Hinges the controls of a plane rc widely separated

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When mounting a plane, we must prevent the separation between the ailerons and the wing, between the control and the depth between the horizontal stabilizer and the vertical stabilizer drift and excessive. If the separation is too great would be lost between 15 and 20% of the action of the command in question.

 

If we had an airplane with a large separation we can stick tape Blenderm type in the entire length of the joint. For the control can move freely, to stick the tape by one side will try the knob is turned fully counter clockwise. Do the same with the other side.

The controls are usually bevel so that they can approach the maximum and reduce this gap.

Problems that may occur with the glow plugs

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The models used in glow engines have spark plugs that have nothing to do with the spark plugs of internal combustion engines . Glow plugs are actually having a catalytic action on the air / fuel mixture compressed . This form of operation makes very simple the ignition of the mixture and prevents the incorporation of an ignition system .
But this facility on the other hand has the difficulty that we do not know exactly when it will produce as it depends on the catalytic action of the spark plug. In the case of internal combustion engines in which a spark at the spark plug at a particular time if it’s clear and is set to do so at their optimum .

1 Problems that spark may be with glow plugs

Then in the case of motors for a single glow plug ignition when the mixture will vary according to the ambient temperature and the setting of the mixture into the carburetor. It is therefore very difficult to know exactly at what point it will produce combustion.

Ideal for ignition is when the crankshaft missing 15 or 20 degrees of rotation for the piston reaches its peak. This is because the mixture takes a few milliseconds to burn everywhere and when the piston is in its highest position, the mixture burns completely expands providing maximum performance.

Ignition advance

 

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If ignition occurs well in advance the mixture begins to expand to oppose the upward motion of the piston , and an impact that is transmitted to the connecting rod and the crankshaft is produced . The engine vibrates a lot , low power and if it works well long end being damaged connecting rod bearings and crankshaft.

Very hot ignition spark advance . The motor runs perfectly at idle , but has a tendency to produce explosions when the engine rotates faster, you can hear a series of explosions linked to engine noise. Spark plugs that are too hot for engine tend to melt easily.

On delayed

In this case the ignition of the mixture occurs when the piston is already down and not take full advantage of all the expansion mixture. The engine will have little power and tend to overheat. For 4-stroke engines can produce explosions in the exhaust.

Excessively cold plugs tend to lose too much temperature and ignition delay . The engine tends to stop after disconnecting the igniter and it is difficult to turn it to high returns . The engine picks up again when you connect power again igniter .

Hot and cold plugs
There are different heat range spark plugs depending on the thickness of the filament of the alloy used , the number of turns , etc. … Thus each type of spark plug more or less heat stored in the area where their catalytic action occurs.

A hot spark plug keeps more heat in their filaments and tends to advance the ignition. Cold plugs act in reverse.

2 Problems that spark may be with glow plugs

Choice of glow plugs

For the choice of the most appropriate spark plug we have in mind the instructions of the motor. We present the spark plug heat range varies from one brand to another , thus a colder plug half of a mark may be hot for another.

In principle, small-displacement engines usually need hotter plugs. The colder spark plugs are often used in larger displacement engines with high compression and use of more concentration of nitromethane.

If a motor is mounted resonator , we opt for a colder spark plug that used with normal escape. Engines mounted resonators or nitromethane are used extensively increased pressure in the combustion chamber and hence temperature , which tends to advance the ignition.

4 stroke engines need hotter plugs because combustion occurs only every two turns of the engine .

Lifetime spark plugs

The glow , same plugs if they fail to melt, have a limited shelf life. The filament of a spark plug used with time spent and loses some of its catalytic properties . For flights that are not racing should change the spark plug every 20 flights . For competition spark plugs every 3 flights are changed to maintain maximum engine performance.

What to do if an engine blows a spark behind the other

Most often this occurs because we are feeding the spark plug with too high a voltage . Spark plugs are usually designed to be fired with a voltage of 1.5 volts. A Ni- Cd battery of 1.2 volts is enough to heat a spark plug, but if you use a power supply and this tends to give more voltage than would regulate to the source of the problem . You can use a multimeter to check the voltage supplied to the spark plug.

You can also occur :

The type of plug used is too hot for our engine so it a try with a colder plug.
Engine runs superheated open more fuel needle .
Exhaust too short.
Nitromethane or too excessive compression .
Presence of metal chips within the motor. We will open the engine to check and there remains, clean it well with methanol . Upon melting the filament plugs can also detach it remains .

