Modeling Bottom Fuselage (2)

Sometimes the relatively simple shapes may require some substantial amount of work. In the previous post I created the basic shape of the bottom fuselage. It occurred quite complicated, because I decided to recreate the opening of the bomb bay “in the mesh”, instead of using the Boolean modifier. In this post I will complete the remaining details, enlisted in Figure 28‑1:

Figure 28‑1 The details on the bottom of the SBD fuselage that I will recreate in this post

I started by forming the bottom part of the fairing along the wing leading edge. It is not as difficult as the upper fairing. To show you the basic idea I just added a new edge loop near the firewall, then I moved down the corner vertex downward. As you can see below, the resulting surface starts to wrap around the wing (Figure 28‑2):

Figure 28-2 Beginning of the wing root fairing

Then I added another edge loop, adjusted locations of some vertices, and extruded fragment of this mesh in the spanwise direction (Figure 28‑3):

Figure 28-3 Finished wing root fairing

As you can see in the figure above (left) I hid the upper edge of this fairing below the lower edge of the upper fuselage panel. (You can see these overlapping panels on the close-up photos of the real aircraft).

When I finished the wing root fairing, I recreated the bottom covers. I started each cover by copying the border edges from the adjacent meshes (Figure 28‑4a):

Figure 28-4 Forming the bottom cover

Then I adjusted these edges, matching the number of corresponding vertices. Once they were ready, I connected them with the strip of new faces (Figure 28‑4b).

However, this cover was not completely flat! To fit it to the side view contour (and the reference shape) I inserted a new edgeloop in the middle of this mesh. Then I adjusted its height, fitting it to the contour of the fuselage (Figure 28‑5):

Figure 28-5 Fitting the bottom cover to the reference shape

These removable covers were bolted to the flanges that extrude from the bomb bay edges. To obtain a better fit, these mounting flanges were stamped by the sheet metal thickness (as in see Figure 28‑6a):

Figure 28-6 Cover mounting flanges around the opening

How do I form such a “depressed” flange? I started by extruding its borders (Figure 28‑6b).  Then I connected these faces into a single strip (Figure 28‑7a). Finally I extruded these faces (not edges!) along their individual normals (I shifted the extruded faces using the Shrink/Fatten command) (Figure 28‑7b):

Figure 28-7 Forming the mounting flanges

Finally I marked the outer edge in the control mesh as partially sharp (Figure 28‑7c) to improve the profile of this flange.

Figure 28‑8a) shows the layout of the newly created cover panels. After all these modifications it is good idea to match this result against the available photos. As it often happens, I discovered that I should do it more often: there were some errors in this initial arrangement:

Figure 28-8 Corrections that I made to the panels layout

Well, in fact I had to rebuild anew the side doors and the rear cover (repeating all the tasks depicted between Figure 28‑4 and Figure 28‑7). You can see the final result in Figure 28‑8b).

Note that I slightly reduced the width (i.e. radius) of the rear cover. I decided that I was wrong estimating its size in the previous post (see Figure 27‑4). This time my reference drawing was right (Figure 28‑9):

Figure 28-9 Finished bottom fuselage (at least for the modeling stage)

Figure 28‑9 shows the completed bottom part of the fuselage (I hid the removable covers). As you can see, there still are many small details that I have to recreate during the detailing stage.

In this source *.blend file you can evaluate yourself the model presented in the picture above.

The issue that I had with the bottom covers shows that I should do such a verification from time to time! In the next post I will “step back” a little and match the overall shape of this model against the photos. I will do it using a new method.

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