Have you ever wanted to mod your RC airplanes, perhaps to carry an explosive payload? Too bad – it’s illegal. Don’t worry though, here at Draganfly Innovations, we’ve found the next best thing: you can mod inexpensive RC planes to carry containers of inert powder, which will shatter and make a super nifty effect on the ground. All you need are 5 minutes and some common household materials:

What You Need

• Toothpick – We’ll use this to make a mount for the payload, and a mechanism that lets us deploy it remotely.
• Plastic Easter Egg (or similar container) – Plastic Easter eggs work best, because they split in two easily. You can find them at almost every craft store. Improvising here is fine, just make sure that your container is a reasonable size, and will open up with minimal force.
• Cellophane Tape – This mod isn’t permanent, just peel off the tape when your done with it.
• Plastic Drinking Straw
  
• Vortex Extreme RC Airplane – You can get one on our website. Similar models will also work, but if they’re of a different design, you’ll have to adapt these instructions accordingly.
• Talcum Powder, Flour, or any (safe) Powdery Substance – Basically, anything that spreads out in the air and makes a big cloud will do.

How to Mod Your RC Airplanes

1. Start by taking the wing off your RC airplane. You need it out of the way, because your going to be building the drop mechanism on the bottom of the plane. Besides, breaking foam wings is no fun – store it in a safe place until your finished these steps.
2. Cut about a 1 inch length of straw, and tape it to the tail boom, 2 inches back. You want to get the straw aligned parallel to the tail boom, and hanging right on the bottom. What we’re trying to do won’t work if the payload rubs against the tail and gets stuck. You might want to click this picture, to get a closer view.
3. 

   Tape the toothpick to the round end of the plastic egg. The aim is to give the toothpick an upward slant, so that the egg hangs on to your RC airplane under gravity.Try to leave as much of the toothpick as possible free – this gives you a more secure mount. It’s very important not to tape the Easter egg shut, because the whole point is to get it to split open on ground impact.

4. Fill the Easter egg with powder, and then snap it shut.
5. Slide the “bomb” onto your drinking straw launcher apparatus (see the picture on the right), and get the plane ready for flight.

Dropping the Bomb

The Easter egg you mounted is held on the airplane by gravity and wind resistance. To drop it, simply take off as usual, fly to a safe area (free of people, pets, and vehicles), and put your RC airplane in a nose dive. The “bomb” should slide off the mount, hit the ground, and produce a nice puff of smoke. Watch Out: many RC planes have crashed because the pilot was looking at the payload being dropped, and not paying attention to flying. Let spectators enjoy the bomb, and concentrate on landing your plane safely.

Here’s what the result of a properly detonated “bomb” looks like (the best explosion occurs at about 1:12 into the video):

Need RC airplanes for this project? Get a Vortex Extreme online. Perfect for beginners to learn how to fly, and affordable, it makes the ideal first RC airplane.

ROAR (Remotely Operated Auto Racers) is a national non-profit organization dedicated to promoting rc cars and trucks. ROAR also provides liability and bodily injury insurance for it’s members who race at ROAR sanctioned events and keeps a database of approved lithium polymer batteries. Tested at ROAR’s laboratory, approved lithium polymer batteries need to meet criteria including safety and performance. If you’re racing your electric car or truck at a ROAR sanctioned event, you should use approved batteries. We carry all of ROAR’s approved Thunder Power RC batteries, listed below:

You can browse through our huge selection of Thunder Power RC lipo batteries on our site. We pride ourselves on carrying every battery that Thunder Power RC manufactures, so if you see one that we’ve missed, feel free to contact us.

All RC airplanes and helicopters are controlled by servos - small, electromechanical devices that allow everything from controlled flight to payload releases. So what are servos?  How do they work? And how do you choose the ones that will work best in your model? We’ll answer all these questions, and take you through everything from the basics of servo operation to their technical details.

What is a Servo?

