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Witold Jaworski

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Everything posted by Witold Jaworski

  1. In principle, you are definitely right: it gives you more control over the UV mapping. I suppose that you do not need the Subdivision Surface modifier in most of the tank elements(?). I decided to unwrap my model in the other way, because I apply the Boolean modifiers to the elements smoothed by the Subsurf modifiers. It would be much more difficult to manage the resulting, subdivided meshes, because they would have at least 16 times more faces. I decided that in my case the better trade of is the unwrapping of the control mesh. In some certain places the result goes wrong, but I can fix it wi
  2. 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
  3. Well, I will keep these modifiers to the end! First, it is much easier to unwrap in the UV space the initial meshes (because the number of their faces is by a magnitude lower than after applying these modifiers). Second, I never know when I find another reference material which will show me that I have to correct this aircraft shape. I want to keep the elements of this model in the simplest state, ready for eventual modifications. I suppose that I will do UV-mapping in mid-July, then I will report how I do it.
  4. 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
  5. In my post from the previous week 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 (as in figure "a", below): It seems that during the service of these aircraft, the ground crew often removed this spinner. It exposed the propeller pitch control mechanism (figure "b", above). 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. These constant speed propellers were in wide use during the
  6. Thank you! In fact, it is not as difficult as it seems! The research in the reference materials is harder. My goal is to popularize this new branch of our hobby, thus I also prepared a detailed "step by step" guide: This e-book explains from the very basics, how to build such a P-40B as the one on its cover. I think that at least the "3D" modeling skill can be useful in the future. (Imagine making the missing/modified model parts on a 3D printer...)
  7. 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 (see figure "a", below); Hamilton Standard Hydromatic used in the later Dauntless versions (SBD-4 … SBD-6). The blades of this propeller had larger tips (see figure "b", below): These two blades had different shapes. In this post I will recreate the earlier version, which was used in the SBD-1 .. -3 (figure "a", above). Several posts later I will modi
  8. Today I will add the basic details of the cockpit canopy: its outer frames. However, before I started this work, I had to conduct yet another verification of the canopy 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 (see figure "a", below): They were formed from open-profile beams (see figure "b", above). 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 unexpect
  9. Thank you very much, I just thought about the detailing phase: it would be an overkill to describe how to form every bolt of the cockpit interior, or the landing gear :). OK, we will see how it goes!
  10. 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 (see figure below). (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
  11. In this post I will form the fuselage panels in the front of the windscreen. In the SBD there were two hinged cowlings, split in the middle. They allowed for quick and easy access to the M2 gun breeches and the internal cabling behind the instrument panels: The parts of the fuselage around the cockpit are always tricky to model. It especially applies to the panel around the windscreen. When you obtain the intersection edge of these two objects, it can reveal every error in the windscreen or the fuselage shape. To be better prepared for this task, I created an auxiliary, simplified mode
  12. Richard, thank you for the photos! Now I know how this air intake looks like :) In this post I will create the next section of the engine cowling. I copied its forward edge from the rear edge of the inner cowling panel. Then I extruded it toward the firewall: I am going to split this object into individual panels, thus I already marked their future edges as “sharp” (as you can see in the figure above). It allowed me to preserve continuity of the tangent directions around these future panel borders from the very beginning. In the next step I created the space necessary for the covers
  13. Thank you, Richard! Indeed, I have found your thread several weeks ago (on the Britmodeller forum) and bookmarked it as an useful information resource :)/>. Beautiful model! Yes, even using a large photo collections I often have troubles in determining the precise shape of a particular detail - I think that we can ask each other about such a difficult items, exchanging the photos and other information. For example: I am struggling to determine the precise shape of the main carburetor air intake (and the cowling around it), which in the SBD-5 was located under the NACA cowling, behind t
  14. This relatively short post contains a digression about the aircraft shape. It was sparked by a suggestion that I received. Some time ago Alan from SOARING Simulator.com pointed me that the SBD NACA cowling was not as smooth as in my model (thanks, Alan!). He suggested that its contour was created from a combination of two or three arcs and a straight segment: I thought about it and decided that this is a highly probable hypothesis. For most of the 20th century aircraft engineers did not have CAD systems. During that “BC” (“Before Computers” :)) era the typical problem in the ship, airc
  15. In this post I will finish the engine cowling of the Dauntless (of course, for this stage of the project). In the previous posts I formed its outer panels. In the case of the air-cooled radial engines like the one used in the SBD, there is always another, inner panel: the central part of the cowling. It is located behind the cylinders and exhaust stacks. In the classic arrangement of the NACA cowling it is nearly invisible. In the SBD-1..-4 you could see only its outer rim. That’s why I had to use all available pictures of the Dauntless engine maintenance or the wrecks, to learn about its gene
