When I was a kid, I couldn’t understand why someone would spend 100’s of hours building a scale model then get up the nerve to fly it.

That was until I put together my first RC helicopter and realized building them is as much fun as flying them.

Planning, creating, machining, building and sculpting a scale model RC helicopter from scratch is a lot of fun and the sense of accomplishment when everything fits together and looks just right is huge.

Scale RC helicopters are simply RC helicopters modeled after a full scale real life helicopter.

Scale RC helicopters can come in all sizes from 1/30th scale to 1/4 scale. The larger it is the more realistic you can make it look and the more realistic it will fly, but as the size increases the costs to build it increase significantly.

Some popular scale RC helicopter models you’re likely to come across are the Airwolf, Chinook, Bell UH1, Jet Ranger and the Huges 500.

Good scale RC helicopters aren’t only designed to look like a full sized heli, but they’re also designed to fly and perform like one as well.

Around the country and across the world there are scale model competitions where scratch built scale models are judged based on how closely they resemble the full sized helicopter they’re modeled after.

Many competition scale modelers will even get every single detail perfect not just on the outside, but on the inside of the cockpit as well.

Scale RC helicopters and other aircraft are also often used in movies, especially lower budget productions, because when they’re up in the air, it’s nearly impossible to tell the difference in real life, let alone on film.

Putting together a scale model can be as simple as buying a scale model kit from your local hobby store or as complicated as creating everything from scratch and modeling it off a real full scale helicopter right down to the chipped paint.

If you’re going to go the route of purchasing a scale model kit or scale fuselage some come 100% ready to go with paint schemes and all – you just need to install it.

There are also kits that provide the bare bones and it’s up to you to put it together, make the proper cutouts and prime and paint the fuselage.

If you’re just starting out with scale heli’s or want the look of one without the work, a pre-assembled and painted kit may be the way to go.

But if you want a more custom look without the cost and time needed to fabricate a custom design a good base kit may be the way to go.

Or if you’re skilled and up for a challenge you can build a scale model from scratch.

Extreme scale modelers have been know to design the entire scale model RC helicopter from scratch, but most use an existing airframe as a base and design a fuselage around it.

Building a scale RC helicopter model from the ground up often involves finding a picture of a full sized helicopter to model everything off of right down to the paint scheme and wear and tear.

Everything from the main rotors to the skids to the tail rotor must be proportional to the rest of the helicopter. So, if you’re working off a picture, often you can find the sizes of the helicopter you’re modeling online somewhere, though sometimes you’ll only be able to come up with the length, width height and main rotor diameters of the helicopter, so you’ll need to use those measurements as a reference to calculate the size of the other parts.

Building a scale RC helicopter model from scratch might include everything from making fiberglass molds to machining aluminum, steel and carbon fiber using a CNC machine or hand tools.

Wood is also often used as structural reinforcements because of its strength, elastic properties, light weight and because it’s easy to work with.

Another important thing you’ll want to work into your scale model is proper realistic looking lighting. Many hobby stores, both online and offline sell lighting kits that can be plugged right into your receiver to accomplish that, or if you have a little soldering and electronics skills, you can pick up a few LED’s at an electronics shop and make your own.

Dimension Engineering sells a switch called the pico switch that can be hooked up to your receiver and controlled from your radio to turn lights on and off. They also have LED lighting kits available for scale modeling.

The basic RC helicopter needs a 6 channel radio: three channels for the cyclic, one for the rudder, one for the gyro gain and one for the throttle.

Because scale RC helicopters often have extra’s like landing gear and lights that you’ll want to be able to control from your radio transmitter, as a minimum you’ll need a 9 channel radio, though a 12 channel would be preferable and a 14 channel would be super.

Because full scale helicopters don’t use flybars, many scale model RC helicopters use flybarless systems like the popular Mikado vBar flybarless system or the Skookum Robotics SK360.

If you can afford it, a turbine powered heli makes a great scale RC helicopter model because it works and sounds just like a life sized helicopter.

If a turbine RC helicopter is a little out of your price range or skill set, there’s a company called Aerosound RC that produces sound systems for your RC heli that sounds just like a turbine powered helicopter. It even connects to your throttle channel and gives accurate spool ups and downs.

Most scale RC helicopter pilots set their gyros to rate mode because it lends itself to a more realistic looking flight experience.

Unless you’re using an off the shelf fuselage to fit on the frame of your existing RC heli, most scale RC helicopters aren’t set up for 3D flying. There’s a copy of reasons for this:

1. Full scale helicopters don’t do 3D.

2. Often custom built scale helicopters are heavy and can’t stand up to 3D flight.

Powerful buy slower servos are usually used when compared to your average RC helicopter and the cyclic speed, range, pitch curves are often a fraction of what you’ll find on an all out 3D RC helicopter. If you’ve every tried flying a scale RC helicopter in a simulator, you’ll note how slow and sluggish it is when maneuvering.

There’s another reason for the slower response times and pitch ranges - you’re a lot less likely to crash. A simple crash can mean 10’s or 100’s of hours of lost work or complete devastation of your model.

If you’re considering going to scale, something to keep in mind is its addictive, very addictive, and once you go scale model building, it’s hard to go back

So what’s a gyro? In lamans terms, it’s a device that can sense and measure rotation or how quickly an object turns.

In helicopters, gyros are typically used to dampen the tail movements or in the case of the heading hold gyro, to keep the tail in a constant position.

However, the modern RC helicopter gyro isn’t really a gyroscope at all – it’s an accelerometer. Accelerometers produce a signal as they’re rotated about an axis just like a traditional gyro and the more it accelerates, the stronger the signal is.

For the purposes of this article and real life, we’ll still refer to accelerometers as gyros because they function similarly and the end result is much the same.

On your RC helicopter, gyros work by measuing yaw or rotational acceleration, then mixing that with the pilots rudder commands to add dampening to your helicopters yaw axis rotation. For example, if a gust of wind makes your helicopter turn counterclockwise in the yaw axis, the gyro senses this and moves the tail rotor in the opposite direction to slow or dampen the rotation.

The are three main types of gyros:

1. The first is the mechanical rate gyro uses an electric motor to spin a small disc or flywheel that can pivot on one axis and has springs to return it to center. When the gyro was moved about the axis that it’s sensitive to, the spinning disc tilts and this tilt is picked up electronically by a ptentiomenter.

The faster the gyro is rotated, the greater the deflection is and based on the deflection, the corrective signal can be fed into a servo.

