Mapping Images onto the 3D Model Surface (1)

Because of the holiday break, during July and August I will report my progress every two weeks. I will return to weekly reporting in September.

I have just begun the third stage of this project: “painting” the model. At this moment I am unwrapping its meshes in the UV space . I will deliver you a full post about this process next Sunday. Today I will just signalize how it looks like.

So I started by creating a new reference picture. It had to have a rectangular shape. Inside I placed my drawings of the fuselage, wings, and the tailplane (Figure 60‑1):

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Figure 60-1 Reference drawings for the UV map

Continue reading Mapping Images onto the 3D Model Surface (1)

A New Book — and New Fixes in the Model

Last week I found a new edition of Bert Kinzey’s “SBD Dauntless” book (Figure 59‑1). After ten years break, Bert started to continue his “Detail & Scale” series, this time in a different form: digital editions. This e-book is the “updated and revised” version of an earlier publication (from 1995). For me, the most important part of Kinzey’s books are the “walk around” photos. They differ from all other “walk arounds” by careful selection of the pictures and comprehensive comments that explain many technical details depicted on these images. Usually these comments are as important as the photos.

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Figure 59-1 Bert Kinzey’s book and one of the photos from inside

Continue reading A New Book — and New Fixes in the Model

Final Adjustments of the Model Shape

While working on the cowling details, I discovered that the SBD-5 from the Commemorative Air Force (“white 5”) uses a non-original Hamilton Standard propeller. It has larger hub and a pair of bolts in the middle of the hub barrel edges. (As I wrote in this post, the original Hamilton Standard hubs used in the SBDs were smaller, thus they had a single bolt in the middle of each barrel edge). What’s more, I also noticed that the centerline of my model does not precisely pass through the tip of the propeller dome visible in this photo. When I corrected this mistake, I also noticed that the edges of certain cowling panels in my model are minimally below their counterparts on the photo. I examined this difference and decided that I should fix it by rotating the camera of this projection around the fuselage centerline. It was really a “cosmetic” adjustment — the rotation angle was about 0.7⁰. However, suddenly everything in this model matched better the reference photo — except the horizontal tailplane (Figure 58‑1):

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Figure 58-1 Improved matching of my model to the largest reference photo

Continue reading Final Adjustments of the Model Shape

Details around the Gunner’s Cockpit

The last details that I create in this project stage are the gun doors behind the gunner’s cockpit. In the SBD-1 they covered a single Browning gun. Fortunately, they were wide enough for stowing the double guns, which were mounted in the SBD-2 and SBD-3 by the Navy workshops (Figure 57‑1):

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Figure 57-1 Evolution of the SBD gunner’s cockpit

Note that stowing the ammunition belts of this double gun required additional cutouts in the cockpit rear border. They were covered by slide plates on both sides of the gun doors (Figure 57‑1). In this post I will recreate these details.

Continue reading Details around the Gunner’s Cockpit

Updating the SBD-5 Model

I continue updating the Dauntless versions that I am building in parallel to the basic SBD-3. In the previous post I updated the one important element of the SBD-5 model: its propeller (SBD-3 used an older version of the Hamilton Standard propeller). In this post I will continue this update.

While I already recreated the SBD-5 NACA cowling (see Figure 46-8 in this post), now it is time to adapt the panels behind it. I started by copying the corresponding cowling from the SBD-3. When it appeared in the place, I discovered a 1” gap between this cowling and the SBD-5 inner cowling panel (Figure 56‑1a):

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Figure 56-1 Fitting the rear cowling from the SBD-3 into SBD-5

Continue reading Updating the SBD-5 Model

Modeling Hamilton Standard Hydromatic Propeller

In this post I start finishing the SBD-5 model. It differs in more details from the SBD-3 than the SBD1. One of the most prominent differences is the propeller. I will create it in this post.

