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Helicopters construction
The purpose of this page is to teach you how to build your own helicopters or modify existing ones.
To achieve this objective you need to use:
- a plain text editor such as Plain Text Editor, TextEdit or any other text editor able to save plain text files.
- a 3D modeler compatible with the 3DMF format such as Carrara, Cheetah3D, Meshwork or any other 3D modeler able to save 3DMF files.
- a sound editor such as Amadeus, Audacity, Sound Studio, Sound Edit or any other sound editor able to save sound files.
An helicopter is made up of an "Helicopter configuration.txt" file, one or more 3DMF files, a sound file and a "Credits.txt" file:
- the "Helicopter configuration.txt" file contains the configuration of the helicopter; it can be created or modified with a plain text editor.
- the 3DMF files contain the 3D model of the helicopter; they can be created or modified with a 3D modeler.
- the sound file contains the engine sound of the helicopter; it can be created or modified with a sound editor.
- the "Credits.txt" file contains the credits to the author of the helicopter; it can be created or modified with a plain text editor.
To build a new helicopter you can:
- start from an existing ready to fly helicopter from our library and modify its "Helicopter configuration.txt", 3DMF, sound and "Credits.txt" files; this is the easiest way of doing.
- start from an existing draft helicopter from our library and modify its "Helicopter configuration.txt", 3DMF, sound and "Credits.txt" files; this is a way of doing a bit less easy.
- start from scratch and create the "Helicopter configuration.txt", 3DMF, sound and "Credits.txt" files from scratch; this is the less easy way of doing.
How to build or modify an existing "Helicopter configuration.txt" file?
To achieve this objective you need to use a plain text editor such as Plain Text Editor, TextEdit or any other text editor able to save plain text files.
If you want to modify an existing ready to fly helicopter, open its "Helicopter configuration.txt" file with your plain text editor.
If you want to modify an existing draft helicopter, open its "Helicopter configuration.txt" file with your plain text editor.
If you want to create an helicopter from scratch, open a blank page with your plain text editor.
Before creating or modifying an "Helicopter configuration.txt" file we suggest you to open an existing one to see how it is done. An application such as Plain Text Editor or TextEdit allows you to do so.
The file contains the configuration of the helicopter.
The HELICOPTER_NAME variable defines the name of the helicopter. It should be equal to the folder which contains the "Helicopter configuration.txt" file.
The HELICOPTER_VERSION variable defines the version of the helicopter. It must be increased each time a new version of the helicopter is released.
The BODY_PART_i_STATE_j_FILE_NAME variables define the names of the 3DMF files which contain the 3D model of the helicopter.
The BODY_PART_i_STATE_j_DURATION variables define the durations of each state (in seconds).
The ENGINE_SOUND_FILE_NAME variable defines the name of the sound file which contains the sound of the helicopter.
The CENTER_OF_GRAVITY_HEIGHT variable defines the center of gravity height of the helicopter (in meters). It must be exactly equal to the center of gravity height you have chosen in the 3DMF helicopter file; which means your helicopter lays in the (X, -CENTER_OF_GRAVITY_HEIGHT, Z) plane.
The MASS variable defines the mass of the helicopter (in kilograms). It is the real mass of the real RC model you want to reproduce.
The MAIN_ROTOR_UNITARY_ABSOLUTE_LIFT variable defines the absolute lift of the main rotor (in newtons) for a unitary movement of the main rotor throttle and pitch stick of the transmitter.
The MAIN_ROTOR_AIRSPEED_LIFT variable defines the airspeed lift of the helicopter (in kilograms*seconds^-1).
The BODY_UNITARY_TILT_SPEED variable defines the speed at which the body of the helicopter tilts (in radians*seconds^-1) for a unitary movement of the main rotor tilt sticks of the transmitter.
The TAIL_UNITARY_ROTATION_SPEED variable defines the speed at which the tail of the helicopter rotates (in radians*seconds^-1) for a unitary movement of the tail rotor pitch stick of the transmitter.
The BODY_TRANSLATION_FRICTION_COEFFICIENT variable defines the translation friction coefficient of the helicopter (in seconds*meters^-2).
The TAIL_ROTATION_FRICTION_COEFFICIENT variable defines the rotation friction coefficient of the helicopter about its main rotor axis (in radians*meters^-1).
The BACK_FACES_RENDERING variable defines if the back faces of the helicopter are rendered (as boolean).
