Modelling a vintage jet aircraft, need help merging/joining/matching srf

[Dave_Borstel]

Hello!

I’m modelling a vintage jet aircraft and it’s going really well. I decided to “rebuild” an old model I made years ago, now I’m seeing improvements.

With the attached model’s fuselage, and especially the nose I’m happy. But I’m having difficulty merging/joining/matching these surfaces. The shape is pretty much spot on. But I can’t seem to get all these surfaces to join while respecting the round intake shape and the round mid-fuselage shape.

Model.3dm (5.1 MB)

[Dave_Borstel]

In case this is of any relevance..
The process I followed:

• Created full circles (Circle) for the nose, the very tail and the mid-fuselage section Circles. Changed degree to 3.
• Made side-view lines between the mid-section circles, changed degree to 3.
• Made side-view short lines at the nose and tail to indicate an angle I wanted, in order to BlendCrv later.
• BlendCrv the mid-section straight lines to the smaller lines at the front and end of the fuselage.
• Joined this blend with the mid-section straight line.
• Sweep2 to make up the mid and rear section.

Then moving to the nose:

• BlendCrv mid-section straight line to angled straight line at nose. Side view top and bottom.
• Extruded these blends.
• BlendCrv top view straight line mid-section to angled straight line at nose.
• NetworkSrf the bottom part of the nose, from the edge of the mid-section to the Circle at the nose. Using the two blends made (lower and right).
• Made a Cutplane where I figured the biggest shape change should be, and Intersected it with the nose part I just made. Then blended this curve to a 90 degree straight line. These two curves now make a cross section.
• Used another NetworkSrf to create the top of the nose.
• Made a “fill” to close the gap.

[Gerard (Gerard Petersen)]

Hi Dave,
You make your life much harder by trying to model all these patches and then try to connect them. Even if it works, you probably have many difficulties getting a fair and smooth end result.
In my vessel ship hull training, I teach modeling single surfaces that are smooth and fair. As I don’t know which aircraft you try to remodel, I have the idea that you have to model the canopy as a separate single surface and then blend that into the fuselage.
A total other modeling strategy is to do the job with Rhino SubD and create a single SubD for the total plane or most part of the total plane. After modeling the overall SubD, you can convert it to Nurbs and add window details etc.

Good luck and enjoy your quest.

Gerard

[Dave_Borstel]

Hallo Gerard, dankjewel!

It’s supposed to resemble a Fokker S.14 Machtrainer.

Maybe I can try to get the model down to a few cross-sectional curves and only Sweep2. However, many aircraft have compound curves and many complex connections that I see no other way than to build up from separate surfaces. I see they do the same a lot with cars and I’ve watched countless hours of tutorial but I keep bumping my head into the problem described..

[Dave_Borstel]

By the way, the layer Canopy was only added to show the general picture and it’s not my main issue now. The layer Canopy basically covers an “ugly” bridge part that would be trimmed off later to create a solid.

[Gerard (Gerard Petersen)]

Goedemiddag Dave,

Nice to see that you try to model a good old Fokker aircraft.
For me the Loft command is favorable over the Sweep2 command in order to get a surface with a minimum amount of control points.
In the attached example, I modeled an idea of the fuselage with Loft/Loose command in combination with record history (option at the bottom of your Rhino screen). The loft curves are circles that you can move and transform in order to get the desired shape.
Model-RhinoCentre.3dm (1.8 MB)