A servo is a device that can rotate to an arbitrary position, as set by the user. Servos usually consist of a small DC (direct current) electric motor, several gears, and a head where an arm or wheel can be attached. When the user tells the servo what angular position to move to, the servo rotates and holds that position until further input is specified. The servo holds position because external forces are always interacting with the aircraft, and would set control surfaces to undesired positions unless stopped. Servos exert a torque on external forces, that prevents them from changing the position of any control surface.

How Servos Work

A servos job is to convert the angular movement of a servo arm to the linear movement of a control surface. This is done by attaching linkages, called control rods to the servo arm and the associated control surface. When the servo head rotates, it pushes the control rod back and forth. The rod is linked to a control surface, and can move it up or down as the servo rotates.
Servos are controlled by three wires: two to provide the DC power that the motor needs, and one that sends the signal, controlling the servo. The signal wire works by sending the servo a series of pulses, which are interpreted by its internal circuitry. By varying the timing of each pulse, the servo knows exactly which position to move to.

RC Servo Motors

The motors that drive RC servos come in several different types. Here’s a list of the most common varieties, and some information on each to help you decide which ones to use:

• Coreless – Conventional motors use copper wires wrapped around metal cores to form electromagnets. In a coreless motor, there is a metal mesh that rotates around the permanent magnets. Coreless motors respond more quickly than conventional motors, because they don’t have to overcome the momentum associated with heavy metal cores.
• Brushless – Servos can be powered by brushless motors, giving them longer life, faster response time, and more torque.
• 3 Pole and 5 Pole – Electric motors have permanent magnets, called poles, that electromagnets are attracted to. Servo motors can have either 3 or 5 poles, with more poles providing better torque. If you’re new to RC or have a regular sport model, you probably won’t notice the difference between 3 pole and 5 pole servos.

Choosing the Right Servo

Servos have a number of defining properties that make them suitable for different applications:

• Torque – This is a measure of the servos strength, or how much “push” it has. More precisely, torque is the product of force and the radius at which it acts. This is shown graphically in the figure on the right. Bigger planes need high torque servos to move their large control surfaces. In general, servo size goes up with rated torque.
• Dimensions – Servos come in many different sizes, which you can choose from depending on your application.
• Weight – The weight of a servo depends on several variables. Most often recorded in grams, the weight of a servo is always reported on the package.
• Bearings – There are two ways to support the output shaft of a servo – bearings and brushes. Brushes are cheaper, but bearings last longer and operate more smoothly. Very small and very cheap servos tend to be brushed, while high end and very large servos generally have bearings. It’s possible to upgrade a brushed servo to bearings, with several upgrade kits being available on the internet.
• Gears – Most hobby grade servos use nylon gears, while higher end servos use metal gears. Metal gears add more weight, but their advantage is that they can’t “strip”, causing an RC helicopter or airplane to crash. Metal gears wear over time, which can cause “slop” in their rotation, but the gears can be replaced somewhat economically. In general, nylon servos are adequate for sport flying. If you’re particularly worried about losing a model in a crash, or are flying intense aerobatics, a metal geared servo is probably the right choice.
• Speed – Speed measures how fast the servo can move from one position to another. Different RC airplanes and helicopters will need servos with different speeds. For example: a trainer doesn’t need to change control surface positions rapidly, but a 3D helicopter or plane does. High speed servos are many times more expensive than standard ones.
• Digital / Standard – Servos can be of two types: digital, or standard. Both digital and standard servos can be used with a normal receiver, the real difference is performance. All servos use a series of short pulses as signals that determine what angular position they should maintain. This series of signals is usually very fast, somewhere around 50 pulses per second maximum. On a standard servo, this rate is so fast that small movements of the control sticks may not have an affect. This means that there’s a small deadband on the control sticks, in which no servo movement takes place. Although it’s not a problem on trainers and most sport class models, the deadband becomes a significant issue with 3D aircraft. Even a small delay with a 3D aircraft could cause a crash.
  Digital servos remove the deadband by speeding up the rate at which it receives      pulses. Usually, this is increased from around 50 to 300 pulses per second. This increase in resolution allows the servo to operate much more precisely.

All RC kits and ARFs will specify the type and brand of servo required. Generally, you should adhere to these recommendations.

