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B-52H Build Thread

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B-52H Build Thread

Postby JetFuelSuitcase » Tue Aug 13, 2019 1:51 am

Here's the original announcement post:
viewtopic.php?f=4&t=36196

I'll try and post updates on here as often as I can, and you see anything I should do better, post a reply.


It'll probably be moving along at a snail's pace due to school workload, but here's what I've gotten done so far;

.xml files
Direct
TF33-P-3
panel.xml
interior.xml
b52h.xml
b52hAero
b52-set

Models
b52h.3ds
cockpit.3ds
panel.3ds

I am having some trouble getting the aircraft to show up in the Flightgear 'installed aircraft section'. It might be an issue with a file, I'm not sure. I'll try launching it from the command line. I can upload the files if anyone would like to help.
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Re: B-52H Build Thread

Postby Octal450 » Tue Aug 13, 2019 1:56 am

Hi JFS,
If the aircraft does not show up, probably because:
- the syntax of -set.xml is bad
- -set doesn't have .xml extension
- not enough tags inside.

See here: http://wiki.flightgear.org/Aircraft-set.xml

But yes, if you upload the files (I recommend learning GIT and using GitHub) then I'd be happy to look through and let you know what the issue is.

Kind Regards,
Josh
Don't ever contact me about FlightGear again.
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Re: B-52H Build Thread

Postby JetFuelSuitcase » Tue Aug 13, 2019 8:10 pm

Thanks Josh,
Today I'll comb through the -set.xml and see if I can find any issues. I'll also look into uploading the files.
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Re: B-52H Build Thread

Postby Octal450 » Tue Aug 13, 2019 9:32 pm

Sounds good!

Kind Regards,
Josh
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Re: B-52H Build Thread

Postby JetFuelSuitcase » Wed Aug 14, 2019 1:39 am

Today's progress:

I've fixed the -set.xml issues, the syntax was off in a few places (Thanks for the suggestion Josh!). I was able to see it in the launcher, as well as load in to Flightgear, but this is where the issues start.

First, the aircraft starts in cockpit view, except there is no cockpit to be seen. I suspect the camera is inside of the model somewhere, breaking that view. The default 2d panel for the Cessna also is displayed, even though I think I turned it off in the -set.

Second, the model rotates around the very end. I'm thinking this is a simple fix to reposition the centre axis. It also flips upside down under the runway, probably because there is no collision detection as of yet.

Finally, there is an issue with the smooth shading. It might be that some parts of the plane weren't closed by the original modeler, leaving hairline cracks along the vertices. This results in black triangles of the geometry. I tried path smoothing and welding, but neither seemed to work. I'm using Wings3D for the model work at the moment because I don't feel like taking on Blender right now.

I've uploaded all that I have to GitHub, here's the link;
https://github.com/jetfuelsuitcase/Flig ... tofortress

I'm a little embarrassed about how basic it is, I haven't even assigned keybindings yet. This is still my first real foray into programming, but I think I'm learning more about how FG and other programs work by the day.
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Re: B-52H Build Thread

Postby Octal450 » Wed Aug 14, 2019 4:03 am

Hi,
I would immediately use AeromatiC++ instead of the old web Aeromatic - the result is much much better.

In addition - Aeromatic FCS needs to be thrown away it's rubbish. A custom FCS going thru each control surface is better. Here is an example: https://github.com/Octal450/IDG-MD-11/b ... 11-fcs.xml
Of course, it can be simplified but the basics of how it can be done is here.

Lastly, make sure your model is graphically centered. So that, when the entire model is selected the center is 0,0,0 in the 3d.

As for the cockpit not showing, you can try to reposition the view in View -> Adjust View and see if you can load it. The default Cessna 2D can be killed via shift P.

