Product Announcements July 28, 2008
The BR-ADAPTER is a power supply for charging your BladeRunner, Micro Mosquito and Firefly RC helicopters.
This power supply can be used to charge your RC helicopters, without using C batteries. Because C batteries have a limited lifespan, using this adapter will save you money over time. The BR-ADAPTER plugs in to either the transmitter, or the charging base station. When using the BR-ADAPTER, you don’t need batteries in either the transmitter or the base station.
The BR-ADAPTER plugs in to any standard 120V AC outlet, and provides 500 ma of current at 6 volts. Please note that you need to have either a base station or transmitter to use the BR-ADAPTER. Both of these products are available separately on our website.
Use the BR-ADAPTER to power your indoor RC helicopters, and save money on batteries.
You can simulate aerial combat with your RC model airplanes without excessive risk to your models. Here’s how:
- Find as many friends with RC model airplanes as possible.
- Divide the available RC model airplanes into teams
- Attach different colored streamers to each RC model airplanes tail, depending on which team that it’s on.
- Have all the RC planes take off at once
- The object of the game is to use your RC model airplanes propeller to cut the streamer off of our opponents.
- After a set amount of time all of the planes land and the length of their streamers are measured. The team with the most streamer remaining wins.
This game can be played with any number of RC model airplanes, but keep in mind that the risk of a collision increases with the number of RC model airplanes flying.
Flying the Limbo
This is one of the easiest games to play, but it’s also the most risky. To play,simply find a large football or soccer field and fly your models through the goal posts. Make sure that you are allowed to fly your models in the field that you’re using, and that there are no people in the field that could get hurt -should the airplane crash.You can also construct a makeshift goal post out of PVC pipe, found in most hardware stores. Cut the pipe to a decent length, and then friction fit it together using PVC fittings.
- Find a rectangle of balsa wood, at least as long and wide as the payload that you intend to carry on your RC model airplane.
- Horizontally mount a spare servo to the end of balsa wood. Make sure that the servo arm points upwards and rotates 90 degrees when activated.
- Stretch a rubber band over the two corners of the balsa rectangle opposite the servo, and then loop the rubber band over the servo horn.
- Mount the whole apparatus on your RC model airplanes fuselage, and connect the servo to your receiver.
After the servo moves, the rubber band slips off the horn. If you place your intended payload under the rubber band, you can drop it from your RC model airplane at the flick of a switch. Take a look at this picture, which shows one such design completed and loaded with plastic parachute toys.
You can make bombs to drop out of Styrofoam cups, rubber cement, and talcum powder. Here’s how:
- Place one Styrofoam cup on a flat work surface, and fill it with a few tablespoons of talcum powder. Take a small paint brush, and coat the Styrofoam cups rim with a small amount of rubber cement.
- Place another Styrofoam cup on top of the first, lining up the rims.
- Let the cups dry
- Take a hobby knife and cut a cross section into one of the cups.
- If you like, spray paint the bomb and add cardboard fins.
After the bomb hits the ground, the cross section that you cut into the nose will cause it to shatter, releasing the talcum powder it contains. When it works, this looks a lot like the cloud of smoke and debris that real bombs leave after exploding. After you drop the bomb, be sure to watch your airplane and not the resulting cloud of powder.We hope that you enjoy playing these games with your RC model airplane. Be safe,and have fun.
RC Airplanes July 24, 2008
Many RC model airplanes lack a conventional landing gear and need to be hand launched. This article will show you how to properly hand launch an RC model airplane.
When you’re learning to fly try to find a hill to launch your RC model airplanes from. This will give you a bit of altitude right after takeoff, which provides more room to maneuver during the initial climb. Follow this procedure to successfully hand launch an RC model airplane:
- Turn both the transmitter and the receiver on.
- Hold the RC model airplane at it’s center of gravity (balance point) with your throwing hand and hold the transmitter in your other hand.
- Make sure that the RC model airplane’s nose points downward slightly and that the wings are level.