Now that you know what servos to get for your model, you can browse the large number of servos available on our website.

You can use any model aircraft equipped with a camera to measure distances on the ground. This is great for hobbyists interested in making their own maps, or if you’re just curious what the distance between two far apart objects is. With a little trigonometry (a gasp is heard throughout the room), all you need is to measure one angle and one distance. I’ll walk you through the math, it’s not actually that hard, and the end result is more than worth it.

What You Need

To do this project, you’re going to need a few materials:

• An RC helicopter, or RC airplane with 3 channel control or better – You’re going to need a stable platform to take pictures from. Helicopters are useful because you can hover in one position, but airplanes are cheaper. You might already have an airplane or helicopter around, but if you don’t, the Multiplex Easystar works well for this project. Note that to make a remote shutter function, more than 3 channels are needed.
• A lightweight camera, with remote shutter operation – You need to be able to remotely trigger the camera. This can be done a number of ways, but the simplest and most economical is to attach a servo to the top of your camera with rubber bands. Make it so that when you throw a spare channel switch on your transmitter, the servo arm will move and press down the shutter switch. As with any mod, feel free to create your own solution.
• A large protractor
• Some string and a weight – Clay works well as a weight, I’ll explain why you need it shortly.
• A drinking straw – You’re going to need this to build a sight for the protractor.
• Measuring Tape – You need to know the altitude of your aircraft, and to do this, you need to measure it’s distance from you. Landmarks with a known distance can also be used – consult any street map with a scale for these.
• A notebook / paper / pencil
• A friend to help – You can’t fly your aircraft and make measurements at the same time. Take a friend along to help you, and ask them to record the measurements.

The Math Involved

Now we come to the hard part – a little bit of math. You don’t really need to understand all these derivations, feel free to simply use the formula that I’ll give you. The problem is this: given an aerial picture, how can we figure out the scale?

We need the altitude of the airplane to figure out the image scale. This can’t be done directly, so we measure the angle (a), the distance (d), and use them to compute the height (h). This is a right triangle, and there are some handy trig functions that apply. In this case, we use the tangent function, which gives the ratio of the opposite and adjacent sides.  This is expressed as follows:

By taking the tangent of the angle a, and multiplying by the distance (d), we get the height (h). Here’s the formula that you would use:

So how do you get the angle? It’s simple: take the protractor and tape a piece of drinking straw to the flat bottom. Then attach a piece of sting to the bottom center of the protractor, so that it dangles straight down the 90 degree mark. Use the ball of clay to make a weight at the bottom of the string. Now, when you tilt the  protractor, the string will measure the angle. Be careful though: the angle with respect to the ground is not what’s read directly off the protractor scale. Reading the difference between the indicated angle and 90 degrees will give you the angle you need.

So why do we care about the altitude? Well, it turns out that the ratio of the altitude and the focal length of the camera is the image scale! You can find out the focal length of your camera by reading it’s manual. This is usually expressed in millimetres, so convert it to whatever  unit you have used to measured the distance, and thus the altitude in. Let’s put that all in a convenient formula:

And that’s the only formula you need. Just measure the distance, and the angle, know the focal length, and you’re done.

How to Do the Measurements

All that math was fun, but how do you actually measure distances using this method? I’ll illustrate with an example:

Suppose that you’ve just gone out to a field, and want to measure the distance between a tree and a building. The first step is to find a landmark you can fly over with a known distance. Using a measuring tape or map, you find that a nearby hill is 50 feet from where you’re standing. With a friend ready to measure and write down the angle, you launch your airplane and fly over the nearby hill, taking several pictures. Your friend sights the model aircraft through the protractor – straw device built earlier, and finds the angle to be 75 degrees.

Using a calculator, you find the altitude to be:

After landing, you download the pictures and print them full size, with no scaling. Your camera’s user manual reports that the focal length is 152 mm (millimeters). Converting this to feet is easy, just type it in Google or multiply by the number of feet per millimetre. 152 mm is 0.48 feet, so you plug that into the formula we derived earlier and obtain the following:

This means that distance measured on the picture is 0.000257 times as big as the real distance. You’re almost done: using a ruler, you measure the distance between the tree and building on the image to be 1 inch. Converting this to feet (because we want the distance between the building and tree in feet), gives a distance of 0.0833 feet. Now, multiplying this by 1 divided by the picture scale gives a final answer of 324 feet.