The flybarless system in detail

Flybarless system with bar flybar Bell or deleted , making the helicopter flight and look more realistic. The bar provides stability Bell helicopters to stabilize the swashplate .

 

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When removed it , it’s up all the work of a number of stabilizing gyroscopes, a minimum of two sensors (one for pitch and one for roll ) and a monitoring program to regulate the movements of the mixers . The control unit is fitted between the output of the receiver and servos .
In this system gain in lightness and simplicity by eliminating the flybar rod, the paddles , the flybar arms , the carrier and the washout . Result of a lighter and less effort cyclical movements are faster .

With light winds you can fly the helicopter almost unaided, due to its high stability . Increased autonomy , power , maneuverability, accident that there are fewer parts may be affected.

The Flybarless system is more expensive than the Flybar system, although that will depend on the gyro and Elected acquire virtual system and also more complicated to set up . On the other hand the absence of the servo rod Bell will have to bear more load.

There are standards conversion systems for helicopters. Among the most popular systems include the Flybarless MIKADO .

 

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Pressurization and fuel pumps for rc engines

At high engine range will often seek power , so often uses a special carburetors and fuel pumps.
The usual carburetors operate on the Venturi principle , the air passing through the carburetor venturi , passing through the narrowest part , accelerates and reduces pressure at this point , sucking the fuel through an orifice. In this way the air and fuel mixture is created . On the other hand the power of a motor is proportional to the amount of fuel that can be burned and thereby to achieve more power it tends to use larger carburetors . The problem with this is that as the inner diameter is bigger carburettor , the air passing through it decreases its speed and the pressure difference will not be sufficient enough to suck fuel . The result will be an unstable idle or medium engine speed. It also often happens that the fuel tank is away from the carburetor , which may cause doing acrobatic figures , variations occur in the fuel flow , causing changes in air / fuel ratios and may cause engine shutdown .

 

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Pressurization 350×268 4t engine glow fuel pumps and motors rc
Engine with fuel pump
To solve these problems , a fuel pump is employed. This is a device , which allows a check of fuel at constant pressure in the throttle independently of the position of the tank in relation to the motor. In addition to the fuel pump to the arrival of this carburetor is less dependent suction produced by the motor , allowing the use of larger diameter carburetors .

Operation of the fuel pumps

All fuel pumps typically operate by pressure variations , by way of pulses , which occur within the engine crankcase . The engine casing is connected via silicone tubing to the fuel pump ( as short as possible ) , in the interior of the pump is a chamber with a movable membrane , at the other end is a series of valves that only allow fuel flow in a direction toward the carburetor . A control device keeps the pressure between the values ​​measured.

Pumps ” Perry ” engines chainsaws derivatives ( carburetors Walbro ) and all OS engines with fuel pump , operate on this principle.

Installation and Adjustment

 

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Derivatives chainsaw engines feature an integrated pump and the carburetor needs no installation. In engines O.S. installation is more complicated , you need to have a tube connecting the crankcase to the fuel pump and two tubes, one to allow forwarding of excess fuel and one for attaching the fuel pump and the carburetor and sensor to control the vacuum level of the diffuser . Fuel pumps are already regulated source and is not recommended factory settings vary .
If you want to install a fuel pump to an engine that brings series, we use a fuel pump ” Perry” . The pump consists of a cylinder with three connections . One of them , in the lower part it is connected to the engine crankcase . The second is connected to the fuel tank and the third lead the fuel to the carburetor . The last two connectors are separated by a hexagonal nut for regulating the pressure of the pump. To regulate the Perry pump , following instructions , turn the adjustment screw until it is 2 mm from the edge of the housing . If the carburetor is too rich , will loosen the screw 1/4 turn at a time until you find the correct setting. Be careful not to tighten the screw too much as we can break the inner membrane.

 

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Pressurization perry pump installation and fuel pumps for motor rc
Installing a typical pump Perry
Maintenance of fuel pumps

Fuel pumps for possessing membranes , valves and small ducts can become clogged or damaged and therefore installing a good filter between the tank and the pump, in addition to using quality fuel is needed. This filter has to be cleaned and inspected regularly.

 

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Pressurization rc fuel filter and fuel pump motor rc
Fuel filter
The fuel pump can be cleaned by introducing methanol into it and leaving it on for some time thereby plugging the holes to prevent evaporation .

Pressurization of the fuel tank

There is a simple and inexpensive way to ensure fuel supply carburetor art. Is to pressurize the fuel tank .