- Increase throttle to full.
- Toss the RC model airplane forwards like you would throw an overhand baseball.
- As soon as the RC model airplane leaves your hand, quickly move your hand to the transmitter and begin flying.
- The initial climb should be straight and gradual, using only small control inputs.
Some RC pilots prefer to launch their aircraft by taking a running start. There is nothing wrong with this method, just make sure that there is nothing in your path that you can trip on. Take a look at this sequence of pictures, which shows what a good hand launch looks like.
Now that you know how to properly hand launch an RC model airplane, get one on RCtoys.com and go flying!
Information Articles July 23, 2008
Even with the advent of spread spectrum technology, many RC aircraft pilots still use the 72 mhz frequency band. If you use a conventional PPM or PCM radio system, it’s very important that you be aware of the different frequencies and frequency control methods used by RC pilots. Failure to observe which frequencies are in use at any given time can result in the loss of one or more RC model airplanes due to radio interference.
Every FM RC model airplane operates on a fixed frequency. Groups of frequencies are divided into channels. Each specific frequency is given a channel number. This table lists the different frequencies found in the 72 Mhz band, and their respective channel numbers.
72MHz Channel / Frequency Table
|11 / 72.010||28 / 72.350||45 / 72.690||12 / 72.030||29 / 72.370||46 / 72.710|
|13 / 72.050||30 / 72.390||47 / 72.730||14 / 72.070||31 / 72.410||48 / 72.750|
|15 / 72.090||32 / 72.430||49 / 72.770||16 / 72.110||33 / 72.450||50 / 72.790|
|17 / 72.130||34 / 72.470||51 / 72.810||19 / 72.170||36 / 72.510||53 / 72.850|
|20 / 72.190||37 / 72.530||54 / 72.870||21 / 72.210||38 / 72.550||55 / 72.890|
|22 / 72.230||39 / 72.570||56 / 72.910||23 / 72.250||40 / 72.590||57 / 72.930|
|24 / 72.270||41 / 72.610||58 / 72.950||25 / 72.290||42 / 72.630||59 / 72.970|
|26 / 72.310||43 / 72.650||60 / 72.990||27 / 72.330||44 / 72.670|
If you fly at a club, there will normally be a frequency board posted with the information above. Before any pilot turns on their radio system, they are expected to place a clip or pin on the frequency that they will be using. This ensures that each radio is operating on a separate frequency, and prevents many interference caused crashes.
Lithium Polymer Batteries July 23, 2008
Does Temperature Affect Lithium Polymer Batteries?
Yes, lithium polymer batteries are affected by temperature. All batteries use a chemical reaction to provide electricity, and a low temperature slows this reaction down significantly. You cannot harm a lithium battery by running it at a low temperature, but you will notice a significant decrease in performance. Allowing lithium polymer batteries to freeze is generally not recommended, so be sure to store the lithium battery in a cool, dry location over the winter months.
What does “3S4P” mean?
Every lithium polymer battery consists of a set of individual cells, which can be wired in either series or parallel. Cells wired in series (positive to negative) increase the overall voltage of the pack, while cells wired in parallel increase the capacity. As an e 3S4P pack consists of 3 cells wired in series, and each array of three cells is wired in parallel four times. This means that the pack consists of twelve cells in total. Because all 3S batteries consist of the same number of cells wired in series, they all have the same voltage.
How can I calculate theoretical flight time?
In order to calculate the maximum theoretical flight time of your models, you will need to know some information about your battery and motor equipment:
- Motor Amperage
- Pack capacity in Mah (milliamp hours)
After you have that information, you can use the following formula to compute the maximum theoretical flight time of your model:
Time (hours) = (battery capacity (amps) / (motor current (amps)
Notice how the battery capacity must be given in amps. To find your battery capacity in amps, divide the capacity in milliamps by 1000. You will probably want the result expressed in minutes. so multiply the time you just calculated by 60.
