WIP Pander D model 1924

[Frans.Hessels]

Hello Fusionistas,

In response to show some of the project we, a group of enthusiastic volunteers in the Netherlands are working on I started this topic.

We are planning to build a replica of a small airplane from the year 1924 called Pander type D. Wing span 8.00 m, Fuselage length 4.95 m.

A while ago the historical research began and using the collected data it is my task to make drawings from it.

The workflow is as follows:

- In Illustrator I made sketches scale 1:1 from the only photograph in existence of wing rib #3.

- Next all 10 ribs were drawn in Illustrator using the collected information.

- Next I drew a rectangle around every rib positioned at the same distance and angle from the highest rib point and of the same size. The highest point of every rib line up with each other.

- After this the rib drawings were saved as separate pdf files and in Photoshop saved as jpg, quality 12, 150 dpi.

- In Fusion 360 I saved the first file as WingRib2, having the largest contour.

- Using Attached Canvas the first WingRib2.jpg was placed, horizontally flipped and calibrated. The center of the wing spars are 750 mm apart.

- Using Spline and Line I drew the contour so in the copy's of the component the contours would have the same amount of vertexes.

- The file was saved and saved as copy to create a set of wing rib files.

- At the end I saved a new file giving it the name Wing and inserted all the other files in it.

The result so far is shown here.

There is more to come in the future. Hope you like this WIP.

Frans Hessels

[Frans.Hessels]

Next step: scaling and pulling all contour splines and lines in place.

[davebYYPCU]

Fusion splines?

If imported splines, Fusion will choke.

Far too many spline points, sending PM.

[Frans.Hessels]

Hello Dave,

the splines are all Fusion splines. I will remove some spline points and see if the overall contour stays intact. New to Fusion I don't know the limitations of this software so feel free to let me know if there will be obstacles. Goal of this all is to build a real plane, not a RC or scale model.

Thanks for your PM. I will send you mine.

[TrippyLighting]

No, you don't really need to remove just "some" spline points. You can remove 70%-80% of them and work with the spline tangency handles to get to the shape you need.

I bet the you can approximate the shape well enough with 4-5 spline points in each case.

You also have way too many profiles for that loft to result in a nice even surface.

Less is more in this case.

It is a common misconception propagated by terribly uniformed youtube tutorials that NURBS surfaces are created  by using the same data that is used to physically build planes, wings, boats etc.

[davebYYPCU]

Model Aircraft are real aircraft, just smaller, with different materials and construction techniques, but the shapes are the same.  

What Peter has said is 100% correct, from outside > in is easier to be accurate, you have already said you have scarce documentation/s, accurate skin, will make all the ribs accurate, 

not accurate ribs will make a bad skin.

Happy to help....

[etfrench]

What do the curvature combs look like for each rib? (Right click on the spline and select 'Toggle Curvature Display')

[Frans.Hessels]

Hello all,

to avoid misunderstandings, we plan to build the real thing. Scale 1:1. Why building it from the inside > out. There is no outside to begin with that is accurate enough for our goal.

Yes we do need all the ribs because they will be made the old-fashioned way by hand. The ribs are all nicely lined up so no worry about the skin envelope.

No laser cutting and CAM but spruce and plywood cut by hand and plywood glued in layers like it was done back in 1924 by the people of the Pander factory. All under the watch full eyes and guidance of professionals from the aircraft industry.

It will be a historical journey building the replica('s) as good as possible like they did it almost a century ago.

Fusion splines differ from the ones I am used to in Illustrator and Autocad. Illustrator splines can be manipulated on each side of the vertex in angel and distance and radius. Fusion splines work with tension equal on both sides and just one angle. No problem.

Also Scaling differs from Illustrator. No x and y scaling apart like in Illustrator but only one overall scaling like in Autocad.

There are already 3d models on the internet showing a Pander type D and there is a RC model you can buy. They are not ours.

Thanks for all the advice, some of which I follow and feel free to make your remarks.

All though I am working with Autocad from 1986 on, Fusion is new for me and I am curious where its boundary's lay.

Best regards and enjoy the WIP,

Frans.

[Frans.Hessels]

Hello etfrench,

I have seen the tutorial at Lars Live about the curvature combs but for this project they are of no use. So sorry I can't show you.

Best regards,

Frans

[etfrench]

That's odd.  The curvature comb will show you if the control points of your splines create fair curves.  Toggling them on or off doesn't affect the model.

[TrippyLighting]

---

@Frans.Hessels wrote:

Hello etfrench,

.. but for this project they are of no use...

---

Wrong!

Granted, for the sake of the physically build end product,  you don't need perfect curvature. There is going to be plenty of hand work and hand sanding involved in re-creating that plane, so trying to get a class A surface (class A is a technical term relating to G1,2,3,4 surface continuity) is not of much use.

However, as your work will be based on a CAD model you have to complete that first before you can proceed with that physical build. I can tell you from ample experience that when you try to work with crappy surfaces created by using too many spline points, to many rails and profiles Fusion 360 will choke on it and you will not even be able to complete the model.

As to your earlier comment that you needle these ribs. Yes, of course you do. For the physical build, but not for recreating the model digitally. Here's a little article about the dirty little secrets of on NURBS surfaces that explains some of this.

[Frans.Hessels]

Hello etfrench,

there is no need for a curvature comb because in Illustrator I did my homework and created perfect French curves/splines in the cross section drawings that form the canvases in Fusion. I only have to trace those lines with the Fusion splines to know that they are perfect. 

This is one of the canvases in use:

and this is the result after tracing it in Fusion with a Fusion spline:

and as said before there will be less vertexes in the splines at short notice.

Best regards,

Frans

[Frans.Hessels]

Hello Peter,

this is a photo from the internet showing the airplane that we are planning to build. 

No mesh above and under the wing so no loft ore mesh ore polysurface has to be drawn there.

From previous reactions at forums I know you are a strong believer of splines with a minimum of points.

So ones again, yes there will be fewer points in the splines at short notice.

Best regards,

Frans.

[TrippyLighting]

Ahhh... Now I get it. I totally misunderstood what you were going for. Yes, that'll work of course and in that case there is not need to obsess about curvature.

This is quite a nicely shaped plane. I'd love to see images of the real thing as you go along building it.

[Frans.Hessels]

Here is the result after reducing the spline points and at every rib the contour is offset inwards 5 mm.

to reduce the spline points a followed the next procedure:

- offset the heavy pointed contour inwards. Fusion gives a spline showing only the end points from every spline and line.

- delete the heavy pointed contour

- offset the new created spline to the original position of the former point heavy spline and end up with (in this case) two splines with each only three points.

[TrippyLighting]

Nice!