Today crankcase pressure and not normally used as a pressure source for pressurizing the fuel tank, because it is in the form of pulses and high and carburetion obtained is not very good. However the exhaust pressure is lower but is more stable and varies according best engine speed so that it is more suitable to pressurize the container .

350×158 pressurization tank pressurization and fuel pumps engine rc
Installing the tank pressurization system
The majority of the engine exhaust are provided with a power series to be connected to pressure the fuel tank via a silicone tube . This system works well for most engines and gives a stable engine carburetion .

The servomotor in radio

The servo , in radio , is responsible for transforming the commands sent by the receiver in a rolling motion has turn through transmissions attached to control these movements become offset or translation. There are a variety of servos that are differentiated by their size, torque ( kg.cm ) , rotation speed . There are also piñonería and servos with metal bearings.
rc servo scheme 350×214 The servomotor in radio
Schematic of a servo for radio
Running a standard servomotor

A servo is constituted mainly of a motor and a reducer . The output of this movement is a rotation . Once the motor rotates , the servo axis changes position , which changes the resistance of the potentiometer. The function of the control board is to control the motor so that the position of the output shaft is according to the order received from the receiver.

The order consists of a small electrical pulse whose duration is between 0.5 ms and 2.5 ms. The value of 1.5 ms gives the center position servo . Positions orders are transmitted in the form of a pulse width encoded signal , repeated periodically, typically every 50 ms , which enables the control electronics to continuously correct the angular position of the output shaft .

Increasing the amplitude of the pulses acting on the control of the speed , until the servo arm is at the desired position. During rotation , the potentiometer indicates to the electronic circuit the time when the desired position is reached . The impulses then decrease in amplitude until no voltage is applied to the servo motor , keeping the arm in its new position .

Disadvantages: the pulse is strong and instantaneous, without any continuity in the rotation started as might occur to a DC voltage . Small movements in the stick of the transmitter produced only small effects on the servos. They can become ineffective and causes the major neutral zone that characterizes traditional servos.

Differences between digital and analog servos

Digital servos also have an electric motor and potentiometer engranages reducers , but differ from the analog by the fact that with a microprocessor which analyzes the signal received from the receiver and controlling the servo motor signal.

The main difference lies in the way to treat the information received from the receiver and the control exerted on the voltage applied to the motor , allowing to reduce the dead zone , thus increasing the range of motion and generating a static positioning stability .
Advantages of digital servo

A larger amplitude and pulse duration .
The pulses are of higher frequency : 300 pulses per second versus 50 pulses per second in the case of analog servo.
The engine reacts better to the order given .
A decrease in the neutral zone leads to a faster response , quick acceleration , and a gradual stop.
Improved stability in the static position .
Disadvantages of digital servo

A higher power consumption .
connections

A ground wire ( black )
A power supply voltage to 5V (red )
A power control voltage 0- 5V ( white)
Maintenance of a servo

The servomotors of our reduced models are the components that suffer most. Withstand shocks , stress , leading to breakage of the gears. Measures have to perform maintenance :

Regularly clean the connector contacts with spray cleaner .
Engranages Check and lubricate with silicone grease .
Clean the pot with clean contact spray.
Check that there is no broken welds or poor contacts.
Check fixing all the cables inside the servo.
Check rubber protection against vibrations ( which are interposed between the servos and the model).
Protective measures to consider

Introduction of a weak point between the servo and control model element . This weakness must resist the orders given on impact but must yield to the force of the shock is not transmitted to the servo , thus avoiding their gear roper . You can use quick -links or plastic pegs .
There are protections that are called servos salvation . The 4 × 4 remote control cars usually have a salvation servos on the front wheels . Systems are also easy to make for the front wheel of an airplane ( tricycle gear ) .
May be used provided servos ball bearing in the output shaft to prevent the occurrence of gaps or games.
You can buy servos with metal gears to better withstand vibrations.
scheme saves servo rc car radio control servomotor
Schematic of a typical servo salvation of a rc car ( steering servo )

 

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rc plane servos saves 350×200 The servomotor in radio
This bent rod will absorb part of the impact. It is widely used in model aircraft, for example the front wheel of a tricycle gear .
After an accident

Check the housing , the locking tabs , arm and the gear train .
repairs

 

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Perform soldering with a soldering quality and fine point .
Use quality tin . Before applying resolder a wire tin before removing it with the soldering iron to remove the old and tin impurities . After soldering tin will never be shiny off.
Remove the servo in the correct order , the screws , the output shaft , gears , electronics, motor and potentiometer.