By this formula, a 33.5 amp motor powered by a 5000 Mah battery would have a run time of a run time of 8.96 minutes. This is a theoretical maximum, if you actually ran the above set up for the calculated maximum time you would destroy the battery. Most lipo batteries shouldn’t be discharged below 80%, so multiply the calculated time by .8 to account for this.
What does the C rating mean?
The C rating is a measure of how long it takes a battery pack to discharge under a given load, expressed in fractions of an hour. As an example, a battery discharging at 1C would be empty in 1 hour, a 2C discharge would empty it in 1/2 an hour, and so on. For example: a 4000 Mah battery being discharged at 4000 ma, then it would be empty after an hour, and discharging at a rate of 1C.
I’m converting my RC vehicles from Nicd or Nimh to Lipo – what equipment do I need?
That depends on the type if speed controller that you’re using. If it’s marked as lipo friendly, then you don’t need to replace anything but the battery. Otherwise, it’s best that you get a speed controller that has been specifically designed for lipo batteries.
How many cycles will a lipo battery last for?
There is really no clear and concise answer for this question. The lifetime of the lipo battery really depends on how it was used. If you over discharge, over charge, or drain the battery at a higher C rating than it was intended for it will not last long. If you take care of your batteries, and are careful to follow the manufacturers instructions, you can expect to get at least 300 cycles during the lifespan of the batteries.
Is it true that the storage of the battery can effect the performance?
Yes, it is. How you store the battery severely affects it’s capacity, and thus it’s useful lifetime. You should not store lipos at 100 percent charge, and you should not store them at near minimum voltage. Either of these situations will result in the battery internally “rusting away”, and will decrease it’s capacity over time. The best way to store a lipo is at about a 50% charge, in a cool, dry location.
Is there really a way to “recover” over discharged batteries?
No. Despite claims that some chargers and settings can miraculously “restore” over discharged lipos, no charger will undo the permanent chemical reactions which take place within an over discharged cell.
With the support of our customers and friends all over the world, 2007 was another exciting year for Thunder Power RC. Introductions of the High Grade series ESCs, along with the innovative, industry-first ‘Balance Discharge Monitoring and Protection’ equipped Smart Guide series ESCs, saw the TPRC product line grow beyond Li-Po batteries, balancers and chargers. The exciting acquisition of Insane Foamies, manufacturer of premium 3D foam airplane models from some of the world’s best pilots and designers, like Mark Leseberg Jr., further expands TPRCs product offerings in a continued commitment to bring high quality, high performance and high value products to RC modelers worldwide.
New Thunder Power Extreme V2 Series Lipo Batteries
Rounding out 2007 was the release of eXtreme V2 series LiPo batteries, the next evolution in the ever-popular 25/50C discharge capable eXtreme series of premium performance batteries. Offering higher voltage under load for added power, cooler operating temps and significantly improved cycle life, eXtreme V2 series batteries continue to be the battery of choice for the world’s top 3D airplane and helicopter pilots who demand nothing but the utmost in power and reliability, including TPRC team pilots Quique Somenzini, Alan Szabo, Jason Krause and many more. And now in 2008, hot on the heels of Align’s latest release, Alan and Jason are using the all-new eXtreme V2 series 2600mAh batteries to power their T-REX 500 helicopters, offering 6S performance that has to be seen to be believed. Available in configurations from 2S to 6S, the eXtreme V2 2600mAh series batteries round out the eXV2 line nicely while offering the perfect power solution for many larger park flyer to mid-size airplane and helicopter models.
In only a few short months, 2008 brought even more exciting product announcements and releases, including the overwhelmingly popular TP-610C ‘all-in-one’ charger, discharger and balancer. This innovative and unique charger not only offers the versatility of 1-6 cell LiIon, LiPo and LiFePo4/A123 charging and discharging capabilities, but also the convenience, added safety and increased battery performance offered by a built-in balancer that constantly communicates with the charger throughout the charging process. Best of all, the TP-610C also offers 1-14 cell Ni-Cd/Ni-MH and 6-24V Pb/lead acid battery charging (and discharging/cycling) capabilities, at rates from 0.25 to 10-amps, all at an incredibly affordable price that makes it the number one choice of demanding airplane, helicopter and surface modelers alike. Never before have so many features, so much versatility and so much convenience been available at such a great price.
