasts the rotor blade, to be applied to both rotor blades.

After the assembly process is complete, you should have a finished model that you can be proud of. Make sure that everything looks right, and enjoy flying your new rc helicopter.

Basic tools that you will need are as follows:

• Standard pair of needle nose pliers
• Screwdrivers, both standard and Phillips
• Hex drivers of various sizes
• Hobby knife with assorted blades
• Rulers – both metric and imperial scale
• Drill – cordless is best
• Sandpaper – several grades
• Glue – thin and thick CA, slow and long cure epoxy
• Soldering iron and solder
• Scissors
• Wire cutters
• Rubber bands
• Grease and light oil
• Loctite to prevent parts from vibrating loose

There are several other, more specialized tools that you may need as well. They are:

• Rotary tool – Extremely useful for grinding, polishing, and sometimes drilling
• Servo tape – Comes in several different thicknesses, double sided and good for securing radio and other components
• Ball link pliers – These make it easy to remove ball links from your servos
• Ball link driver – like hex nut driver, but holds a ball link
• Small screwdrivers – Sometimes really small screws are used in model construction
• Metric tap and die set
• Open end wrenches – you only need the smallest ones
• Toolbox – to carry your tools with you and store them in an organized way

If you have all of the basic tools, and even some of the more specialized ones, you will have a complete toolbox that will help you in both building and repairing your rc heli.

Saskatoon, Saskatchewan (PRWEB) November 20, 2007 — Vanderbilt University in Nashville, TN has successfully used the Draganflyer electric rc helicopter for autonomous vehicle research, involving flight by computer control without human input. The project is called VECPAV (Vanderbilt Embedded Computing Platform for Autonomous Vehicles). VECPAV is intended to create and develop autonomous control systems for unmanned aerial and ground vehicles. These control systems eliminate the need for an operator by substituting intelligent control software and electronics. This research is part of a larger project aimed at improving the design of hybrid systems which use embedded electronics and software to control mechanical devices used in performance-critical and safety-critical applications.

Vanderbilt University in Nashville, TN has successfully used the Draganflyer electric rc helicopter for autonomous vehicle research, involving flight by computer control without human input. The project is called VECPAV (Vanderbilt Embedded Computing Platform for Autonomous Vehicles). VECPAV is intended to create and develop autonomous control systems for unmanned aerial and ground vehicles. These control systems eliminate the need for an operator by substituting intelligent control software and electronics. This research is part of a larger project aimed at improving the design of hybrid systems which use embedded electronics and software to control mechanical devices used in performance-critical and safety-critical applications.

Having autonomous control over a vehicle creates many benefits and removes the need for continuous human input. This could be applied to full size vehicles, allowing cars to drive themselves, or allowing automated vehicles to perform tasks in hazardous conditions. This would eliminate the risks normally faced by an on-board operator. By removing the operator and related systems from the vehicle, it also allows for increased payloads, smaller sizes, and increased mobility.

The VECPAV system uses a sensor tracker to monitor the motion and position of a Draganflyer rc helicopter by using identifier points on the helicopter. The system then analyzes this data and sends commands back to the Draganflyer rc helicopter through a radio control transmitter, telling the Draganflyer rc helicopter to maintain position or move through its flight plan. Videos of Draganflyer helicopters flying autonomously can be found on the VECPAV homepage, and This YouTube Video. In addition to being successfully used to control Draganflyer electric rc helicopters, the VECPAV system has also been implemented on ground based scale model vehicles.

As a result of his efforts on the VECPAV project, team leader Prof. T. John Koo has been recognized with an NSF (National Science Foundation) CAREER Award: Computation Platform for the Design of Hybrid Systems. This award is considered a highly prestigious honor. Prof. T. John Koo is now at Shantou University, China, where he plans to build on and extend what he has achieved at Vanderbilt.

The Draganflyer radio control rc helicopter has also been used in similar projects such as the MIT Aerospace Controls Laboratory’s UAV SWARM Health Management Project and the Stanford Testbed of Autonomous Rotorcraft for Multi-Agent Control. The Draganflyer rc helicopter is well suited for these applications because it is a stable aerial platform with fewer moving parts than a standard rc helicopter. The Quad-Rotor Draganflyer rc helicopter manoeuvres by varying the thrust generated from each of its four rotors. With one rotor at each corner, differential thrust causes the airframe to rotate and change direction. This eliminates the need for the linkages and components used on conventional rc helicopters that vary the pitch of the main rotor blades in order to manoeuvre. With fewer moving parts, there are fewer things to wear out, and less maintenance required. Because it is an electric rc helicopter, the Draganflyer is safe to use indoors. Its small size allows it to be used in smaller areas than conventional rc helicopters. The Draganflyer rc helicopter is manufactured and sold by Draganfly Innovations.

Decreasing thrust on rotors at or near the front will cause the RC helicopter’s nose to drop. This results in a forward tilt and forward motion. The same method can be applied to the rotors on the back or side, allowing the RC helicopter to move backward and side to side. Draganflyer RC Helicopters use quad-rotor design.

More information can be found in Wikipedia’s quad-rotor helicopter article.

When the rc heli’s horizontal main rotor turns generating upward thrust, it also generates torque which causes the helicopter to rotate in the direction opposite to the rotation of the main rotor. This is countered by sideways thrust generated by a vertically mounted tail rotor. An explanation about the way this works can be found in the Antitorque section of the helicopter article on Wikipedia.

Also, by varying the thrust produced by the tail rotor the RC heli can remain in one position, or intentionally rotate clockwise or counter-clockwise.

An example of a conventional RC helicopter is the eXtreme 450 Brushless 3D electric helicopter made by Thunder Power RC. Smaller examples include indoor mini helis and mini bell IR helicopters.

One possible contra-rotating layout has one rotor blade mounted at each end of a long fuselage, as it is for the full scale Boeing CH-47 Chinook, and is known as a tandem rotor. This concept is explained well by the Tandem Rotor article on Wikipedia. Alternatively, both contra-rotating rotors can be placed on the same shaft, resulting in a coaxial design (sharing the same axis). Another good Wikipedia article on Coaxial Rotors explains the theory behind this.

Coaxial rc helicopters are very stable and easy to fly. The Bladerunner series of indoor rc helicopters made by Interactive Toy Concepts, and the ESky Lama V3 and Lama II V4 electric RC helicopters are examples of designs using co-axial rotor blades.