SBD Dauntless, from scratch

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Wurger, Gnomey - thank you!
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I published my previous post a month ago, but the current stage of this project – detailing – requires less frequent reports. (Otherwise the posts would become rather monotonous: week after week they would describe making similar things, using the same methods). I started this last phase of the Dauntless project by recreating its main landing gear. First, I had to finish it, then I am able to write about this process. Thus I will describe it in this and next two posts. (I will publish them in a short sequence, week after week).

The retractable main landing gear of the SBD was probably a direct descendant of an experimental solution used in the Northrop 3A fighter prototype. In general, it looks quite simple:


The upper part of the landing gear was an "L" – shaped tube, mounted between two wing spars. The lower part, visible below the wing, was a simple shock strut mounted to the wheel axle (see figure "a", below). The axis of the landing gear retraction was parallel to the thrust line and perpendicular to the walls of the spars (see figure above). The shock strut is deflected (by 6⁰) from the vertical axis, so that in the open position the wheel is directly below the axis of landing gear retraction (see figure "a", below):


Figure above also shows various treads of the SBD tires. The tires of the earlier versions (SBD-1, -2 and -3) had no tread pattern (figure "b", above). The simple "straight grooves" treads appeared on the SBD-4 wheels (figure "a", above), while in the SBD-5/6s we can find a more elaborate, "brick" (figure "c", above) or "honeycomb" tread patterns.

Another interesting thing is the lack of the torque arms, that connect the cylinder and piston of the shock strut in most of the other aircraft (figure "a", below):


The SBD manual explains that the designers used splined cylinders and pistons in their shock strut (figure "b", above). It looks like a quite elegant solution for the blocking random torsions of the shock strut piston (less outer parts that are prone to the eventual dust and jams). I did not find any complaints for this landing gear in the veteran memoirs and technical reports (usually they praise the "rugged structure" of the SBDs). However, all other aircraft designs use the torqe arms in their landing gear. Maybe they were just cheaper (i.e. easier to produce)?

Basically the work on the details means that you have recreate "in the mesh" all the parts you can see on the photos. Below you can see how I recreated the upper part of the landing gear leg:


Recreation of such a die-cast part, with all of its additional walls, roundings, is a small challenge. To make it with as simple mesh as possible, I used several modifiers. First, I used the Mirror modifier to automatically generate the symmetric half of this object. (This symmetry was only possible because I decided to split this "L" – shaped part into two objects: this complex die-cast and a simple tube behind it. (This tube is not present in the picture above). Then I recreated all the rounded edges on this object using dynamically-generated fillets. Another modifier (Bevel) creates fillets along all the edges that I assigned a nonzero bevel weight. (The fillet radius is controlled by the value of this weight).

When this upper part of the landing gear leg was finished, I created the cylinder of the shock strut. It was just a tube with an octagonal flange *– nothing difficult. Then I had to create the lower part of the leg:


It was another die-cast, which shaping required some time. (As you can see in the figure above, I formed this mesh from two crossing tubes).

While creating such a detailed assembly, I prefer to model each of its parts as a separate object. It gives me the opportunity to take advantage of its local coordinate system, when I need it. For example – the shocking strut is a tube rotated by 6⁰. When I formed it, I often extruded its faces along this local axis. Another advantage of such a model structure is the possibility of quick, "natural" adjustments of various parts. (For example – piston movement along the cylinder. In my model it occurs along its local Y axis).

Building the landing gear, I tried to check its retracted position as early as possible. Figure below shows first of these trials:


As usual, a small fragment of the retracted landing gear leg protruded from the upper wing surface. I had to re-examine the photos, find which part has the wrong shape, and fix it.

I also used my photo references to recreate other landing gear elements, like the wheel brake disks:


During this work I also found some differences between my model and the reference photo (see the notes in blue frames in the figure above). It seems that my landing gear is somewhat shifted forward.

Such a finding led to many rearrangements in the geometry of this assembly:


In the background of figure "a", above) you can see my original drawing from 2015. After some deliberations, I decided to leave the center of the wheels at its current location, because it was dimensioned on the original general arrangement drawing. However, after measuring tire proportions on various photo, I decided that the SBD used slightly wider tires (30x7.5") than the size (30x7") specified in one of the comments placed on the original drawing from the SBD manual. (Sometimes draughtsman could make such a mistake). To fit the photo, I adjusted location of the shock strut, moving it slightly toward the fuselage. I also shifted downward the axis of retraction (rotation). Figure "b", above, shows how the updated model fits the reference photo. The tires on the photo still seems somewhat smaller than those from my model. However, I decided that this restored CAF aircraft could use a slightly smaller tires (29x7.5"). (This particular SBD-5 also uses at least another non-original part: a different version of its Hamilton Standard propeller).