The first weekend in April brought the 54th annual Toledo Weak Signals RC Expo, where the new Thunder Power RC 325mm carbon fiber main rotor blades for 400-450 class helicopters were released. These ‘true’ 325mm long (measured from center of mounting hole to tip) rotor blades offer increased disk area for reduced disk loading, while offering extra power and ‘pop’ for aggressive 3D maneuvers when compared to other similar class blades. Their unique carbon fiber and foam core construction results in incredible stiffness for unbelievable stopping power and response, while the high-quality resin and ‘painted in the mold’ finish offers great looks on the ground and in the air. A perfect fit for Align T-REX 450 and other 450-class helicopters, plus including shims for use and easy installation on E-flite® Blade® 400 helicopters, TPRC 325mm CF blades offer all the performance of top-brand blades, at a fraction of the price, making them the perfect blades of choice for almost everyone, including aggressive 3D helicopter pilots Danny Szabo, Marcus Kim and more.
We are also introducing the new 250mAh and 350mAh Pro Lite series batteries. Andrew Jesky flew the new 2S 250mAh battery to a first place finish at the 5th annual Electric Tournament of Champions, while fellow TPRC team members Jason Noll, Mark Leseberg, Ryan Archer and more took advantage of the low weight and 20C/30C discharge capabilities to finish in many of the other top spots. These 250mAh batteries, along with the new, smaller footprint 350mAh batteries, will continue to be the choice of top precision 3D aerobatic pilots worldwide for many of this year’s most demanding indoor contests. They’ll also be the perfect choice for micro flyer and slow flyer pilots looking for minimum weight, maximum performance and maximum reliability at a
Thunder Power Race Series Lipo Batteries
The Toledo show also brought a sneak peek at the all-new TPRC Race series LiPo batteries for RC cars and trucks. Factory-matched cells housed in application-specific designed, impact-resistant cases will offer a level of power, performance and reliability never before seen from Ni-MH and even other LiPo battery offerings in the surface market today. The first release of 2S 7.4V batteries, in capacities from 3300 to 5400mAh, will deliver maximum continuous discharge rates up to 30C, offering sport and serious racers alike the perfect, drop-in fit battery for almost any 1/10 scale application – from on-road oval and touring cars, to off-road buggies and trucks. Be sure to look for Race series LiPo batteries and accessories in stores this summer.
With these and many more new announcements and releases to come, we look forward to another year more exciting than the last!
RC jet engines represent some of the most impressive technology that the RC industry has ever created. RC jets are always an amazing sight at the flying field, because they look and sound just like the real jets you find at airports and military airfields. In this article, we will take a look at how model jet engines work, and show you the differences from full scale jet engines.
Before you go out an buy a jet, be warned that RC jets are some of the most complicated, expensive, and difficult RC model airplanes available. You will need both many hours of flying experience and a huge budget to successfully own and fly an RC jet.
This article is about real jet engines which burn kerosene (or jet A1), not the electric ducted fan models frequently found in hobby stores. EDF jets are great models to fly, and some are capable of advanced aerobatics, but they are not to be confused with real RC jets using real jet engines.
How Full Scale Jet Engines Work
In order to understand how model jet engines work, it is helpful to examine the full scale engines used by airliners and other jet aircraft. A jet engine is a device which operates inside a fluid (in most cases air), and expels it at high speed achieving a propulsive effect. The mechanics of jet engines are best represented by Newton’s laws of motion, specifically: “For every action, there is an equal and opposite reaction.” This means that the reason jets go forward is because they expel air backwards, faster than it came in. This basic principle applies for all types of jet engines.