(Mechanical gyro)

2. The second type of gyro is the piezoelectric gyro which uses a quickly vibrating crystal. As the crystal vibrates, an applied rotational force will casue disturbances in it’s wobble which create a small, but measurable electric current proportional to the rate at which the gyro is rotated.

The piezo element is similar to that used in a gas lighter system like those found on a barbeque.

Piezo electric gyros are much more sensitive than a mechanical gyro and because there are no moving parts, they are a lot smaller.

(Piezoelectric gyro)

A disadvantage of piezoelectric gyros systems is that they’re very temperature sensitive and going from hot to cold or vice versa will casue them to act erradictly. Most have built in temperature protection circuits, but they’re not perfect, so if you’re going to take a gyro from warm your car and fly in cold weather, give it 10 or 15 minutes to adjust before flying.

3. And the third and most modern type of gyro is the MEMS or Micro Electric-Mechanical System gyro.

MEMS are molecule sized machines that are fabricated on top of a piece of silicon, along with the electronics to interface to them. They vibrate at a high rate just like the piezoelectric gyro and the As the gyro rotates, so does the displacement of the mass and the signal generated by the gyro.

(Mems gyro)

Besides the different makups and types of gyros, there are two primary ways that gryo’s operate, rate and heading hold mode.

Rate Mode Vs. Heading Hold Gyros

There are two types of gyro functions, rate mode and heading hold.

Rate Gyros

Rate gyro’s are often used in scale RC helicopters because they lend themselves to a more realistic flying experience, while heading hold gyros are used by almost eveyone else because they make flying easier.

Rate gyros only sense the turn rate or angular acceleration of your helicopter, not the absolute orientation of the helicopter and do not provide a heading hold capability. For example, once the helicopter has been turned, it cannot return the helicopter to the original orientation, nor keep the helicopter facing a constant direction.

Rate gyros will simply control your RC heliecopter’s tail servo so as to resist rotation in the direction they measure. In other words, it “dampens” the tail movement.

Because a rate gyro “slips” when trying to counteract the main rotor’s thrust, it can’t effectively counteract the main rotor’s thrust on it’s own.

The amount of thrsust provided by the tail is set by the revo mixing function on your radio transmitter.
Revo mixing allows you to set the tail rotor thrust to match the throttle curve so that it exactly counters the main rotor’s thrust. There’s no formula for setting the values – they must be set by experience and trial and error.

Heading Hold Gyros

Heading hold or heading lock gyros are a conceptually simple extension of rate gyros.

In a heading hold gyro, a built microprocessor that keeps track of and remembers how far the helicopter has turned from its set position. Based on the deflection from the set position, the gyro will control the rudder servo such that the gyro returns the helicopter to the set position.

Therefore, as you increate the throttle or headspeed of your heli, the holding hold gyro will counter the main rotors thrust automatically keeping your heli’s tail in its original position.

Heading hold gyros are very popular and pretty much standard amoung RC helicopter pilots for that very reason - they’ll hold your tail in a constant position no matter what you’re doing as long as you don’t input a rudder command, even if you’re doing 3D aerobatics or flying in a strong wind.

With a heading hold gyro, the rudder signal from your transmitter no longer directly controls the tail – it simply tells the gyro how many degrees to turn per second. It will also reset the gyros stored position to the new position you move your heli to. Revo mixing on your radio must be disabled when using heading hold gyros.

In conclusion, unless you’re going scale, and are looking for the more real characterstics often associated with scale RC helicopter flight, you’ll want to purchase a heading hold gyro, preferrably of the piezoelectric or MEMS variety unless.

Time: ~15 mins.

Tools Required: Small screwdriver or hex driver (to remove servo screws), flathead screwdriver, tape, white grease (optional)

Parts Needed: Replacement servo gears

Difficulty Level: Easy - Moderate

(Tools needed)

Whether you fly RC helicopters, RC planes, gliders or race RC cars, there’s a good chance at some point you’ve had a servo that’s gotten a little funky. It might have been from a crash because of excessive wear and tear or any number of other reasons.

If it’s making a clicking noise, not moving, moving a little then jamming or sounding tired, you’re in luck and can probably repair the servo yourself. In most cases, it’s a problem with the gear train and means that one or more of the gears is stripped or simply worn out.

While I’ve seen a lot of people replace servos instead of repairing them, there’s no reason to waste your money. A new servo might cost $25 to $150 when a new gear set is $5 – $10 for nylon gears or $10 – $40 for a metal gear set and it’s not that hard to do.

If your servo uses nylon (or plastic gears) one thing you might want to consider is replacing them with karbonite or metal gears which are stronger and will last longer.

While we’re on the topic of servo repair, some other things that can need repair are bent gear shafts (pins gears sit on) wires that become disconnected or bearings that have worn out. When you’re taking apart the servo to replace the gears, these are all things you’ll also want to quickly inspect. As long as it’s not the motor, amp or electronics, almost everything in a servo is user serviceable.

Step 1

(Servo arm removed)

If your servo arm is still attached, you’ll need to remove it or you won’t be able to get the cover off.

Step 2

(Tape on back of servo)

Put a small piece of tape on the back of your servo. This will hold the back cover on while you’re replacing the gears – if it comes off, it’s darn near impossible to get everything put back together correctly.

Step 3

(Screws / case removed)

Remove the 4 screws from the back of the servo and take the front cover off being careful not to disturb the order of the gears.

Note how the gears are arranged so you’ll be able to put it back together. If you don’t have a similar servo to refer to in case you get stuck, you can take a quick digital picture to use as a reference.

Also note that the main gear has a tab on it that fits into a slot on the case – it’s very important when reassembling you put the tab back in the slot.

Step 4

Remove the gears from the case and examine them. If any of them have missing teeth, make sure you fish them out of the servo or they may cause problems down the road. Clean the inside of the servo case using a paper towel or tissue.

Then pop the bearings and plastic pin off the main gear using a flathead screwdriver.

(Bearings removed)

If they’re really tight, you might need to use a little heat from a soldering iron or pencil torch, but only as a last resort – you don’t want to damage the bearings. You also don’t want to melt anything, just soften it up to break the connection.

You might also want to give the bearings a quick look to make sure they’re still running smooth and add a quick dab of grease.

Step 5

Put the pin and bearings into the new main gear and assemble the rest of the gears on the servo pins and casing.

Be careful to assemble the gears in the opposite order to which you disassembled them. Refer to your spare servo, notes or pictures if you need to.

Before putting the case back together, you’ll need to grease the gears. You can either reuse the grease from the old gears if it’s still clean, or replace it with new grease. White grease works best, but others such as TriFlow can also be used.