 

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In what is the Flybar Bell or bar

The Bell flybar or rod acts on the main rotor of the helicopter, stabilizing to the cyclic shift and relieving the load on the servos.
The flybar acts in 3 ways:
Flybar reduces the load of the servo because the load-bearing cyclic servo is partly relieved by the flybar.
Provides gyroscopic stability against destabilization due for example to wind resisting this force parallel to the main rotating rotor with a rotor outward force, which causes the main rotor causes cyclical movement of the rotor inwardly thereby balancing the helicopter.
Offsets the effect of rising angle of the blades in rapid f

ight.flybar

Explaining why a collective pitch helicopter tilts steady

All radio controlled helicopter collective pitch, leaning on hover clockwise to those in which the rotor rotates clockwise and counterclockwise for the other.
Is due to the principle of action and reaction: all the forces acting on a motionless object must vanish. In the case of a helicopter, the forces are the same weight, strength and the tail rotor.
Weight is the vertical direction, the resultant force of the tail rotor to the right, then the main rotor should push a little to the left to compesarlo and as a result the helicopter tilts to the right.

 

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Shooting and adjusting a gasoline engine 2-stroke

The shooting of a gasoline engine is different from the need for a glow engine , in this article we will see how to correctly shoot a 23 cc gasoline engine .
rc gasoline engine airplane 350×337 Shooting and adjusting a gasoline engine 2-stroke

 

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Before starting the shoot we perform a correct fuel mixture. Lubrication of a 2-stroke engine is made by the oil dissolved in gasoline. This lubrication ensures a good engine in terms of power , prevents seizing and prolongs engine life .

The amount of oil in the mixture can be expressed :

As a percentage of total volume ( between 2 and 4%).
In proportion gasoline / oil ratio called .
For example , whether to prepare a mixture of unleaded gasoline with 3% oil mixture for 1 liter of petrol will use 97 cl cl and 3 oil (1 liter = 100 cl and 1 liter = 1000 ml ) .

Whether to prepare a mixture ratio of 32:1 will rule 3:

32 parts unleaded ——> 1 part oil

1000 ml of unleaded —–> x ml oil

x = 1 * 1000/32 = 31.25 ml of oil per 1 liter of unleaded petrol.

We recommend using 100% synthetic oil .

To shoot use a mixture of 4 % oil the first hour and a half of operation for the engine to run well lubricated . For the rest of the shoot oil 3% will be used. Once the motor is properly grounded may use a mixture of 2.5%.

We run the engine for 3 intervals of 30 minutes to 1 /3 of its revolutions and letting cool between each interval.

After this period , it is to regulate the maximum speed as well as idling. From here you can use the engine but during the 20 hours following the mixture of 3% is used and not seek to force the motor.

 

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Engine setting

Running 350×320 walbro carburetor and adjusting a gasoline engine 2-stroke

Carburetor find 3 essential screws to regulate motor operation :

H ” High” to regulate the operation at high spin.
L ” Low” to regulate the operation at low revolutions .
The idle adjustment screw .
The idle adjustment screw is made ​​by adjusting the carburetor and also using the station.

To regulate the operation at low engine suddenly accelerate from idle . If the engine tends to stop snitching or to achieve a high rate , then we will open the screw L low to enrich the mixture . It is to open 1/8 turn at a time . When we pass the engine at high idle turns firmly be in the correct configuration.

High screw H is used to regulate maximum engine rpm . The more we close further impoverish the gas mixture and the engine turns faster until a safety limit to be respected for not overheat or damage . This limit will be indicated in the engine manual. (eg not close more from the two laps of the screw).

It is said that the action on each screw high or low affects the operation of idling and each other. So it is possible to have to reset them repeatedly until you find the correct setting.

 

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How to clean the calamine of glow engines

Calamine is a residue formed during the combustion and which is deposited in the whole combustion chamber , valves, etc … in time hinder the flow of the gases and preventing the valve seal .
To minimize the formation of calamine and preserve internal performances of our engines , we may occasionally use a cleaner / degreaser for ECOTEC engines ( for 2 and 4-stroke automotive specialty stores ) .

To do this turn on the engine and let it warm up, then we put back the spark heated and accelerated to stop it since the engine and repeatedly pulverized with carburetor cleaner through . If we do not put the spark heats the engine will stop . This process must do it outdoors as toxic gases are produced.

 

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How to clean piston 317×350 calamine calamine glow engines
Piston Head black with calamine
This product eliminates calamine on the piston and on the valves . It also prevents the compression piston ring sticking and cleans the entire combustion chamber.