But how do we achieve the movement of air needed to propel an aircraft? We know from high school chemistry that the volume and the temperature of any gas are proportional. Because of this, when air is heated, the volume increases. If the air is held in a container (the combustion chamber of a jet engine), then the pressure will also increase. Releasing the heated gas will result in an exit speed greater than the speed at which the air entered, creating the backwards flow of air needed to travel forward.
Interestingly enough, rockets are considered to be a type of jet engine. The only difference between a rocket and a conventional jet engine is that the rocket operates in a vacuum, and thus needs to take both fuel and an oxidizing chemical with it. The discussion of rockets and other exotic jet engines is beyond the scope of this article, so we will limit our investigation to three of the most common designs. These jet engines are listed in order of complexity, and all were used in full scale aircraft at some point in time.
The Pulse Jet
The pulse jet is one of the simplest jet engines, consisting of little more than a pipe and a fuel source. Pulse jets were used by Germany during World War II to propel primitive cruise missiles (V1 flying bombs). A pulse jet works by igniting a fuel air mixture in high frequency bursts. A typical pulse jet cycle operates as follows:
- Air is allowed to enter the combustion chamber, and fuel is simultaneously added.
- The intake valve is closed.
- Ignition is triggered, resulting in an outward flow of air and low pressure inside the combustion chamber.
- The valve is opened, and new air rushes in due to the low pressure in the combustion chamber.
This cycle repeats during the entire operation of the engine.
Pulse jets are not very efficient, and are extremely loud. Because of this they are not often used in full scale aircraft, but hobbiests often build them due to their design simplicity and lack of moving parts. In some cases, pulse jets are built to small dimensions and used on RC model airplanes.
More sophisticated jet engines use turbines to compress the air fuel mixture before igniting it. A turbine is a device which consists of sets of moving blades attached to an axle. If the turbine blades are spinning, they will move air through themselves and towards the back of the vehicle. This figure shows a moving turbine, spinning on an axle.
The operation of a turbojet is represented in this figure.
Unlike pulse jets, turbojets lack a repeating cycle (the engine operates continuously). There is a sequence of events that occurs during the engines operation though, so we list them here in chronological order.
- Air enters the turbine and becomes compressed.
- The compressed air is routed to the combustion chamber, where is is mixed with fuel.
- Ignition occurs, and the resulting hot air is allowed to exit the jet engine.
- Before leaving the engine, the hot air is forced through a gas turbine, which drives the compressor used in step 1.
Turbojets are far more efficient than pulse jets, because some of the energy produced by the combustion process is reused
Even though turbojet engines are more efficient than pulse jets, they are not often used in subsonic aircraft because of the noise they produce. Turbojet engines are well suited to high speed operations, exceeding the speed of sound. They become less efficient at the subsonic speeds which airliners and other commercial jet aircraft operate at.
The turbofan design operates on exactly the same principle as the turbojet engine, but instead of routing all of the intake air through the combustion chamber a small amount is allowed to exit unburned. Instead of being mixed with fuel and burned, some of the cool air is mixed with the exhaust, reducing the exhaust speed and increasing fuel efficiency. This figure illustrates the operation of a turbofan jet engine:
How Model Jet Engines Work
RC Model airplane jet engines work in exactly the same way as the full scale ones discussed above, with the exception of the air compression. Instead of using an axial turbine compressor, RC jet engines use a centrifugal compressor. A centrifugal compressor propels air outwards after it enters the engine, causing it to hit the engine case and be compressed. Centrifugal compressors need fewer moving parts than axial turbine compressors, and are more efficient for small applications. Many small full scale jets use centrifugal compressors for the same reasons.
Here is a picture of a typical RC model airplane jet engine, mounted on top of an RC model airplane.
RC jet engines operate on kerosene, exactly the same fuel that full scale jet engines use. Ignition is achieved with a small glow plug, like those found on two and four stroke RC model airplane engines.