I used white grease in a can and just sprayed it on before putting the case back together – it’s quick and easy. You don’t want to put it on too thick, or it will just get in the way and gum things up.

Once you everything has been greased and all the pins and gears are in their respective holes, it’s time to close everything up.

Put the case together, tighten the screws finger tight and check everything to makes sure it’s working as it should.

Don’t overtighten the case screws as it can cause the gears to become jammed and don’t force the case together – when everything is together properly is should smoothly slide into place.

When everything’s done, plug it back into your receiver, turn on your radio and check to ensure everthing’s working properly. You’ll also need re-attach the servo arm in the neutral servo poistion, so now would be a good time to do so.

(Completed regearing of servo)

That’s it. The whole process might take up to 30 minutes the first time, but after you’ve done once, you can usually get the gears replaced in 10 – 15 minutes and your servo will be running like new!

For the beginner pilot hovering an RC helicopter can prove to be excessively difficult and many people give up on the hobby because they can’t master hovering.

While it is possible and people do fly RC helicopters without being able to hover properly, it’s not recommended. It’s like learning to run before you can walk and you’ll eventually run into a problem.

Being able to hover teaches control and fine motor skills that you’ll want to have to become a better overall pilot. Even top performers practice hovering to hone their skills.

There are 4 main hovering positions, or 8 if you count inverted hovering, but I’m not going to get into that as it’s a lot more complicated than learning basic, right side up hovering that we’ll discuss in this ‘how to’ article.

The 4 main hovering positions are:

As you can see from the pictures above, tail in hovering is where the tail is pointing towards you and the nose of your heli is away from you. Nose in is the opposite – where the nose of your heli is pointing towards you and the tail is pointing away from you.

Right side in is where the nose is pointing to the right, the tail is pointing to the left and you’re facing the right side of the heli. Left side is the opposite, where the nose is pointing to the left, the tail to the left and you’re facing the left side of the heli.

Preflight Setup & Checklist

Before you can learn to hover your RC helicopter, you need to make sure your heli and radio is properly setup. If unsure, consult an experienced pilot or your local hobby store.

• Put your training gear on. If you don’t have some, buy it. It costs $20 - $50 and if you’re just starting out will save you hundreds in crash damages. The training gear also makes a good visual aid that help you see the pitching and rolling of your RC helicopter before you notice them in your heli.
• If you’re flying a nitro heli, have lots of fuel available. If you’re going electric, make sure your batteries are charged and have more than one available if possible. The more you can fly continually, the faster you’ll improve your skills.
• Also, make sure your gyro is set to heading hold mode. While some people recommend flying with a gyro in rate mode because you’ll get a better feel for the helicopter, I don’t recommend it for the simple reason that unless you plan on building scale ships, you’ll probably never use rate mode, so there’s no sense learning to fly with it.
• And finally, go through your preflight check. If you don’t have a checklist you use, there’s a great printable one available here.

Getting A Feel For Your Heli

Before you learn to however, you need to understand how your helicopter works. When you move the sticks, how does your heli move? If you input right cyclic, how quickly does your heli react? The goal is to learn how your heli moves and corresponds with the inputs you give.

Once your RC heli and radio are setup, you’ll need a practice area. You’re going to want the surface you’re practicing on to be as smooth as possible so you can slide around a bit. A gym floor, a large and smooth cement basement, a ice rink or a smooth asphalt make the best practice surfaces – the smoother the better.

If you’re trying to learn on a rough or uneven surface like grass or gravel, your RC helicopter can get caught on it an tip over. The training gear will help you slide around without fear or tippage.

Make sure you have at least a 10ft x 10ft (20ft x 20ft or larger recommended) area that is clear of any and all obstructions. The larger your heli is, the more space you’ll need.

If there’s no marketing to use as a reference point, use a marker or masking tape to create one.

Put your heli into the middle of the space pointing into the wind (if outdoors) and stand 10 – 15ft behind it. Start to throttle up very slowly – you don’t want it to lift off the ground, just get it light on the training gear so you can slide it around.

If your main blades rotate clockwise and your heli’s been built properly, there’s a good chance that it will want to drift slightly to the left to counteract the tail rotor thrust pushing to the right. If your rotors spin counter clockwise, your heli should drift slightly to the right. Use the trims to compensate for the drifting until your RC helicopter stays fairly stationery.

Once you’ve got the trims set, give a little right cyclic input and watch as the heli moves to the right. Then give left cyclic input to move it back to the reference point. Then do the same thing moving your heli forwards and backwards.

The main goal here is to get a feel for how the heli responds to your stick inputs and how much input is necessary to get it to move. You’ll find small stick inputs are all that is necessary.

Once you’re comfortable with side to side and forwards / backwards movement, bring the heli back to your reference point and move it diagonally in all 4 directions. This will be a lot harder then left/right forwards/backwards movement because you’ll inputting multiple cyclic commands simultaneously as well as controlling the tail.

You’ll want to practice this until you can make very precise movements and are comfortable moving your heli around.

Remember to always fly your heli by watching its nose, never by looking at the tail boom.

Learning To Hover

All right… on to the good stuff.

Once you’ve got a feel for how your heli moves and how to control it using your radio, it’s time to get it off the ground.

For this, you’ll want to move from your smooth surface to something softer, preferable short grass. This will help to absorb any impact from hard landings and prevent damage. If you have a really small or mini RC helicopter, you can do this on the same hard surface you used earlier as there’s not much weight to cause damage.

Pick or mark a reference spot and place your heli there going through all the preflight checks mentioned earlier.

Input collective until your heli is just a few inches off the ground and try to hold it there. Remember that very small inputs make a big difference, so be gentle on the controls.

Pay attention to your heli and the balls on the training gear and try to anticipate any movement and try to compensate for it in advance. To become a masterful hoverer you need to be able to tell what’s going to happen in terms of movement and react to it in advance to prevent it from happening.

As you become more comfortable, start to bring it a little higher and higher until you get it up to 2 – 3ft and can hold it in one spot.

Congratulations!!! You can now hover an RC helicopter… everything else is downhill from here.

Though you’ll probably want to go trough at least 3 – 5 batteries or tanks of fuel practicing stationary hovering before you start to move your heli around to make sure you’ll be able to react in time in case of a mishap.

As s side note, when practicing hovering, you’ll usually want to hover above 2 – 3ft to avoid ground effect.

Ground effect is when your RC helicopter is hovered close to the ground (under one rotor diameter) and the downwash of the rotor blades creates a high pressure bubble of air. This bubble of air applies an uneven upwards force which causes the heli to wobble or move sideways making stable flight difficult. It’s a little like balancing a basketball on your finger (when it’s not spinning).

