Help on designing Fuselage
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- Posts: 7
- Joined: Wed Jul 23, 2014 8:24 am
Help on designing Fuselage
Hi all,
I'm trying to use FreeCAD to design some Airplane model. FreeCAD is a very interesting tool. It help me to save a lot of time to design a Wing. Now, I have some problem in designing a Fuselage. I had tried to use Loft, Sweep but I haven't got exactly the model I wanted.
I draw some circles and loft them but the surface isn't smooth. Is there any tool in FreeCAD help me to design a simple fuselage.
Because I'm newbie in CAD, I hope to get some advice.
Thanks for any help!
Leo
I'm trying to use FreeCAD to design some Airplane model. FreeCAD is a very interesting tool. It help me to save a lot of time to design a Wing. Now, I have some problem in designing a Fuselage. I had tried to use Loft, Sweep but I haven't got exactly the model I wanted.
I draw some circles and loft them but the surface isn't smooth. Is there any tool in FreeCAD help me to design a simple fuselage.
Because I'm newbie in CAD, I hope to get some advice.
Thanks for any help!
Leo
- Attachments
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- fuselage2608.FCStd
- Fuselage
- (43.95 KiB) Downloaded 329 times
Last edited by pinkbigpig on Fri Aug 29, 2014 6:39 am, edited 1 time in total.
Re: Help on designing Fuselage
Hello Leo,
Welcome here.
You thave way too many sections. The loft has to pass through everyone of them, which makes for a rough surface. You need to reduce the number of sections, there should only be a bare minimum. Also, your sections do not follow exactly the contour of the plane (the "Wire" object) which creates those bumps.
Welcome here.
You thave way too many sections. The loft has to pass through everyone of them, which makes for a rough surface. You need to reduce the number of sections, there should only be a bare minimum. Also, your sections do not follow exactly the contour of the plane (the "Wire" object) which creates those bumps.
Re: Help on designing Fuselage
You can also make a series of Lofts rather than a single one. Here's an example using a limited number of your existing sketches. I fused them together with the Part Fuse (Union) tool.
- Attachments
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- fuselage2608_normandc1.FCStd
- (48.81 KiB) Downloaded 343 times
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Re: Help on designing Fuselage
Thank Normandc! It's helpful for me.
I want my model follow exactly the contour, so I draw a lot of circles. And now I know it's not a good idea. Thanks again!
Leo
I want my model follow exactly the contour, so I draw a lot of circles. And now I know it's not a good idea. Thanks again!
Leo
Re: Help on designing Fuselage
I generally begin with cross sections in the same positions that they were on the real aircraft.
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- Posts: 7
- Joined: Wed Jul 23, 2014 8:24 am
Re: Help on designing Fuselage
Hi,
I try some models and I have some questions here.
How can I get this object

instead of this in FreeCAD?

Thank you for any advice!
Leo
I try some models and I have some questions here.
How can I get this object
instead of this in FreeCAD?
Thank you for any advice!
Leo
- Attachments
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- fuselage_with_xflr5_Loft.FCStd
- (12.6 KiB) Downloaded 211 times
Re: Help on designing Fuselage
Your images are not showing...however if you change the very last digit in you url from 0 to 1, it seems to work. Like this

and

Jim
Code: Select all
[img]https://www.dropbox.com/s/9o9kgbw3373kpfs/fuselage_xflr5.PNG?dl=1[/img]
and
Code: Select all
[img]https://www.dropbox.com/s/oyvv716e25jf1up/fuselage_freecad.PNG?dl=1[/img]
Jim
Re: Help on designing Fuselage
in answer to your question....it will be more complex than just this but start by toggling "ruled" property of the Loft...assuming that you did a single multi profile Loft and not several different Lots fused together.
Also If your shape is symmetric about any axis, you might consider making a cross section either in sketcher or Draft if you need splines and then rotating it with either the PartDesign or the Part wb rotation tools.
Also If your shape is symmetric about any axis, you might consider making a cross section either in sketcher or Draft if you need splines and then rotating it with either the PartDesign or the Part wb rotation tools.
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- Posts: 7
- Joined: Wed Jul 23, 2014 8:24 am
Re: Help on designing Fuselage
Hi vrytar, thank you for your advice.vrytar wrote:I generally begin with cross sections in the same positions that they were on the real aircraft.
Can you give me some example or some information to make it clear?
Hi jmaustpc, I'm sorry about my mistake.jmaustpc wrote:in answer to your question....it will be more complex than just this but start by toggling "ruled" property of the Loft...assuming that you did a single multi profile Loft and not several different Lots fused together.
Also If your shape is symmetric about any axis, you might consider making a cross section either in sketcher or Draft if you need splines and then rotating it with either the PartDesign or the Part wb rotation tools.
I know it will be more complex than I did, so I really want to receive your advice. I try to find a way to design a simple fuselage in FreeCAD , which is not symmetric.
Leo
Re: Help on designing Fuselage
Not sure how well this works for modern planes, but historic aircraft was essentially made by lofting from a few sections. You can see the shapes and positions of the sections in any decent plan.
http://www.fiatcr32.rotorswings.com.au/
I try to create the sections shown in the plan as closely as possible and put them in the right positions. Then I hope the FreeCAD loft function will do pretty much the same thing as real life lofting in the factory. If this doesn't work, I tweak the model, but at least I have a starting point.
http://www.fiatcr32.rotorswings.com.au/
I try to create the sections shown in the plan as closely as possible and put them in the right positions. Then I hope the FreeCAD loft function will do pretty much the same thing as real life lofting in the factory. If this doesn't work, I tweak the model, but at least I have a starting point.