I also added the first part of the gear configurations (bush wheels). This is jutt the initial step, I don't even know for sure what size they were or if I am going to change them to a different size. I need to research and come up with a commonly used size. Unlike the c172p I plan to use only one bush tire size and not two.
There are many, many pieces to add the gear configurations including FDM weight and drag data points. Those data points are not included in the existing FDM structure yet. They will need to be verified and adjusted to match the Cub's version of weights and drag. For example, in Systems/bushkit.xml the data variable produced when switching to the bush gear (currently called 36" even though I don't know that that was the size I made them, I just copied over what i had in the bush version of the Cub) is gear/drag-coef[1]. This additional drag still needs to be added to the FDM at the appropriate place.
This is an example of how we added it in the c172p
- Code: Select all
<axis name="DRAG">
<function name="aero/coefficient/CDo">
<description>Drag_at_zero_lift</description>
<product>
<property>aero/qbar-psf</property>
<property>metrics/Sw-sqft</property>
<value>0.027</value>
<property>gear/drag-coef[1]</property> <!-- bush wheels 26" -->
<property>gear/drag-coef[2]</property> <!-- bush wheels 36" -->
<property>gear/drag-coef[3]</property> <!-- Floats -->
<property>gear/drag-coef[4]</property> <!-- Amphibious -->
<property>gear/drag-coef[5]</property> <!-- Ski -->
</product>
</function>
Note: In the J3Cub there will only be
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<property>gear/drag-coef[1]</property> <!-- bush wheels 36" -->
<property>gear/drag-coef[2]</property> <!-- Floats -->
<property>gear/drag-coef[3]</property> <!-- Amphibious -->
<property>gear/drag-coef[4]</property> <!-- Ski -->
The weight for each wheel is also produced in Systems/bushkit.xml.
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<channel name="extra-weight">
<switch name="extra-weight-left-36-in">
<default value="0"/>
<test logic="AND" value="15">
bushkit EQ 1
</test>
<output>/fdm/jsbsim/inertia/pointmass-weight-lbs[5]</output>
</switch>