For those reasons, when practicing hovering, I prefer to hover at about 3 – 5ft. It’s high enough to avoid the ground effect and low enough that I’m looking slightly down at the heli and can use the ground as a reference.

The higher you get, the harder it is to perceive depth and keep the helicopter in one place – there’s also no easily perceivable frame of reference against the sky as there is on the ground.

However, with that being said, if you’re just starting out you might want to hover a little higher in case you make a mistake so you have time to recover. Many people use the saying “practice 2 mistakes high” meaning that you have time to recover from at least two mistakes before your heli becomes acquainted with the ground, the hard way.

Tip: Use a simulator for practicing and once you’re comfortable on your computer try it on your RC helicopter.

Once you’re able to easily hover your RC helicopter tail in, it’s time to start moving it around a little.

Repeat the same left/right forwards/backwards and diagonal movements that you did in the previous section, but this time your heli will be 2-3ft in the air and when you get to your new position, hold it there for 15-20 seconds before moving on. Transitioning from flight to hovering will help to improve your skills and take you to the next step.

Stationary side in and nose in hovering is significantly more difficult than the tail in hovering exercises mentioned in this article because cyclic commands are 90 or 180 degrees off depending on the position.

For example, when nose in hovering, if you input a right cyclic command, your heli will move to the left and vice versa, so I’ll save them for another time.

Don’t forget to check out the RC helicopter hovering tips page.

Any questions, comments, feel free to leave a comment and let me know.

Whether you’re a beginner who’s learning to fly, or an expert who wants to try out a new move, a good RC helicopter simulator is an invaluable tool to have in your arsenal.

Let’s face it, crashes in real life are expensive – and they’re discouraging

A single crash of your RC helicopter is likely to cover the cost of your average flight simulator so it only makes sense you use one. Even top ranked world RC heli champs practice on a simulator.

Simulators can save you money in other ways as well - there is also no fuel to buy, batteries to charge or fields to drive to. There’s also no weather to worry about - it doesn’t matter if it’s raining outside or there are hurricane force winds.

RC flight simulators have become a lot more popular over the last few years due to the increase in computing power and the decrease in price of fast computers.

RC helicopter simulators are computer programs which are designed to ‘simulate’ real life flying as closely as possible.

Today’s simulators boast everything from extremely realistic flight experiences, actual photographic scenery, training functions, and the abilities to create your own models and scenery.

Some simulators are so good, you can’t tell a screen shot of it from a real life picture.

While it’s not absolutely necessary - a fast computer, a good video card and a large monitor will go a long way to giving you the ultimate digital flying experience.

There are a lot of free simulators around like the FMS simulator and while they are fun to play around with, you’re not going to learn anything from them or become a better pilot.

So what makes a good simulator?

The simple answer is the one that’s the most realistic.

The most important thing you want is a flight simulator that mimics actual flight characteristics and physics or real life flight as closely as possible.

Stunning graphics or extra’s like flying lawnmowers aren’t that important if flying your simulator is nothing like flying your heli when you’re out at the field.

You want your thumbs to learn what does what and be able to carry consistency over from one to the other, otherwise it’s going to be that much harder to improve.

In fact, some simulators are so realistic, that they’re actually harder to fly than a real life heli. Figure that one out

The second most important thing you’ll want to look for is a simulator that has models available that is the same as the one you fly, or very similar to it.

You don’t want to practice on T-rex 450 when you fly a Raptor 90 – they fly nothing alike and are like apples and oranges. But you also don’t need the exact model you fly. Most quality 450 sized heli’s fly similarly and with a little tweaking, you can get the flying pretty closely to yours.

The third thing you want is a simulator that allows you to use your regular radio transmitter. It only makes sense that you learn and practice using the same equipment.

Some simulators like Realflight or Reflex have controllers available you can use for practicing and if you’re just playing around, that’s fine. But if you’re serious about improving your skills you’d ideally want to use the same controller whether you’re in front of your computer or at the field.

Another nice feature to look for is a simulator that uses real scenery – meaning a 3D panoramic image of a real life flying field. Not only is it eye pleasing, but it helps take you that bit further to simulate real flying and minimize the difference from computer to physical flight.

Some simulators like Reflex XTR will even allow you to create and add your own scenery and models which is a plus if you have a bit of spare time available.

A good site for downloading models, scenery and other simulator extras is www.rc-sim.de.

Here are some things to look for when choosing an RC helicopter simulator:

• How closely does it mimic real life flight?
• Is your RC helicopter model (or one like) it available?
• If it’s not, is it possible to create one?
• Does it have hover and other training capabilities?
• Does it allow you to control variables like wind?
• Will your computer handle it?
• How customizable is it?
• What do others have to say about it?
• Can you record your flights?
• Can you create your own scenery?

Some of the most popular RC helicopter simulators are listed below:

Reflex XTR –> www.reflex-sim.de

Pros:

• Realistic flying physics
• Uses your own radio or can buy a controller
• Has hover training
• Can create your own model / scenery
• Free updates

Cons:

• Need a faster computer than other sims
• Not a lot of model or fields are included but can be found online for free
• Expensive - $200+

RealFlight G4–> www.realflight.com

Pros:

• Can use included controller or your own radio
• Wide selection of models and flying fields
• Can download free demo
• Realistic flight and great graphics

Cons:

• Need to pay for upgrades (expansion packs)
• Expensive - $200+

Phoenix –> www.phoenix-sim.com

Pros:

• Can use your own radio
• Training tools (hover, autorotation
• Cheaper than Reflex or Realflight
• Large list of heli’s to choose from
• Model editor

Cons:

• Flight is not as realistic as Reflex or Realflight

Clearview –> www.rcflightsim.com

Pros:

• Free demo download
• Lots of heli models available
• Autopilot training modes
• Cheap - $40

Cons:

• Flight is not as realistic as Reflex or Realflight

I’d recommend Reflex or Realflight as the simulators of choice. Refelx XTR is a little more realistic than Realflight, but Realflight has a bunch of extras and training functions.

If you’re brand new to RC helicopter flying, you might want to go with Realflight, but if you’re more experienced and just looking for something to practice new moves on, then I’d recommend Reflex. Though, if you can afford it, get both.

But on the other hand, if funds are tight, you can try Clearview or Phoenix when you’re just starting. They’re still quite good, just not the best.

If you’re still not sure what to choose, many hobby stores have demos of some simulators that you can try out right in the store, so if you’re not sure what you’ll like, you can check them out in person. A lot of the websites mentioned above also have free demos you can download and try out.