Another element that requires some adjustments are landing gear covers. Although I created them during the modeling phase, now I have to compare their shape with the reference photo. Preparing for this test, I placed in my model a simple "stick" which I use as the hinge (I set it as the parent of the landing gear cover):


The hard part was to determine the proper axis direction and the angle of this rotation. Surprisingly, the hinge was not lying directly on the aircraft skin (it would be the simplest solution). While it was relatively easy to find for a given hinge orientation a rotation which angle placed the left cover as on the photo, the same rotation applied to the right cover did not match the reference. It required some hours to find a combination that produced an acceptable (although not ideal!) match.

As you can see, I performed a lot of various checking, adjusting and matching while forming the key elements of the landing gear. All of this because it is still quite easy to correct the geometry of this assembly while it is relatively simple. It would be a nightmare, when I did such a thing on the final, detailed assembly, which you can see in figure below:


However, before I finished this landing gear in such a state depicted in the figure above, I had to create several dozen bolts of various size, as well as other details. I also discovered some small secrets of its retraction mechanism. You will find a short description of all of these findings in my next post (to be published next week).

I decided to not enclose the source Blender file to this post, because it would contain just these few basic landing gear components. I will add it to the next post, which describes this assembly in the finished state.
 
Lucky13, Wurger, Gnomey - thank you!
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Today I have written about some details of the Dauntless landing gear:

The SBD shock absorbers had to disperse a lot of the kinetic energy of landing aircraft, minimizing the chance that the airplane accidentally "bounce" back into the air. (This is a key requirement for the carrier-based planes). For such a characteristics you need a relatively long working span between the free (i.e. unloaded) and the completely compressed (i.e. under max. load) strut piston positions. Indeed, you can observe that the Dauntless landing gear legs are much longer in the flight than in their static position on the ground:


The working span of the SBD shock strut piston was about 10" long, while the difference between the static and the free (extended) piston positions was about 7.5".

In the most of the aircraft the landing gear retracts with the shock struts fully extended. When I tried to do such a thing with the Dauntless landing gear, as in the figure above, I discovered that it definitely does not fit its recess in the wing! (see the figure below):


It seems that there was something that compressed SBD landing gear during retraction by about 7". In the case of the Republic P-47 (which landing gear leg shortened during retraction by 9"), such a thing was widely discussed as an exceptional achievement of its designers. However, nobody even mentioned that the same issue was already resolved several years earlier by the Northrop/Douglas SBD team.

The SBD landing gear leg was made shorter during retraction by compressing its shock strut piston. This "compressing" mechanism starts with the cable that pulls the piston upward. The cable is attached to a quadrant, which rotation is controlled by the rail, fixed to the wing spar:


An additional spiral spring, attached to this quadrant (as in figure above), tightens the cable when the landing gear is extended. In this landing gear position the spring "freely" rotates the quadrant, just following the shock strut piston movements:


(You can also see how it works in this short video sequence). Note that this spring ensures that in the fully extended (free) position of the landing gear the tip of the quadrant arm nearly "touches" the rail.

This is the starting position for the piston compression. During the retraction the quadrant rotation axis is elevated upward, while its arm is dragged along the rail (there is a small roller on its tip). In the effect, the quadrant rotates, pulling the cable that compresses the shock strut piston:


You can also see how it works in this short video sequence. (Note that in this video the path of the quadrant arm tip is not perfect. This is the result of a relatively simple real-time rigging. Anyway, it gives the general idea how this mechanism works).

I also recreated the inner details of the landing gear recess:


During the modeling phase I already recreated two spars and two main ribs in the wheel bay. Now I refined their shape, following the available photo reference. I added also the remaining ribs as well as the stringers and the covers (at the rear part of the bay).

As you can see in the picture above, I did not model the lightening holes: as in the case of the wing flaps, I recreated them using textures:


I unwrapped meshes of all these new wing structure elements into the available space on the UV layouts that I used in the outer skin material (B.Skin.Camouflage, refined in my previous posts). The Navy painted the inner space of this wing recess in the same color as the wing bottom surfaces, so there was not any problem in assigning the B.Skin.Camouflage material to these objects. As you can see in the picture above, I also recreated the internal reinforcements of the landing gear cover. The inner side of the aircraft skin is covered with a generic material, named B.Skin.Details.Bottom. (It is assigned to the second material slot of the wing skin mesh, and set in the Material Index Offset field of its Solidify modifier). This simpler material is intended for the smaller details, and uses exclusively the generic, procedural "noise" textures for the dirt/ref effects. Thus it does not require any time-consuming UV unwrapping. In the figure above I used it also in the cover fittings. I only have to remember to alter the basic color of this simpler material when I switch to another camouflage scheme. (In the future, I will also create a similar material for the details on the upper surfaces – it will only differ in the basic color).

