JSBSim Piper J-3 Cub

[wlbragg]

According to what I've read the tail wheel wasn't removed when the nose wheel was installed.

Interesting, you can see the tail wheel is still installed in the one older image. Yet some of the more modern images it's removed, although the newer images may not be a J3Cub.
I removed the tail gear and its weight to help get the balance right. I'm not sure it will work if I add the weight back to the tail.
I'll try it again now that I have the contacts and weight adjustment finalized and see whet happens. Maybe I can give the option to include it or not.

[wlbragg]

Maybe I can give the option to include it or not.

Done, now there is the option to include it or not. It does change the cog slightly if selected or not.

Speaking of cog, it is rather interesting in the j3-tricycle configuration, 180 lb pilot in the back seat, fuel tanks on fumes and max luggage in the back, cog is somewhere around 20" which is barely in front of the back wheels. It still flies nice though.

And yes, I noticed a huge improvement in ground handling in the tricycle configuration. A bit of rudder control and your right down the middle.

[wlbragg]

For anyone not watching commits to fgaddon, there has been a few new additions to the Cub.

A new gear configuration (Tricycle trainer).
ga-it-autopilot, thanks Josh (still needs some tuning and we would appreciate any feedback on it).
New simulated heat vent visual on the windshield for frost and fog.
To help with the frost and fog and cabin temperature management a selectable indoor/outdoor temperature gauge.

A few top TODO items...
- ai gauge
- front wheel castering setup with a spring loader
- full electrical system including panel lighting
- everything and anything multi-player related
- model PA-18 fuel system

[Octal450]

I can do the tuning, if you want.

Enjoy
J

[wlbragg]

I can do the tuning, if you want.

That would be great, I just synced GitHub with fgaddon so it is ready.

[Octal450]

Great.

[Octal450]

Done, Bugfix 1 Applied.

[wlbragg]

Added to fgaddon, thank you!

Does the AP not being able to be engaged on the ground a normal feature of and AP? If so, how does a "real" AP know if it is sitting on the ground?

[Octal450]

Hmm, that must still be in from the aileron IT-AUTOFLIGHT. I will add it as an optional thing in Build 2.

BTW, most updates to the AP just require dropping in the new files, and overwriting, see the CHANGELOG to know if anything needs to be updated.

You may want to take a look at this: http://wiki.flightgear.org/IT-AUTOFLIGHT/GA#settings

Kind Regards,
Josh

[Octal450]

@wlbragg

How do you want updates to work? I can push them to the GitHub if you want, or you can update it yourself? What is your option?

I've just pushed Build 2 which is PID Controller Update.

[wlbragg]

ow do you want updates to work? I can push them to the GitHub if you want

I would prefer you do it and just nudge me when you do in case I don't check the repo often, thanks.

[Octal450]

OK

Kind Regards,
Josh

[Octal450]

Updated

Kind Regards,
Josh

PS: still stays off on the ground, didn't find time to change it yet. Expect in Build 4.

[helikiwi]

Wow what a great aircraft

Is there a way off increasing the payload for spraying from 300lb to 750lb?

Thanks
Brett

[wlbragg]

Hi Brett,

The simple answer is yes.
In the file J3Cub/J3Cub-main.xml Starting at line 569

Code: Select all

        <weight>
            <name type="string">Hopper</name>
            <weight-lb alias="/fdm/jsbsim/inertia/pointmass-weight-lbs[15]"/>
            <arm-in alias="/fdm/jsbsim/inertia/pointmass-location-X-inches[15]"/>
            <min-lb type="double">0.0</min-lb>
            <!--max-lb type="double">300.0</max-lb-->
            <max-lb type="double">750.0</max-lb>
        </weight>

Above I comment out the 300.0 lb limit and change it to 750. I'm not sure if there is some nasal or other code that might initialize it to 300 lbs and override the 750 lbs at times, but you should be able to change it as above, just keep in mind it may get changed at times by other code. I really am not sure if it will or not.

Now my question to you is, why? This will undoubtedly cause a gross overload. Do you know if there was a tank this large installed in these aircraft? I don't remember exactly how I came up with this weight, but I'm sure there was some logic to it. If you have some historical information that pertains to this I would love to hear it and would consider potentially making this a permanent choice.