While a simulator won’t replace a good instructor, teacher or mentor because they can help you with your setup, buddy box with you and offer customized advice, but they will go a long way to improving your flying abilities and confidence at the field.

When you think about it, there’s not really any reason not to get an RC helicopter flight simulator – it will pay for itself many times over and enable you to become a better all round RC helicopter pilot.

I picked up one of these a few months back and love it. Though, as far as battery chargers go, it’s not cheap coming in at just under $300 by the time you add taxes and shipping (it retails for $269.95).

The Hyperion Duo is a 360 watt, dual port, balancing charger that can pretty much charge almost anything you can throw at it including:

• 1-6 Cells Lithium Polymer
• 1-6 Cells Lithium Ion
• 1-6 Cells A123
• 1-16 Cells Nicd/Nimh
• 1-12 Lead Acid

Because of its dual port design, it can charge two battery packs simultaneously whether you network them together and charge / balance them as a single pack (ex. charge 2 x 5s lipo packs as a 10s), or if you charge two unrelated batteries such as a NiCd and a LiPo pack at the same time.

This is one of the reasons I’m such a fan of this charger – the amount of time it saves by being able to charge 2 batteries at the same time, even if they’re completely unrelated is astronomical.

One of the main heli’s I fly runs off a 10s power system (2 x 5s) which I used to charge and balance with an Astro Flight 109 and a Thunder power TP210 balancer. With that setup, the total charging and balancing time was about 5 hours, but with the Hyperion Duo, it only takes about 70 minutes, keeping downtime to a minimum and allowing you to get back in the air that much sooner.

And with a total output power of 360 watts or 180 watts per channel, you can change two 6s packs at up to 8A each. The Duo can charge batteries at 0.1A – 10A or anything in between in 0.1A increments.

The charger also features an integrated balancer with 300mA of balance power per cell, and with the variety of balance adapters made available by Hyperion, you can balance almost any pack imaginable.

(Balance adapters for various LiPo packs.)

Another great feature which isn’t seen on a lot of other chargers it that it can run off an input voltage of 11 – 18 volts. There are a couple benefits of this:

1. It’s compatible with a wide range of power supplies across many different output voltages and amperage ratings.
2. It’s more efficient when charging higher voltage packs.

It’s also very easy to use. Without the manual (it wasn’t included in he box - apparently they weren’t able to get it printed in time to include it with the chargers, but they did provide a link to a downloadable manual.) it took about 2 minutes to figure out how to use it.

The Duo’s menu is well laid out and simple to use and allows for selectability between output channels and all of the charging specifications. Each output channel features 10 memory positions that you can set depending on the batteries you are charging.

Some of its other features include a 2 line blue backlit display which is easy to read in daylight or the dark, user defined alarms, reverse polarity protection, dual cooling fans and a PC data port to upgrade firmware.

Using the menu, you can display all kinds of info about your batteries on the screen including the mAh you put into back the pack, the voltage per cell, the battery temperature, charging time and so on.

You can also set things like how many amps you want your packs to charge at, the total charge capacity of the battery as a percent and a safety timer which turns the charge off after a predetermined amount of time.

It even has alligator clips that can easily be fitted on the bullet connectors to charge off your car or other battery.

Hyperion also has optional temperature monitors than can be used to monitor packs while charging and shut down the charger if the pack gets too hot. The shutdown temperature is user selectable.

While the Hyperion DUO is a great charger, it’s not perfect…

It doesn’t have a built in pack discharger and in a high end charger of this calliper, a discharger for cycling packs is pretty much a standard feature. I don’t know if it was too expensive or complicated to add, but you’d think that Hyperion would lose a lot of sales because it’s missing. If you want something that will discharge or cycle your packs, you pretty much need to keep a second battery charger around.

Tip: While the DUO won’t discharge your LiPo packs, it has a “Store Mode” feature that will slowly discharge the cells (using the balancer) down to a 3.9V per cell storage voltage if your packs won’t be used for a week or more.

The other downside of this charger it that it can only charge up to 6s LiPo packs. With the higher power 10s and 12s setups favoured by some electric RC helicopter pilots (myself included), you can’t charge the higher voltage batteries with this charger.

You can charge 2 x 5s or 2 x 6s packs to make a 10s or a 12s pack, but you can’t charge a single battery pack above 6s.

While I can honestly say that purchasing this charger is one of the best RC helicopter investments I’ve made, I’m a little disappointed by its two limitations that prevent it from being a true ‘all in one’ RC battery charger.

Why would you want to calculate the head speed of your RC helicopter when you can simply measure it using a tachometer?

Believe it or not, there are a couple of reasons, the most obvious being that you might not own a tachometer.

But the more common reason you’d want to be able to calculate the head speed of your RC helicopter is before you buy it.

When you’re purchasing a new bird, you traditionally need to match the motor pinion with the head speed you’d like to achieve and since you can’t physically measure it, you need to calculate it.

Calculating the head speed using the formula below won’t give you an exact head speed, but it will be close enough to tell you which pinion you should use to get the head speed you want.

Variables like air temperature, humidity, altitude, wind and more will affect the actual measured head speed of your RC helicopter, and although using complicated mathematical algorithms you can compensate for them, there’s not really any reason to be that accurate.

Anyways, here’s the formula:

Head Speed =

((Motor Kv x Battery Voltage) / (Main Gear Teeth / Pinion Teeth)) x Efficiency Coefficient

The Kv of your motor equals the RPM (rounds per minute) it turns per volt applied.

For example, if your motor turns 812 RPM per volt it would have a Kv of 812. When running it on a 10s or a 37v setup, the motor would be turning at 30,044 RPM.

But since electric motors aren’t 100% efficient and some energy is lost to friction and heat, we multiply the RPM by the efficiency coefficient of the motor to get the actual RPM.

Most brushless motors have an efficiency rate of about 87% – 92% and a motor turning at 30,044 RPM with an efficiency coefficient of 89%, would really only be running at 26,739 RPM (30,044 RPM x 0.89 Efficiency Coefficient = Actual RPM of 26,739).

The battery voltage is the nominal voltage of the pack. Even though a 37v pack will be around 42v when fully charged, it runs at around 37v under load so that’s the number you’ll use for head speed calculations, not the fully charged / discharged voltage.

The teeth on your main gear and pinion is simply the number of teeth on the gears. Most manufacturers publish that info, but if in doubt, count it out.

By the way, this only really works with electric helicopters. There are ways to estimate the head speed of a nitro or gas powered RC helicopter, but it gets to be much more complicated and isn’t really as necessary as it is with electrics.

