Like many contemporary designs, the SBD had a long, segmented (“greenhouse”) cockpit canopy. In this post I will show you how I recreated it in my model. I will begin with pilot’s canopy, then continue by creating the three next transparent segments.
I formed the pilot’s canopy by extruding the windscreen rear edge (Figure 50‑1). (I formed this windscreen earlier, it is described in this post). The high-resolution reference photo was a significant help in precise determining its size and shape:
Generally, the canopy shape in the SBD is quite simple. The tricky part was that each of its segments slides into the previous one. (Oh, well, the pilot’s canopy slides to the rear, but it does not matter in this case). This means that there were clearances between each pair of neighbor canopies that permitted such movements. If I made them too small or too wide, the last (fourth) canopy segment would not fit into cockpit rear border (i.e. the first tail bulkhead)! In such a case I would have to adjust back all the canopy segments. Well, I will do my best to avoid such error.
After the pilot’s cockpit canopy I created the next, fixed segment (Figure 50‑2):
It was a fixed part of the cockpit canopy, bolted to the fuselage. I used the available reference photos to precisely recreate its shape. Of course, I also had to determine the distance between the sliding pilot’s canopy and this segment. It was a key moment: making it too narrow or too wide would spoil all further segments.
The photo references can be useful even when the modeled object is not visible: you can see such a case in Figure 50‑3:
Although in the reference photo the gunner’s canopy is hidden under the fixed segment, the last canopy element is in place. Thus I used its forward edge as the reference shape for the rear edge of the previous canopy. The front edge of this element is deduced from the cross section of the previous canopy segment, offset inside by the clearance distance.
Initially I created the last canopy segment by extruding such an “offset” rear edge of gunner’s canopy (Figure 50‑4):
The initial evaluation of the cockpit rear edge revealed that I had to extend a little the last edge of this object, to match the shape visible in the photos (Figure 50‑5):
Of course, I also had to take care about the clearance between this and the previous canopy segment (Figure 50‑6a):
In the next step I cut out the unnecessary part of this mesh (Figure 50‑6b).
Finally I recreated the rounded corner of this segment. I did it using an additional vertex, located on the bottom edge of the last mesh face. (See Figure 50‑7. In this way that face becomes an n-gon). When I slide this vertex forward along the bottom edge, it reduces the radius of this corner. A movement into opposite direction enlarges it:
Figure 50‑8 shows the complete cockpit canopy. Fortunately, its last segment fits well into the cockpit rear edge (Figure 50‑8), so I do not have to adjust all these canopy segments! (I mentioned such a possibility at the beginning of this post).
In this source *.blend file you can evaluate yourself the model from the figure above.
The shapes you can see in red in Figure 50‑8 will become the transparent plexiglass surface. I still have to place the sheet metal frames on these elements (I will do it in the next post). There were also internal tubular structures that supported these canopies from inside. I will recreate them during the last, detailing phase of this project.
2 thoughts on “Forming the Cockpit Canopy”