Kind Regards,
Josh
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Re: B-52H Build Thread

Postby legoboyvdlp » Wed Aug 14, 2019 9:08 am

This results in black triangles of the geometry


Could that be normals? See https://all3dp.com/2/blender-recalculat ... explained/
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Re: B-52H Build Thread

Postby JetFuelSuitcase » Wed Aug 14, 2019 5:41 pm

legoboyvdlp wrote in Wed Aug 14, 2019 9:08 am:
This results in black triangles of the geometry


Could that be normals? See https://all3dp.com/2/blender-recalculat ... explained/



Yeah, that's pretty much what it looks like. I'll get to work on using AeromaticC++, re-centering the model, and recalculating the normals. Thanks for the suggestions.
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Re: B-52H Build Thread

Postby J Maverick 16 » Thu Aug 15, 2019 7:09 pm

I've always dreamt of seeing a good B-52 in FlightGear... seems like the wait starts to shorten itself at last!
Hi and welcome JFS, I hope you can make the best out of it ;)
Cheers, Mav
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Using Thrustmaster FCS Flight Pack.
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Re: B-52H Build Thread

Postby cobe571 » Fri Aug 16, 2019 2:35 pm

JetFuelSuitcase wrote: https://forum.flightgear.org/viewtopic.php?f=4&t=36196#p352424
Cobe,
That looks fantastic. Is it on Git? I could try my hand at making a half-decent FDM for it, if you want


No, the 3D model has not yet been uploaded to GIT. I will do it as soon as possible by providing a link.
I'll be very happy to provide my 3D model to create a very good B-52H for FlightGear.
Meanwhile, I produced some screenshots.

Image

Image

Image

Image

Image

Image

Image

Image

Image

Kind regards

P.
"According to the laws of aerodynamics, the bumblebee can't fly either, but the bumblebee doesn't know anything about the laws of aerodynamics, so it goes ahead and flies anyway."
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Re: B-52H Build Thread

Postby JetFuelSuitcase » Fri Aug 16, 2019 4:21 pm

cobe571 wrote in Fri Aug 16, 2019 2:35 pm:
JetFuelSuitcase wrote: https://forum.flightgear.org/viewtopic.php?f=4&t=36196#p352424
Cobe,
That looks fantastic. Is it on Git? I could try my hand at making a half-decent FDM for it, if you want


No, the 3D model has not yet been uploaded to GIT. I will do it as soon as possible by providing a link.
I'll be very happy to provide my 3D model to create a very good B-52H for Flightgear.


That looks amazing. Can't wait to start working on it. It may be a few days before I can actually produce anything though, since I'm sick. I feel like this project is really going somewhere, and I'm thankful for this super helpful community :D
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Re: B-52H Build Thread

Postby cobe571 » Sat Aug 17, 2019 3:04 pm

The interesting part of this aircraft is the layout of the control surfaces. In particular the arrangement of the ailerons is very interesting. I don't know very well in the previous versions, but on B-52H they are in the middle of the internal flaps and the external flaps. As far as I have seen, in the many videos I have examined in the past years, I have found no trace of ailerons on the terminal part of the wing. in fact inside my 3D model I haven't really modeled them.

Image

:) P.
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Re: B-52H Build Thread

Postby Octal450 » Sat Aug 17, 2019 3:10 pm

Quite normal for large aircraft because the farther it is from the center, it makes more force on the wing. That is why many aircraft have outer aileron lockouts at high speed.

Kind Regards,
Josh
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Re: B-52H Build Thread

Postby Alant » Sat Aug 17, 2019 4:53 pm

The B52 uses spoilerons for roll control (fromhttps://en.wikipedia.org/wiki/Spoileron)
quote:-
The B-52 Stratofortress also had spoilers augmenting small ailerons, known as feeler ailerons. These ailerons provided control forces to the pilot. The B-52G has no ailerons. The spoilers, situated inboard and forward of the trailing edge, are used for lateral control at high speeds to prevent excessive wing twist.[4]
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Re: B-52H Build Thread

Postby Johan G » Sun Aug 18, 2019 9:35 pm

Ah! Looking at videos of BUFFs during aerial refueling, it is quite clear where the spoilerons are located.

There seem to be in pairs; One inboard with smaller movements and one outboard.

AIRBOYD - B-52 Stratofortress Refueling Over The United Kingdom (2 min)


They can also bee seen during landing in comparison with the outboard flaps (which does not seem to have any aileron command mixed in whatsoever). I also wonder how much the spoilers can be deployed without saturating the spoilerons.

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