Here’s a quick example:

Head Speed = ((812 Kv x 37v ) / (140 teeth / 10 teeth)) x 0.89 efficiency coefficient

Head Speed = (30,044 / 14) x 0.89

Head Speed = 2,146 x 0.89

Head Speed = 1,910 RPM

The actual measured head speed of my heli using the above calculations was 1920 - only 10 RPM off from the calculations.

(Draganflyer V Ti Pro)

Go Back To Part 1 Of The Review

Draganflyer Preflight Checklist

• Make sure all batteries are fully charged.
• If you’re using them, make sure the heat sinks on the motors properly and the air vents aren’t covered.
• Gently pull / twist the carbon fiber rods. If they pop out of the mounting brackets tighten the screws. By twisting them, you’ll also be able to see any hairline fractures that could cause potential flight problems.
• Check to make sure the rotors / motors are on straight and alighted properly and that they’re on securely - if one moves a little during flight, it can throw off your trims significantly.
• If you’re using the video camera option, make sure the mount and camera is secure and that the screws aren’t loose.
• Check to ensure the circuit board is in the braces securely.
• Also quickly check all the screws to make sure they’re tight including the nylon screws on the rotors and under the Draganflyer on the base plate.
• Make sure the transmitter is on and the throttle is all the way down and set all trim levels to the center, then set the thermal intelligence if you’re using it, place the Draganflyer on level ground and you’re good to go.

Learning To Fly / Flying The Draganflyer

Before you attempt to fly the Draganflyer, as with any RC helicopter, read the instruction manual in fullness and watch the instruction DVD. Also take a few minutes to familiarize yourself with the radio transmitter and actual mechanics of the Draganflyer.

If your unit came with the onboard camera, it would also be a good idea to remove it to prevent damage while you get the hang of flying the Draganflyer.

You should start by learning to hover it. I’d do it indoors with the thermal intelligence off for two reasons.

1. There’s no wind to worry about.

2. Learning with the thermal intelligence off will make you a better pilot. By the time you take it outside and turn the Ti on, you’ll be an expert.

I learned to fly it indoors without the thermal intelligence and once I brought it outside and turned the thermal intelligence on, flying it was a piece of cake.

Start with moving it around on the ground (preferably a smooth surface) to get a feel for it.

If the Draganflyer is flying off-level, you can use the trims on the transmitter to correct for it. Even a little weight imbalance, a slightly misaligned rotor or the performance of each individual motor can cause imbalances, so setting the trims to adjust for it is necessary. You may need to adjust them significantly to get level flight.

When you’re using thermal intelligence later, the trims will still need to be adjusted, but not by as much. If you set it on level ground and set it before flight, it should fly more or less level.

Once you get the hang of how it works, slowly bring it an inch or so off the ground and try to hold it within a 3ft by 3ft area.

When you’re good enough to keep it in a 3ft by 3ft area, bring it up to 12 inches and keep it in the same space, then graduate to 2ft off the ground, 3ft and so on.

When you’re able to hold it in a hover about 3ft off the ground, practice moving sideways about 5ft, then stopping and holding it in a hover. Do this in both directions (left / right).

Once you master that move, try flying a figure 8, circles and a 4 point square indoors before you take it outside.

For more advanced moves, try hovering it with the front facing you (backwards), landing on a box or ledge, flying around an obstacle course (trees, playground – power lines not recommended).

You can practice your moves on the free FMS Flight simulator where both the standard Draganflyer as well as the $5,000 X-Pro Model are available as free downloads.

You can control the simulator with your keyboard or for about $25 from Draganfly Innovations, or $10 from many other online retailers, you control it with your Futaba transmitter.

As of current, the simulator doesn’t work with Windows Vista, so keep a copy of XP around if you plan on using it.

With the thermal intelligence turned off, it took less than 5 minutes to get it trimmed up and hovering in my basement, but I did have a little RC heli experience :). In about 3 batteries, I had it flying around the place quite easily.

I also let my younger brother (with zero RC helicopter experience) give it a try, and after a little coaching from me, he had the hang of it in about an hour. In another hour, he was zipping around the local soccer field.

It’s not hard to learn on and if you can find someone locally with experience flying it and practice on the simulator, the learning curve will shorten significantly.

Flying the Draganflyer is quite easy when compared to a normal RC helicopter. The hardest part of flying it was keeping track of which side was the front, so I took some fluorescent pink tape and wrapped it around the front of the frame bracing.

Flightlog / Maintenance

If you hear any funny sounds when flying (high pitched whirring, clicking or grinding) land immediately to diagnose the problem - it’s not going to go away on it’s own and will only get worse. Same thing does for smoking motors or circuit boards.

If you can’t tell what rotor is the source of the problem, hold the Draganflyer firmly in your hand, turn it on and move the control stick left, right, up and down until you hear which rotor is causing the problem.

The work best with smooth edges. If they get roughened up from use or hitting something, you can smooth them out with a piece of fine sandpaper.

The motors are brushed and will wear out. Throughout the 50 of so flights I put on my Draganflyer, I ended up replacing all of them. Adding the optional heat sinks can help extend their life somewhat.

Replacing them requires a soldering iron and some very basic soldering skills to remove the lead wires and solder them to the new motor. It’s so really important that you solder the wires on correctly - the front and rear motors spin clockwise, and the left and right motors spin counter-clockwise.

The Draganflyer I received had a gyro that went bad after the first couple of flights. After a little negotiating, the people at rctoys.com sent me a new one free of charge when I convinced them I could replace it myself and didn’t need to send the heli back..

One other problem I experienced was a glitch that popped up now and again causing you to temporarily loose control of the heli.

I had this happen to me 3 times in about 50 flights, once resulting in a hard crash where I wasn’t able to recover in time.

I don’t know if it’s a design flaw or something else, but from what I’ve seen on discussion forums, I’m not the only one to experience it.

Update: According to the rctoys.com website, it was a receiver issue and has been remedied, though I haven’t tested the updated model. It’s just something to take into consideration if buying used… and luckily repairs are fairly cheap.

Anyways, maintenance is pretty simple, nothing more that giving it a good look over to check for broken parts, loose screws and keeping it clean. With the glitch crash, a run in with a tree a few other hard ladings, over about 50 flights, I purchased about $150 in replacement parts including a couple of new canopies for paining. That’s not too bad, considering a single crash on a single rotor heli could easily be double that.

Customizing The Draganflyer

There’s not much that can be done to upgrade or customize the Draganflyer which was a bit of a disappointment.

Rctoys.com doesn’t really offer anything in the way of upgrades, except for video options, the frame bracing, larger capacity batteries and motor heat sinks.