After that empty the fuel tank , turn on the engine to turn off after running out of fuel and we take a few drops of anti-corrosion oil 3 in 1 by the spark plug hole and carburetor. We strongly crank the engine a few seconds and is ready for the next use.

Features broadcasters rc helicopter

There are special digital stations in the market to pilot helicopters, with features that improve the management of these devices. These stations tend to be medium or high range and eliminates interference from stray producing the helicopter at close range ( due to the movement of many metal parts ) .

 

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The minimum number of channels required to handle a helicopter are four, although much of the helicopters need 5 channels. In addition to these five , a sixth channel is often used to regulate the gyroscope . Consequently , the special stations for helicopters have 6 or 7 channels.

Features 308×350 helis station stations rc helicopter

A channel will act in the longitudinal cyclic to tilt the helicopter forward or backward (on a plane is the depth ) , while another channel is used by the transverse cyclic tilting the helicopter to one side or the other (on a plane are ailerons ) .

Another channel acting on the tail rotor causing the helicopter to rotate about its vertical axis in one direction or another ( in the plane is derived.)

The engine is also regulated by another channel as in an aircraft radio .

Another essential function in modern rc helicopter is the collective pitch that varies the angle of attack of the main rotor blades , regardless of cyclic pitch . By increasing over the helicopter go up and vice versa. Increasing collective pitch must be accompanied by an increase in engine acceleration coordinated.

This feature is one of the key roles in a radio helicopters.

Mixing function step / motor

This feature greatly facilitates piloting a helicopter since the variation of the motor function of blade pitch does not behave linearly for each engine speed and stable rotor.

A normal helicopter requires a minimum pitch of between 2 and 4 degrees negative . Do a stationary positive about 5 degrees and the maximum step is about 8 degrees positive . The carburetor opening will be located in the middle and go from 5 to 8 degrees collective gas must be fully open .

In normal flight , the minimum step , the engine must run with a fast idle.

That is, the engine carburetor as you move the stick forward the station will open little at first and increasingly at the end.

The radios can be configured helicopter servo displacement gas and function of collective pitch stick movement . Although a single stick is used in the station, it has two trims ( casters ) separated to act quickly and conveniently on the gas mixture and collective pitch way .

At later exponential stations available to regulate the amount of displacement of the servo involved in either direction ( ATV function ) .
This way you can properly configure the operation of these servos to hover as getting satisfactory ( ” Hovering pitch” and ” Hovering throttle” ) .

Tail mixing function

The mixing function or anti-torque tail is specific helicopter stations . Its function is to correct the tendency of the helicopter to turn to changes in collective pitch . When the helicopter flies , the torque produced by the engine causes the main rotor to rotate in one direction while the rest of the helicopter tends to rotate in the opposite direction (according to the law of action-reaction physics ) . This force must be balanced by varying the pitch of the tail rotor blades . The variation of this step should be adapted to the collective pitch : if the gas and step increases , you must increase the pitch of the tail rotor blades , and otherwise, must decrease.

This coordination is done by a mixer that handles the tail rotor independently and also if you get the order of the stick of the transmitter to turn tail , do it.

This action complements the transmitter gyro tail if it detects a change in the tail that is not ordered by the station acts on the tail rotor counteracting the action.

The stations usually have 3 positions for the glue mix . You can also set your tabs to the main rotor . They also have two potentiometers “Revo up” and ” down Revo ” corresponding to the mixture between stationary and maximum pitch tail rotor , and stationary and minimum pitch of the tail rotor.

 

Pre-acceleration ( Idle- up)

The pre-acceleration is a special feature of the helicopters used to perform stunts without losing control of the device. Recall that the control system depends directly on the helicopter main rotor . When you run a looping or a barrel , the helicopter is put upside down for a few seconds . Sorry if we are not losing much height (the main rotor vents to above) , we reduce the step or apply a negative step. In normal configuration this means cutting the engine with consequent lowering of the main rotor system and loss of control of the helicopter.

This problem can be reduced thanks to the Idle- up . It is a device that allows the station has as the pitch of the blades is to specify how slow the main rotor is reduced.

Autorotation “Hold”

Helicopters same with the engine stopped and sufficient height can land perfectly . With good training and good set , if the engine is cut in flight , it is possible to lower it to the ground and it lands softly. In fact it is one of the figures present in competitions. The “Hold” feature allows autorotation practice without the risk of breaking . When pressing the interuptor , the throttle takes a certain position such idle and you can practice autorotation . At the desired time you can return to action and regain control of the motor. Potentiometers available to regulate the speed of rotation of the rotor in the “Hold” position .