And that’s it – you’ve just measured the distance between two objects using nothing more than a RC aircraft, camera, and a little trigonometry. Just keep in mind that you have to know the distance between the airplane and you accurately for this to work – always take pictures right on top of the marker with a known distance.

© Draganfly Innovations Inc.
Phone: 1-800-979-9794 / 306-955-9907
Email: info@rctoys.com
Web: www.rctoys.com
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Brushless motors have almost completely replaced brushed motors. Their superior power and efficiency make them the obvious choice for powering your RC equipment.  Here’s what you need to know to use them, and some helpful info on how they work.

Brushless Motor Benefits

Before going into how brushless motors work, here’s why they’re useful:

• More Efficient – Brushless motors are much more efficient than conventional brushed motors. This efficiency has been measured to be between 85% to 95% better than brushed motors.
• Less electrical energy is wasted as heat,and more is used to do useful work.
• Reduced Noise – Brushless motors have fewer mechanical parts than brushed motors, so they emit less sound.
• Longer Lifetime – Fewer moving parts are in mechanical contact than in brushed motors, reducing wear.
• Reduced EM Interference – Brushless motors emit less energy as electromagnetic (EM) waves than brushed motors do. This contributes to their efficiency, and helps reduce radio interference.
• Torque, Voltage, And RPM Linearly Related – This means that the amount of torque or RPM produced by the motor divided by the voltage put in is a constant, making it easy to predict how much power you’re going to get.

How Brushless Motors Work

On a fundamental level, an electric motor’s only job is to convert electrical energy (like that provided by a battery) into mechanical energy, like the turning of a propeller or rotor blade. There are two basic facts that allow electric motors to work:

1. Electric and Magnetic Fields are Related - That is, every moving charge produces a magnetic field, and magnetic fields can produce electric charge.
2. Magnets Interact – Magnets will align when placed near to each other. All electric motors basically consist of two magnets. One of them is permanent, the other is a coil of wire that, when charged, becomes a magnet.

The motor is designed such that the magnetic fields produced by each of the magnets are always out of alignment, causing the motor axil to rotate. This is similar to what happens when you hold a permanent magnet to a compass – the compass swings position so that it lines up with the magnets field.

With the brushed motor design, the magnetic fields are kept out of alignment by turning on the different coils of wire that surround the motor axil in succession. Metal brushes make mechanical contact with the rotating axil and the contacts with each metal coil. As the axil rotates, the brushes contact different coils. The end result is that current flows through different coils at different times, constantly changing the magnetic field and rotating the motor shaft.

It’s here that we see the main problem with the brushed design: the contact between the motor coils and the brushes causes friction, which increases with speed. The metal coils wear out over time, and are prone to sparking. They can also ionize surrounding air, creating ozone. So how can we get around these issues? The answer lies in the brushless motor design. Instead of using mechanical brushes to turn on the various wire coils, an ESC (electronic speed controller) is used instead. The ESC switches the motor coils on or off rapidly, and is synchronized to the motor axil position.

Always look for an ESC with a capacity (measured in amps) greater than that of the motor you’re pairing it with.

Some Common Terms Explained

There are a number of special terms associated with brushless motors. Here are explanations for some of the most common:

