Yakovlev Yak-3

[Chris_G]

Hi,
I needed a test model for the "Sweep on 2 rails" tool I am working on.
This is a Yakovlev Yak-3, a WW2 warbird that looks really beautiful.
I found this plan on the web, and did some inkscape drawing over it :

web_plan.jpg (72.84 KiB) Viewed 4035 times

Then, I have was able to test the "Sweep on 2 rails" to build the surfaces :

Yak-3.gif (687.33 KiB) Viewed 4035 times

Yak-25.jpg (186.2 KiB) Viewed 4035 times

Yak-26.jpg (21.49 KiB) Viewed 4035 times

Yak-3-03.fcstd

(776.58 KiB) Downloaded 159 times

(Attachment needs my "Curves" workbench)

[triplus]

Looking good.

[Kunda1]

Nice!

[regis]

great stuff,
it reminds of my college project when I had to design an aircraft in Inventor.
I was facscinated by the German Messerschmitt Me163 Komet.

[chrisb]

Very impressive, thanks for sharing.

[regis]

Very impressive, thaks for sharing.

Your process is quite interesting, did you import the inskcape drawings, one at a time and manually positioned them? did you have to scale the inscape files?

[Chris_G]

it reminds of my college project when I had to design an aircraft in Inventor.
I was facscinated by the German Messerschmitt Me163 Komet.

Nice plan. Even though the plane is quite ugly ...

Your process is quite interesting, did you import the inskcape drawings, one at a time and manually positioned them? did you have to scale the inscape files?

The first thing I did was to scale the imported image file in inkscape, so I didn't have to bother about that in the following steps.
Then I imported the whole inkscape file in FreeCAD, and did the placement manually or with some python scripting.

[thschrader]

Chris_G, amazing job, really nice!
We should give the YAK-25 shape to the cfd-WB-guys for testing...
Greetings Thomas

[HoWil]

it reminds of my college project when I had to design an aircraft in Inventor.
I was facscinated by the German Messerschmitt Me163 Komet.

Nice plan. Even though the plane is quite ugly ...

Your process is quite interesting, did you import the inskcape drawings, one at a time and manually positioned them? did you have to scale the inscape files?

The first thing I did was to scale the imported image file in inkscape, so I didn't have to bother about that in the following steps.
Then I imported the whole inkscape file in FreeCAD, and did the placement manually or with some python scripting.

Hi Chris_G ,
I am very interested in this... not for creating planes but for creating free-form objects with the help of Inkscape.
Is it possible to get a fast forward tutorial (including Inkscape) of one of the wings or another simple part?
BR,
HoWil

[Chris_G]

Hi Chris_G ,
I am very interested in this... not for creating planes but for creating free-form objects with the help of Inkscape.
Is it possible to get a fast forward tutorial (including Inkscape) of one of the wings or another simple part?
BR,
HoWil

Look at the attached FC file. It has sketches, but it is the same as what you get when importing svg.
There are 2 rails and 3 profiles.
The profiles need to be rotated around their endpoints.
This piece of python does this (select a profile and run) :

Code: Select all

# rotates the selected NURBS edge around its endpoints
ANGLE = 90
s = FreeCADGui.Selection.getSelection()

for so in s:
    for e in so.Shape.Edges:
        c = e.Curve.copy()
        stPt = c.StartPoint
        enPt = c.EndPoint
        pl = FreeCAD.Placement()
        pl.Base = stPt
        vec = enPt.sub(stPt)
        pl.Rotation = FreeCAD.Rotation(vec,ANGLE)
        for i in range(len(c.getPoles())):
            c.setPole(i+1,pl.inverse().multVec(c.getPole(i+1))+stPt)
        obj = FreeCAD.ActiveDocument.addObject("Part::Spline","Profile")
        obj.Shape = c.toShape()

Then select the 2 rails and make a (PartWB) Ruled surface
Select this ruledSurface and the profiles and run "Sweep profile on 2 rails" tool in my WorkBench :

sw2r-1.jpg (31.35 KiB) Viewed 3840 times

You get a point cloud. You can adjust the number of samples, or the displaymode ("wireframe" below).
Then you can run the approximation tool to get the surface :

sw2r-2.jpg (42.73 KiB) Viewed 3840 times

sw2r-3.jpg (34.93 KiB) Viewed 3840 times

Good luck