There was a guy making carbon fiber rotor blades for the Draganflyer that was selling them online for a while for about $100 a set, but he seems to have disappeared along with another dude from Australia selling landing gear to protect the motors (pictured above).

To customize my Draganflyer a little, I painted the canopy a flat back (on the inside of the clear dome) and replaced the green LED’s for blue ones which looked awesome.

(Customized Draganflyer with black canopy, blue LED’s & landing gear)

Blue LED’s run off about 5 volts while the standard green ones run off 3 volts, so I had to add a standard NPN transistor (available at radio shack) to the circuit board for each LED to up the voltage. There’s a 5 volt source available from the pins at the front of the circuit board (on each side) which I used to power the LED’s

I wouldn’t recommend changing the LED’s out unless you have some electronics / soldering experience and modifying the circuit board will void the warranty.

Some other people have also upgraded the entire heli to a brushless system that about doubles the lifting capacity, power and increases flight times. You can find out more on the brushless conversion here: http://www.rcuniverse.com/forum/m_6195100/tm.htm

How To Save $200 - $300 on a new Draganflyer

Even though Draganfly Innovations sells the base model Draganflyer on their website (www.rctoys.com) for $799, they consistently sell them on eBay where I’ve seen them go for as low as $500 with an average selling price around the $600 mark.

They claim they sell them at a loss that’s made up for in publicity, advertising and the cost of replacement parts. They also sell a refurbished unit that works like new for about $100 less on their website or on eBay.

Conclusion

For the first few months, I thought “this is fun” but was soon thinking “what else can I do with it?”

Even though I used it to shoot a few videos, aerial videography is nothing that I do for anything other than fun.

As far as entertainment value, I got a lot out of it in the first few months, but it’s quite limited in what you can do aerobatically. It’s not like a fully 3D RC helicopter where there’s always a new move you can learn or something else you can try. There are only so many ways to fly it and so many things you can do with it before you run out of options.

However, it’s great at what it was designed for - it’s an excellent tool for quality aerial footage at an affordable price.

Should you buy a Draganflyer?

I can’t really answer that, but if you’re looking to learn to fly a simple RC helicopter or have a need to quality aerial footage, then it would likely make a good investment.

Price As Tested: $1,499

Flight Log: ~ 50 Flights

Repair / Maintenance Costs: ~ $150

Skip To Part 2 Of The Review

The Draganflyer is a RC helicopter with a bit of a twist. Instead of a single main rotor, or even coaxial / dual rotors, it has four of them - two spinning clockwise and two spinning counterclockwise.

(Draganflyer SAVS)

It’s manufactured by Draganfly Innovations Inc. and sold at www.rctoys.com as well as many other websites from eBay to Amazon.

If you’re in need of an affordable aerial video solution at a low price or just want something to fly around your backyard, the Draganflyer fit’s the bill perfectly.

In fact, this little heli has become so popular, it’s been featured on the Discovery Channel and in magazines like Popular Science.

With a diameter of just 30 inches, this little heli packs quite a punch.

The Draganflyer was developed as a simple and cheaper alternative to obtaining quality aerial video, which until recently, required renting a full sized helicopter or airplane.

The Draganflyer’s self leveling feature and anti-vibration camera system produces high quality video which makes it a viable alternative to a full sized helicopter.

It can be used for things like surveying, surveillance, small budget video production, real estate marketing, farmers field quality control or inspections of hard to reach or dangerous locations.

The Draganflyer is primarily made out of carbon fiber, high-impact nylon, and plastic and is designed so that the plastic parts take the brunt of most crashed.

Draganfly Innovations designed it this way on purpose… “The parts will remain plastic as if they did not take the impact, the carbon frame would, resulting in much more downtime in repairs as the entire harness would need to be removed.”

Most repairs can be done in about 10 – 15 minutes, but if you start breaking the carbon fiber control arms, you’ll need to get out your soldering iron and spend a little more time threading the wires through the control arms and re-soldering them to the motors.

It is quite durable during a crash, mostly due to its light weight of just under 500 grams (Approx. 1lb).

To help keep weight to a minimum and flight times to a maximum, the Draganflyer runs of Lithium Polymer batteries that allow for about 15 minutes of flight time.

But because of its light weight, its relatively large footprint makes it quite susceptible to wind gusts. Even through Draganfly Innovations claims it can be flown in 20 mph winds, I wouldn’t recommend flying it in anything above 10 or 15mph unless you’re an experienced and skilled pilot.

The standard Draganflyer V Ti package comes with everything you need to get started including the complete Draganflyer (frame, circuit board, rotors, canopy), battery, charger, transmitter,

The V Ti Pro model comes with everything the base model does with the addition of a 6 channel computerized radio, frame bracing as well as a micro wireless video camera with transmitter, receiver and camera mount.

The SAVS model comes with an upgraded video camera and transmitter, video enhancing circuitry with regulated camera power supplies, video filters and high gain video transmitter antenna as well as a vibration free camera mount, 2.4GHz Diversity video receiver with adjustable positions, two, circular polarized, 8 dbi patch antennas and a hard carry case.

You can see the differences between the available models here.

The Draganflyer’s Stabilization

The Draganflyer is very easy to fly when compared to a conventional RC helicopter and extremely stable thanks to the 3 axis gyro stabilization and thermal intelligence.

The unit used three piezo-electric gyros which aid in stabilization for roll, pitch and yaw as well as a patented thermal intelligence system which makes it a very stable platform for shooting quality video from the sky.

(Closeup of the Draganflyers cirucit board showing gyros and Ti sensors)

According to rctoys.com the “Thermal Intelligence uses patented technology to sense the difference in infrared temperature between the Earth and sky… …Ti uses four infrared sensors, so when a change is detected in the Draganflyer’s orientation relative to the Earth’s infrared horizon, it issues the correct control signals to bring the Draganflyer back to level flight.”

The thermal intelligence needs to be set before each flight while holding the Draganflyer vertically (two sensors pointing at the sky and two at the ground) at arms length and pushing a small ‘arming’ button next to the main power switch. This helps the Draganflyer see the differences in the infrared heat signatures between the ground and sky allowing it to make corrections and keep the unit level.

After setting the Ti, you’ll also need to show the heli what ‘level’ is. This is done by sitting it on a flat / level surface and holding the left throttle stick all the way down and to the right until the two green LED’s flash meaning the level position is stored.

If you don’t get it on perfectly level ground, it will tend to drift to one side and you’ll need to correct the trims on your transmitter.

Once the thermal intelligence is set, the Draganflyer’s CPU automatically returns the helicopter to level when the control stick is released. This feature makes it easy to fly, and professional quality aerial video not that far off for the amateur.