  16. #1 Greywolf: thank you for following this thread! I hope that I will somewhat speed up this work at the end of April. This week I have worked on the carburetor air scoop. This scoop passed significant evolution in the subsequent Dauntless versions. In the SBD-1 there was a rather large air duct placed on the top of the NACA cowling (see figure "a", below): However, it was quickly discovered that it obscures one of the most important spots in the pilot’s field of view: straight ahead and slightly below the flight path. That’s why it was somewhat corrected in the next version (SBD-2). I
  17. The gun troughs in the aircraft usually are tricky elements. Their edges depends on the shape of two curved surfaces: the fuselage around the recess and the tubular inner surface. When you make mistake in any of these two shapes — you have to remodel the whole thing. In the SBD there are two symmetric gun troughs in the upper part of the NACA cowling. Figure below shows the left one: As you can see on the photo, these recesses were formed in a separate metal sheet. It was riveted afterwards to the main body of the NACA cowling. I will repeat such an arrangement in my model, because us
  18. In this post I will shape panels of the Dauntless NACA cowling. Working on the scale plans a couple months ago I came to the conclusion that the basic shape of this cowling was the same in all the SBD versions (see Figure 4.6 in this post). You can find the differences in their ‘ornaments’, like the sizes and locations of the carburetor air intake, or the number of their cowling flaps. Thus I used the high-resolution, long-lens photo of the SBD-5 (described in the previous week), to determine the ultimate shape of this cowling, and the split lines of its panels (figure "a", below): Ba
  19. C2j - thank you very much for following this thread! It seems that even a photo camera and an appropriate software is enough: the author of this thread walked around a DC-3 taking serial photos, then used Agisoft photoscan to recreate it as a 3D object. As you can see in this picture, the "raw" result requires further work, but it creates a solid reference. I suppose that there are more advanced systems, which produce results of better quality
  20. In this post I describe a break in the modeling that I made this week, because I had to fix my reference photos before the further work. The reason for this fixing was simple: the NACA cowling of my model did fit only the long-lens photos. For the further work I needed more information. This information was available in the high-resolution photos made by the Pacific Aviation Museum Pearl Harbor. However, they are slightly distorted. In the ‘mathematically ideal perspective’ calculated for the computer cameras all of the straight lines remains straight. Unfortunately, the real-world camera len
  21. In this post I will continue my work on the engine cowling. I started it in the previous week by forming a “first approximation” of the forward part of the SBD Dauntless fuselage. Now I will create the last elements of this auxiliary object. First of them are the covers around the M2 gun barrels. They were hinged around their inner edges, and their cross-section varies from a semi-circle at the NACA cowling to a flat line at the firewall: I started forming this cover from a conic cylinder, created around the gun barrel: Then I cut out its bottom part and flattened its end sect
  22. SBD Dauntless had a radial engine hidden under typical NACA cowling. The Douglas designers placed its carburetor air intake on the top of this cowling, and the two Browning M2 guns behind it. In the result, the upper part of the SBD fuselage, up to the pilot’s windscreen, had a quite complex shape: I am sure that I will tweak this shape multiple times before I reach the most probable compromise between all the reference photos I have. It will be much easier to do it by modifying a simple mesh instead of the complex topologies of the final cowling. Thus I decided to create first a simp
  23. In the previous post I formed the shape of the SBD Dauntless tail tip. In this post I will finish its “closing strip” that contains the running light frame. I will also verify the overall shape of the tail tip using the available photos. There is one thing I didn’t mention in the previous post, just to keep the narration focused on the pure modeling. Before the modeling I carefully studied the reference photos. In the result I found differences in the shape of the curved trailing edges of the fairing behind the elevator. On the photos you can see a straight fragment of this edge (figure "a"
  24. The tip of the SBD tail was a light fairing, attached to the last bulkhead (at station 271 — see figure "b" below). That’s why you can see “NO PUSH” label on the photo in figure "a". The tail wheel was attached to the bulkhead 271, which transferred the resulting loads forward, via the tail structure. The tail tip fairing was always free of any significant loads. However, the shape of this part is a combination of the empennage fairing and the last fuselage segment. What’s worse, there is a large opening at the bottom — for the eventual tail wheel deflection: I had no initial idea abou
  25. After the previous post I decided to simplify the empennage fairing. Originally I created it from two separate objects: the fin fairing and the tailplane fairing, split across their fillet. Now I decided to eliminate this troublesome seam by joining these two meshes into single object: I will split it later, along the bottom rib of the fin (there was another panel seam in the real airplane). To simplify creation of the original overlapped panels, I simultaneously split the fin into the forward and the rear part, along one of the original seams. As you can see in figure above, there ar
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