The example below shows you a typical "Helicopter configuration.txt" file:
#################################
# Helicopter Configuration File #
#################################
# Helicopter name
HELICOPTER_NAME = Hughes
# Helicopter version
HELICOPTER_VERSION = 3.0
# Body parts states file names and duration (in seconds)
BODY_PART_1_STATE_1_FILE_NAME = Hughes.3dmf
BODY_PART_1_STATE_1_DURATION = 0
#Engine sound file name
ENGINE_SOUND_FILE_NAME = Turbine.wav
# Center of gravity height (in meters)
CENTER_OF_GRAVITY_HEIGHT = 0.14
# Mass (in kilograms)
MASS = 2
# Main rotor unitary absolute lift (in newtons)
MAIN_ROTOR_UNITARY_ABSOLUTE_LIFT = 0.5
# Main rotor airspeed lift (in kilograms*seconds^-1)
MAIN_ROTOR_AIRSPEED_LIFT = 10
# Body unitary tilt speed (in radians*seconds^-1)
BODY_UNITARY_TILT_SPEED = 0.05
# Tail unitary rotation speed (in radians*seconds^-1)
TAIL_UNITARY_ROTATION_SPEED = 0.1
# Body translation friction coefficient (in seconds*meters^-2)
BODY_TRANSLATION_FRICTION_COEFFICIENT = 0.02
# Tail rotation friction coefficient (in radians*meters^-1)
TAIL_ROTATION_FRICTION_COEFFICIENT = 0.005
# Back faces rendering (as boolean)
BACK_FACES_RENDERING = False
How to build or modify an existing 3DMF file?
To achieve this objective you need to use a 3D modeler compatible with the 3DMF format such as Carrara, Cheetah3D, Meshwork or any other 3D modeler able to save 3DMF files.
If you want to modify an existing ready to fly helicopter, open its 3DMF file with your 3D modeler.
If you want to modify an existing draft helicopter, open its 3DMF, 3DS, DXF or mesh file with your 3D modeler. The 3D model was saved in these different 3D formats so that you can open the one you want with your 3D modeler.
If you want to create an helicopter from scratch, open a blank page with your 3D modeler.
Before creating or modifying a 3DMF file we suggest you to open an existing one to see how it is done. An application such as 3DMF Viewer or any other 3D viewer allows you to do so.
The helicopter must be scaled to that it has the size of a RC reduced model, and if possible the real size of the real RC model you want to reproduce.
The horizontal plane is the (X, Z) plane and the up vertical direction is the Y direction.
The coordinates of your 3D model must be in meters.
The helicopter must face the Z direction.
The helicopter must be placed in the 3D modeler so that the origin of the axes (0, 0, 0) are at the center of gravity of the helicopter.
The example below shows you a 3DMF file that you can build, which is an helicopter in the (X, Z) horizontal plane, it faces the Z direction, and its up direction is the Y direction. Its center of gravity height is 14 centimeters so it lays in the (X, -0.14, Z) plane.
Helicopters are a bit difficult to build because their 3D model is a bit complex due to a quite high number of 3D points and 3D faces.
We suggest you to start with draft helicopters, to correct their scale, to correct their direction and to correct their faces in a first time.
Then you only need to map the helicopter with a texture with your 3D modeler and then save the model as a 3DMF file. That's all.
How to build or modify an existing sound file?
To achieve this objective you need to use a sound editor such as Amadeus, Audacity, Sound Studio, Sound Edit or any other sound editor able to save sound files.
If you want to modify an existing ready to fly helicopter, open its sound file with your sound editor.
If you want to modify an existing draft helicopter, open its sound file with your sound editor.
If you want to create an helicopter from scratch, open a blank page with your sound editor.
Before creating or modifying a sound file we suggest you to open an existing one to see how it is done. An application such as QuickTime Player or any other sound player allows you to do so.
The sound must be the engine sound of a RC reduced model, and if possible the real engine sound of the real RC model you want to reproduce.
The sound must last at least 10 seconds.
How to build or modify an existing "Credits.txt" file?
To achieve this objective you need to use a plain text editor such as Plain Text Editor, TextEdit or any other text editor able to save plain text files.
If you want to modify an existing ready to fly helicopter, open its "Credits.txt" file with your plain text editor.
If you want to modify an existing draft helicopter, open its "Credits.txt" file with your plain text editor.
If you want to create an helicopter from scratch, open a blank page with your plain text editor.
Before creating or modifying a "Credits.txt" file we suggest you to open an existing one to see how it is done. An application such as Plain Text Editor or TextEdit allows you to do so.
The file contains the credits to the author of the helicopter.
The Package field contains the name of the helicopter. It should be equal to the folder which contains the "Credits.txt" file.
The Author field contains the name of the author of the helicopter.
The Email field contains the email of the author of the helicopter.
The text contains the credits to the author of the helicopter.
The example below shows you a typical "Credits.txt" file:
Package : Hughes
Author : Pascal CHIOTASSO
Email : pascalchiotasso @ yahoo . fr
This package and any of the files it contains are for private use only and are not
in the public domain.
You are not allowed to publish, offer, resell or distribute this package and any
of the files it contains in any form, via the internet, via CD/DVD or via any
other mean without explicit and written permission from the author.
At the moment, the only authorized source for this package is
http://www.alphamacsoftware.com.
Please contact the author for any questions you may have about this package and
the files it contains.
How to use your helicopter?
To use your helicopter in the simulator you just have to name the 3DMF file and the sound file coherently with the content of the "Helicopter configuration.txt" file and the "Credits.txt" file.
Put these 4 files into a folder named coherently with the content of the "Helicopter configuration.txt" file and the "Credits.txt" file.
Put this folder into the "Helicopters" folder of the simulator.
Select this helicopter in the simulator.
You can send us the helicopters you've created if you want us to add them in our online library of ready to fly helicopters. This way all users can share the helicopters they have created.
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