Video Capabilities

If you need to get close to the action, or can’t afford to hire a full sized helicopter / videography, V Ti Pro or SAVS (Stabilized Aerial Video System) allows you get in close to the action and still capture high quality video.

It doesn’t do High definition (HD) video, but with some modifications, a lot of upgrades and some customization, it could be converted for a price.

The SAVS high quality video is possible because of the anti-vibration video camera mount that isolates the camera from vibrations.

The video stabilization system relies on a series of rubber bands which is a bit crude, but effective. Also, because it’s electric, vibration levels are at a minimum.

The onboard wireless 2.4GHz CCD camera transmits live video to a ground base station, and uses advanced circuitry featuring several filters and independent regulated power supplies to preserve the clarity of the video signal. The SAVS base station features a diversity video (dual antenna) receiver which selects the best signal in real time.

A video recorder isn’t included, but any handheld digital video recorder or camcorder will work fine.

What Else Should You Get

While the Draganflyer comes with everything you need to fly, it doesn’t come with any extra spare parts, so I’d recommend picking up a crash kit or two – no matter how good you are, you’ll inevitably crash and will need some extra parts.

I’d also get an extra battery or two. Even though some people claim flight times of 20 – 30 minutes, unless you’re flying extremely mildly, you could expect a realistic flight time of about 15 minutes. Charging time is only an hour or so, but when you’re out at the field, you won’t want to have to wait. More batteries mean more fun before you have to recharge.

If you’re buying the base model, you might also want to upgrade to the 6 channel Futaba computer radio. It’s more customizable than the one shipped with the unit and has digital trims vs. manual trims that it save in memory. The option is not offered on their website, but a quick email and about $70 and it can be yours.

You might also want to pick up a few extra fuses. If you land in tall grass (or crash) the extra strain / resistance put on the motors can cause it to blow.

Another thing you might want to consider more as preventative therapy for your motors are the optional motor heat sinks. As I mentioned earlier, I had to replace all of my motors within the first 50 flights… had I bought the heat sinks right off the bat, I suspect their lifetimes would have been significantly longer.

And one last option you to consider is getting the thumb screw set. The main rotors screws need to be tightened often and the thumbscrews make it painless and easy task.

Tools You’ll Need

In addition to a crash kit and some of the extra’s mentioned above, you’ll need a flat head screwdriver, a hex driver and a small pair of needle nose pliers.

If you ever need to remove / replace the motor or take them off to replace a broken part (and you will) you’ll also need wire cutters / strippers, a soldering iron and solder.

Having a roll of black electrical tape and light sandpaper around will also be helpful for loose or tight fitting parts. The sandpaper can also be used to smooth off the burs found on the rotors which will slightly improve performance and noise.

Luckily, chances of plummeting to the ground like an rock are slim. Thanks to the art of an autorotation, a skilled pilot can safely glide their helicopter in for a smooth landing.

An autorotation is simply the ability of a helicopter to land safely without engine power by using the stored rotational energy in the rotor blades to product lift just before landing.

During an autrotation the helicopter pilot manupilates the pitch of the rotors to take advantage of the airspeed provided by the helicopters decent, to sustain operational RPM. Just before landing, the pilot ‘flares’ producing momentary lift and landing safely.

What that means in English is that when a helicopter looses power and starts falling back towards earch, the pilot changes the pitch of the main rotors so the air rushing through them will speed them up.

Think of it like the wind turning a wind turbine, but in this case, the airspeed generated from the downward decent turns the rotors of the helicopter allowing the pillot to maintain a fast enough rotor RPM to provide lift and allow for a safe landing.

Here’s a more detailed explanation of how an autorotation works:

How An Autorotation Works

The principals of how an autorotation work are pretty simple. You simply swap potential energy (height of heli) for kinetic energy (speed of rotors).

The rotational force and angle of attack of your rotor blades provide lift at a positive pitch angle.

During an autorotation, the rotors are moved to a negative pitch angle to build up speed (kinetic energy) and keep them spinning in a forward direction as your RC helicopter decends.

As your helicopter gets near the ground, you quickly change the pitch angle from negative to positive (flaring) and the kinetic energy built up in the rotors provides enough lift to glide it softly to the ground.

The key to a successful autorotation is flaring (changing pitch from negative to positive) at the just right time.

Since the flare uses the last of the remaining kinetic energy in the rotors, it needs to be timed perfectly. If you flare too late, your heli will hit the ground hard and if you flare too early, your RC helicopter will run out of kinetic energy and plunge the rest of the way to the ground.

During a controlled autorotation, you’ll ideally want some forward airspeed when practicing your autos – it provides for a clean air path and will help generate more rotor RPM and a slower decent.

What You Need To Auto – RC Helicopter Specs

You need two things (besides pilot experience & skill) to perform an autorotation on your RC helicopter..

The first is that you need collective control of your heli, so cheaper fixed pitch RC helicopters can’t do an autorotation. In the event of a power loss, their rotors will stop spinning fairly quickly and the heli will fall to the ground like a rock.

For that reason, many small mini or micro electric RC helicopters can’t perform an autorotation, but then there’s no real need for them to have to.

With a well kept electric heli, it’s extremely unlikely that you’d ever need to perform an autorotation, because unlike a nitro or gas RC helicopter, the motor won’t quit all of a sudden. The batteries will slowly loose power and the rotors will slowly stop spinning, giving you ample time to land safely - even with lipo batteries.

The second thing your need to perform an autorotation is way to allow the main rotor shaft to spin freely from the rest of the gearing / motor or drive assembly.

This is accomplished by a one way beating on the rotor shaft – if the motor clunks out or locks up, it doesn’t matter because the one way bearing will allow the main shaft and rotors to continue to spin and build up speed during an autorotation.

Some RC helicopters also have a driven tail during an autorotation, meaning that the gearing is set so the tail will continue to spin during an auto allowing you to maintain tail control.

The downside to a driven tail is that is uses up energy that would otherwise go to spinning the main rotors faster, and the faster the main rotors are spinning, the easier the auto is to land.

And driven tails aren’t really necessary during an autorotation because there is no rotational torque to counteract, but if you need to get the heli turned around to a better orientation, it can be nice to have.

Even though you may never need to perform an autorotation because your engine quits or your batteries crap out, it’s an extremely important skill to have in your arsenal for that one time you might need it.

If you have access to a simulator, it’s always best to practice on it first before taking it out to the field. If you don’t get the timing just right, a hard landing could result in a boom strike or total annihilation.

Happy flying!