• RPM – This is a measure of angular speed, or how fast something is rotating. A motor’s RPM is simply how fast it can rotate.
• KV Rating - Remember how we said that the relationship between voltage, torque, and RPM was linear for a brushless motor? It turns out that the number of RPM provided by each volt is the same, called  the KV number. The KV number’s useful because it let’s you figure  out how many volts you need to achieve a certain RPM, or vice versa.  For an example, a 980 KV motor powered by an 11.1 volt battery would  spin at 980 x 11.1 = 10878 RPM with no load. The KV rating always  assumes no load on the motor, so the actual RPM that your achieve  will be less than the one you calculate.
• Continuous / Burst Current – Continuous current measures how much current a motor can handle continuously, for an extended period of  time. Burst current measures how much current a motor can handle for a short amount of time, about a few seconds.
• Current Rating – This is the maximum current that a given motor can handle, measured in amps.
• Inrunner / Outrunner – These are the two major brushless motor  designs. An inrunner brushless motor has stationary coils, and a   rotating permanent magnet inside the coils on the motor shaft. An outrunner  brushless motor is the opposite, it has a rotating permanent   magnet, placed outside the stationary coils on the motor shaft . Outrunner motors have lower KV ratings, so they run at a lower speed with more torque. This could allow you to direct drive larger props without a gearbox. RC cars and boats tend to require inrunner brushless motors, rather than outrunners.
• Torque - Torque is a measure of angular force, or how much “push” a rotating shaft has.  Watt – This is a measure of power, or how fast energy is used.
• Volt – This measures electric potential, or how much “push” the electrons from a battery have. A greater voltage means that more   energy is being applied to a given amount of charge.

Choosing a Brushless Motor

Most airplane manufacturers will recommend certain brushless motors for different models. However, if this is not specified, a good starting point would be to check what other people are using locally,or search the web. We frequently visit RCGroups, RC Universe, and WattFlyer to see what the RC communities are using. If you have a brushed motor that you are replacing, choose a brushless motor that is the same physical size, and uses about the same wattage. To determine the wattage, multiply the current your old motor draws by the voltage it’s run at.

© Draganfly Innovations Inc.
Phone: 1-800-979-9794 / 306-955-9907
Email: info@rctoys.com
Web: www.rctoys.com
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The Blade MCX is a great RC helicopter, but a comprehensive guide on installing replacement parts seems hard to find. Here’s a list of all the parts that tend to break with crashes, and how to install replacements. Don’t feel bad about crashing your heli – even I’ve crashed a few times flying the blade MCX around the factory!

Replacing the Blade MCX RC Helicopter Flybar

The main flybar stabilizes the top rotor, and spins at a great speed. Because it’s built on top of the main rotors, it tends to fly off during a collision. Fortunately, it’s almost never damaged and most of the time can simply be snapped back into place. Should yours break for some reason, here’s how to install a replacement.

1. Check the Flybar For Damage – There’s very little that can actually break on the flybar, but check it against this picture to be sure it isn’t actually damaged.
2. Snap off The Flybar Linkage – You’ll find a small black linkage on the flybar (the plastic part, about 1 cm high, that dangles down freely), which connects to the top rotor blades. Snap it off gently, and place it somewhere where it won’t get lost.
3. Lift off the Flybar – The flybar is held between a black plastic clevis (the plastic holder on top of the rotor shaft). Gently spread the clevis apart using your fingers, and lift the flybar out.
4. Install the New Flybar - Slide the new flybars centre into the black plastic clevises between the top rotor blades. Line the plastic extrusions on the helicopter’s flybar up with the holes in the clevis and snap it into place. Do the same with the small linkage, snap it onto one of the plastic extrusions on the top rotor blades. It doesn’t matter which side of the top rotors you attach the linkage to.

Replacing the Blade MCX RC Helicopter Top Rotors

A severe crash can crack the top rotor blades. Repairing them with tape or glue isn’t a good idea, because it causes an imbalance that makes the helicopter hard to fly. Your best bet is to simply replace them – here’s how:

1. Unscrew The Rotor Blades – Using a small Philips head screwdriver, remove the two small screws holding the top rotor blades. Be sure to set the screws where they won’t get lost or roll away.
2. Remove The Rotor Blades – The top rotor blades lock into each other, gently pull them apart and remove them.
3. Install the New Rotor Blades – At the top of the rotor shaft, you’ll see two black holes protruding outwards. Place each rotor blade (right side up) into the shaft, and snap them together. It is possible to put the rotor blades in upside down – don’t do this. Make them look the same as the bottom rotor blades.
4. Re-install the Small Screws – Using a Philips head screwdriver, replace the two small screws that you removed earlier.