In the later Dauntless versions (starting from the SBD-4) Douglas used the new propeller: Hamilton Standard Hydromatic. The SBD-1,-2,-3 used the older constant speed propellers, which used counterweights to oppose the force generated by the oil pressure in the control cylinder. (I created the model of this propeller in this post). The Hydromatic propeller used the oil pressure on both sides of the piston that controlled the pitch. It eliminated the massive counterweights, creating a lighter, smaller, and more precise pitch control unit. Hamilton Standard Hydromatic propellers has been widely used since 40’ (you can still encounter them in the various modern aircraft).

In the Dauntless, these Hydromatic propellers came with slightly modified blades (Figure 55‑1):

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Figure 55-1 The Hamilton Standard Hydromatic propeller (mounted in the SBD-4)

Continue reading Modeling Hamilton Standard Hydromatic Propeller

Updating the Model of the SBD-1

As I described it in one of my previous posts, in parallel to the SBD-3 I build a SBD-1 model and a SBD-5 model. They are in the same Blender file, but in separate scenes. Since I completed the SBD-3 model for this project stage, now it is time to take care of these other versions. These models share all the common objects with the SBD-3, so I have to recreate a few different details. I already modified their NACA cowlings. In this post I will update the SBD-1, because there is just a single remaining difference: the ventilation slot in the side panel of the engine cowling.

The SBD-3 had this slot much wider than the SBD-1 and SBD-2 (Figure 54‑1):

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Figure 54-1 Comparison of the ventilation slots in the SBD-3 and the earlier versions

(I used here an archival photo of the SBD-2, because it had the same side cowling as the SBD-1. There were only 57 SBD-1s ever built, so the photos of this version are not as numerous as the later ones).

Continue reading Updating the Model of the SBD-1

Modeling Hamilton Standard Counterweight Propeller

In the previous post I modeled the blade of Hamilton Standard Constant Speed propeller, which was used in the SBD-1, -2 and -3. The Douglas factory mounted on the hub of this propeller a small spinner (Figure 53‑1a):

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Figure 53-1 The Hamilton Standard Constant Speed propeller (used in the SBD-1, SBD-2 and SBD-3)

It seems that during the service of these aircraft, the ground crew often removed this spinner. It exposed the propeller pitch control mechanism (Figure 53‑1b). There are many photos of the SBD-2 and SBD-3 without spinners, thus I decided that I had also to model this “bare” variant.

Continue reading Modeling Hamilton Standard Counterweight Propeller

Modeling Propeller Blades

The SBD Dauntless used two types of the Hamilton Standard propellers:

  • Hamilton Standard Constant Speed (counterweight propeller) used in the earlier Dauntless versions (SBD-1 … SBD-3). The blades of this propeller had smaller tips (Figure 52‑1a);
  • Hamilton Standard Hydromatic used in the later Dauntless versions (SBD-4 … SBD-6). The blades of this propeller had larger tips (Figure 52‑1b):
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Figure 52-1 The Hamilton Standard propeller blades, used in the SBD Dauntless

These two blades had different shapes. In this post I will recreate the earlier version, which was used in the SBD-1 .. -3 (Figure 52‑1a). Several posts later I will modify its copy to obtain the later model of the blade, as used in the SBD-4 .. -6 (Figure 52‑1b).

Continue reading Modeling Propeller Blades

Cockpit Canopy Details

Before I start forming the frames of the Dauntless canopy (which I created in the previous post), I had to conduct yet another verification of its shape. I placed the canopy rails on the cockpit sides, and verified if they fit the corresponding canopy segments. First I tested the rails of the pilot’s canopy (Figure 51‑1a):

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Figure 51-1 Tracing the rails of the pilot’s canopy

They were formed from open-profile beams (Figure 51‑1b). Why these rails are such an important test tool? Because they always have to be parallel to the fuselage centerline! It sounds obvious, but it can reveal various unexpected errors in the canopy shapes.

Continue reading Cockpit Canopy Details