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JAKADOFSKY Turbines
AECU Controller

In November 2010, JAKADOFSKY introducted the PRO ECU turbine controller which contains completely new control and monitoring software for our turbines. That said, there are plenty of modelers who will continue to use the original AECU control unit, and many more who are still flying the RS edition turbine.

             

Product ListFAQPRO ECUAECU  

General Turbine Operation

Modelers transitioning to turbine power need to familiarize themselves with the absent-coupling between the engine and the helicopter's collective pitch. In nearly all non-turbine model helicopters, the coupling between throttle and pitch is critical and needs to be carefully setup. Turbines are very different.

Turbine models traditionally did not use the throttle channel on your transmitter because the turbine engine speed is completely independent from your collective pitch. On the AECU, the turbine control consists of a turbine safety switch and a turbine RPM switch (3P switch, slider or dial) which consumes two channels on your radio system.

Classical Matching of Pitch & Throttle Curves

Every modeler that starts out in a glow powered model helicopter initially struggles to setup pitch and throttle curves on their transmitter. The difficulty comes from understanding how the two-stroke engine develops speed and torque as it accelerates. As modelers become more experienced with their engine and transmitter they are able to achieve a very predictable flight response. Those modelers that become proficient may also invest in a throttle governor which connects physically to the engine and will regulate its speed to maintain a fixed rotor-head RPM through all flying maneuvers.

Normal Turbine Operation = Fixed Turbine RPM

In stark contrast, the turbine engine is started and achieves idling speed, then the pilot switches to operating speed and it automatically spools up to an operating RPM with the helicopter's blade pitch in neutral. Once the operating RPM is achieved, there is a huge amount of power available and the turbine will signal the pilot using the auxillary LED and the pilot can lift the helicopter off the ground. Once in the air, the turbine speed remains very constant reacting only to the largest changes in pitch. The turbine's fundamental operation guarantees a constant rotor-head speed which can be fine tuned in the programmable control unit.

If you have the PRO ECU, you can return to the PRO ECU Setup section.

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AECU Setup: Receiver Connections for JAKADOFSKY RS, Starwood & PRO Turbine Models

Modelers configuring their first JAKADOFSKY turbine engine who have previously flown electric, glow or gasoline powered helicopters have a choice in how their turbine is controlled from the transmitter. As demand for JAKADOFSKY turbines is steadily growing, we believe that a traditional throttle configuration is equally suitable and initially is more familiar to model helicopter pilots. This is detailed in table 1, we however prefer the absent-coupling of throttle to collective pitch and use the configuration as shown in table 2.

Our first configuration shows the traditional receiver setup for turbine models using the throttle channel. The flight mode switch is used as it was intended. Turbine startup is achieved when the flight mode switch is in normal position with the throttle stick at low and the throttle trim all the way down. To start the turbine, toggle the turbine safety switch to on. After the turbine reaches its idling speed, toggling the flight mode switch to idle-up signals the turbine to spool up to operating speed by setting a flat throttle curve at 100%. Once the turbine LED signals that the engine is at full speed, collective is added to lift off the model. In terms of pitch curves, Idle-Up 1 becomes the normal pitch curve and Idle-Up 2 is used for aerobatics when additional negative pitch is perferred.

ChannelFunctionUseage
1 or 4ThrottleTurbine RPM Switch
 AileronNormal
 ElevatorNormal
 RudderNormal
5Gear SwitchTurbine Safety Switch
6Collective PitchNormal
7Auxillary 2-3P SwitchGyro Remote Gain
8AuxillaryUnused
Table 1. Throttle channel turbine RPM control.

The next configuration shows the absent-coupling receiver setup for turbine models. It is possible to use a 7 channel radio system, however most pilots prefer to make gyro gain setting changes from the transmitter to avoid stopping the rotor-head at each adjustment.

ChannelFunctionUseage
 ThrottleUnused
 AileronNormal
 ElevatorNormal
 RudderNormal
5Gear SwitchTurbine Safety Switch
6Collective PitchNormal
7Auxillary 2-3P SwitchGyro Remote Gain
8Aux switch/slider/dialTurbine RPM Switch
Table 2. Auxillary channel turbine RPM control.

Depending on your transmitter, you may have a choice for the Turbine RPM Switch. In our experience, the a 3 position switch, slider or dial are all suitable. While we do not actively change the turbine RPM during flight in helicopters, occassionally the model is flown at a location that has a different altitude or humidity that affects the engine and its operation RPM can be adjusted. Many factors contribute to what that flying speed should be including fixed elements like the model weight and rotor blade type to variable elements like the air temperature and humidity which change day to day.

Turbine Autostart Procedure - Throttle channel & flight mode switch.

StepConsoleEventAuxillary LED
1. Beginstop  
2. Throttle in low position with trim down.   
3. Turbine Safety Switch: ONrun solid on
 rel-system release for startupsolid on
 spinturbine rotor is spinningsolid on
 firepropane ignitionsolid on
 accefuel pump startsflashing
 idleturbine idlesolid on
4. Flight Mode Switch: Normal -> Idle Up & Set Collective Pitch to neutral (0 degrees)
 0%++increasing turbine powersolid on
 100%achieved maximum powerturns off
6. Add collective pitch to take off.
Table 3.

Turbine Autostart Procedure - Absent-Coupling

StepConsoleEventAuxillary LED
1. Beginstop  
2. Turbine Safety Switch: ONrun solid on
3. Cycle Turbine RPM Switch: IDLE -> MAX -> IDLE
 rel-system release for startupsolid on
 spinturbine rotor is spinningsolid on
 firepropane ignitionsolid on
 accefuel pump startsflashing
 idleturbine idlesolid on
4. Set Collective Pitch to neutral (0 degrees)
5. Set Turbine RPM Switch: MAX
 0%++increasing turbine powersolid on
 100%achieved maximum powerturns off
6. Add collective pitch to take off.
Table 4.

The turbine safety switch is the only way to start or stop your JAKADOFSKY turbine engine and can be used at any operating speed. The engine will automatically follow the next procedure during shutdown to ensure the engine cools off to a temperature below 80 degrees to avoid damaging internal components.

Turbine Autostop Procedure - Throttle channel & flight mode switch.

StepConsoleEventAuxillary LED
1. Land Helicopter
2. Flight Mode Switch: Idle Up -> Normal
 100%- -decreasing turbine powersolid on
 idleturbine at idlesolid on
3. Turbine Safety Switch: OFFofffuel valve closingturns off
 offengine cycles during coolingoff
 coolengine below 80 degreesoff
4. Reconnect the data console to retrieve flight statistics.
Table 5.

Turbine Autostop Procedure - Absent-Coupling

StepConsoleEventAuxillary LED
1. Land Helicopter
2. Turbine RPM Switch: MAX -> IDLE
 100%- -decreasing turbine powersolid on
 idleturbine at idlesolid on
3. Turbine Safety Switch: OFFofffuel valve closingturns off
 offengine cycles during coolingoff
 coolengine below 80 degreesoff
4. Reconnect the data console to retrieve flight statistics.
Table 6.