Replacing the Blade MCX RC Helicopter Landing Skid

The landing skid is one of the easiest Blade MCX parts to replace. It simply pulls off from the bottom of the helicopter fuselage. You don’t always have to replace a damaged landing skid, most of the time some thick or medium CA (super glue) can fix it perfectly.

1. Remove the Rechargeable Battery – You’ll need to hold on to the battery mount to remove the skid.
2. Remove the Skid – Grab the skid by the battery mount and pull it off gently.
3. Replace the Skid – Install a new landing skid by pushing it’s two pegs (found near the battery mount) into the holes in the bottom of the fuselage.  Be sure to do this gently – don’t damage the helicopter by using too much force.

Replacing the Blade MCX Inner Shaft

The inner shaft turns the top rotor blades. After a few crashes, the rotor head / hub where the flybar connects can become bent, or the inner shaft itself can snap. If you’re in a particularly bad crash and the inner shaft breaks, here’s what to do:

1. Remove The Battery and Skid – The battery slides out, and the landing skid can be pulled off.
2. Remove The Flybar – How to do this is mentioned above.
3. Remove The Top Rotor Blades – This was also previously mentioned.
4. Remove The Bottom Gear – On the bottom of the fuselage, you’ll find two white plastic gears. Remove the bottom one by loosening the screws on the silver washer glued to it. Don’t remove the little black screws completely because they are easy to loose. Just loosen them enough to let the bottom gear slide off. Then gently pull the bottom gear downwards and clear of the inner shaft.
5. Pull Out The Old Inner Shaft – The inner shaft can now be slid out of the outer shaft by pulling it upwards.
6. Insert the New Inner Shaft – Slide the new inner shaft into the hole on the top of the outer shaft – it should drop down easily.
7. Replace The Bottom Gear – Slide the bottom gear onto the inner shaft so that it meshes nicely with the motor shaft gear. Tighten the small black screws that you loosened earlier.
8. Re-Install All The Other Parts You Removed – Add the upper rotor blades, flybar, landing skid, and battery.
9. Test it – Make sure that turning the upper rotor blades makes the lower white gear move. If it doesn’t, then the small black screws on the lower gear aren’t tightened sufficiently.

Replacing Blade MCX RC Helicopter Rubber Grommets On The Canopy

The Blade MCX canopy is held on with small black rubber grommets. These rubber grommets can sometimes fall off and get lost, but replacing them is easy – here’s how:

1. Pick Up a Grommet – Yeah, I know this one sounds obvious, but picking up the small grommets without losing them is hard. The way that works best for me is to let one sit on a table, then press a finger down on it. The grommet should stick to your finger, and you can then place it where needed.
2. Push the Grommet Onto The Blade MCX Body – Push the grommet onto the shafts in the fuselage using your finger. Doing this isn’t easy, and it may take several tries.

© Draganfly Innovations Inc.
Phone: 1-800-979-9794 / 306-955-9907
Email: info@rctoys.com
Web: www.rctoys.com
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Draganfly Innovations was awarded the SABEX (Saskatoon Achievement In Business Excellence Award) for our Draganflyer X6 Helicopter on May 14, 2009. Nominations for the award closed on March 19, and Draganfly Innovations was made a finalist on April 14. The Saskatoon Chamber of Commerce SABEX awards are designed to promote various aspects of business excellence in Saskatchewan. The SABEX awards fall under several categories, including innovation, customer service, and several others. The New Product Award is given to a business demonstrating exceptional performance in launching a new Saskatchewan-made product or device in the last three years, which is both original and currently available to customers.

Criteria for applying for a SABEX award include the following:

• Potential for Market Expansion
• Projected Product Life Cycle
• Uniqueness of Product
• Development and Developmental Stages
• Product Age

We’re very proud to be honoured with this award, and will continue to strive for business excellence.

© Draganfly Innovations Inc.
Phone: 1-800-979-9794 / 306-955-9907
Email: info@rctoys.com
Web: www.rctoys.com
RSS: www.rctoys.com/pr/feed