Because this B.Skin.Details.Bottom material has no regular bump map, I had to recreate more landing gear details "in the mesh". In particular, I had to add the bolts (and nuts) visible on the reference photos. I created each of them as a separate object:


All these bolts are clones of a few basic original bolt meshes (one with the octagonal head, others with the flat one). Among these originals there are also two or three variations of the bolt length. By default these bolt meshes are covered with a generic "steel" material. When I needed to "paint" them into different color, I alter their material assignment. (In such a case, I had to switch them into the object – based material mode).

Sometimes some of these bolt objects are also useful as the reference objects in the rigging, but I will discuss it in the next post.

I also like to have a look at the retracted landing gear inside the wing structure. When you can see these two assemblies together, suddenly the reason for some strange features of the particular rib or spar shape becomes clear:


In figure above you can also see a couple of bolts forming an octagonal group on the rear spar. In general, I recreated most of the bolts and rivets on this spar using the bump texture. However, this was a special case: in the original airplane these bolts had quite large heads. What's more, they were placed on a "stack" of two subsequent panels. I simply run out of the available grayscale of the bump texture in this particular place, thus I decided to recreate these "topmost" details in the mesh. (Just an exception from my general modeling tactics of using the textures as often as possible).

Figure below shows the complete landing gear in the open position, the shock strut fully extended:


The decision to use a simpler materials that do not require UV-mapping has certain disadvantages. The most important of them is that I am not able to paint the small stains around the landing gear bolts and other kinds of the local dirt. But this is just the consequence of the level of details that I assumed for this model.


Among the materials that I have to deliver in winter 2018 I will not enclose any close-up pictures of the landing gear or other details, thus I can use the simpler materials here. However, in such a harsh light as in Figure 80‑10 the elements covered by the B.Skin.Details.Bottom material seem too "clean". I will definitely work on this issue, increasing the contrast of its "noise" textures to give these landing leg and brake disk a more "dirty" look.

In the next post I will describe how I rigged this landing gear. (I will describe building a kind of "virtual mechanism" that allows me to extend/retract the undercarriage using a single slider. I already used it, making the video sequences presented in this post).

In this source *.blend file you can evaluate yourself the current (i.e. non-rigged) version of this model.
 
Wurger, Gnomey - thank you!
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In previous post I discussed how the SBD landing gear retracts into its wing recess:


In principle, it is simple: the landing gear leg rotates by 90⁰. However, the parts responsible for shock strut shortening during this movement increase mechanical complexity of this assembly. The figure above does not even show the deformations of the brake cable, which follows the shock strut piston movements.

For some scenes I will need the landing gear extended, while for the others – retracted. In practice, moving/rotating each part individually to "pose" my model would be a quite time-consuming task. That's why I created a kind of "virtual mechanism", which allows me to retract/extend the landing gear with a single mouse movement. In the previous post I already presented its results in this short video sequence. In this post I will shortly describe how I did it.

In general, I coupled some key elements (objects) of the landing gear using so-called constraints. For example, I connected the rotation of the landing gear leg with the movement of a special "handle" object. To do it, I used a Transform constraint, attached to the parent object (the axle of the retraction) of the landing gear leg:


I created an auxiliary (non-rendered) "handle" object (X.600.Wheel.Handle). The Transform constraint of the landing gear leg axle (0.604.Strut.Axis.L object) converts the handle linear movement into landing gear rotation. Thus when I shift the handle object upward, landing gear leg rotates, retracting into its place in the wing. To restrict the range of this rotation, I assigned to the handle object additional Limit Location constraint. It restrict its possible movement to a 40-unit long span along local Z axis.

The more detailed explanation of my methods for the "mechanization" of the landing gear would take too much space in this post. However, some years ago I published an article on this subject (in "Blender Art Magazine"):
http://airplanes3d.net/downloads/forums/mm/lgear.pdf

To read this article, click the picture above or this link. I hope that this publication will explain you the general idea and typical implementation of such a "virtual mechanisms".

The format of my posts (10-11 pictures) allows just for a quick review of the SBD landing gear constraints (one picture per a subassembly). Thus the next element coupled with the handle object (using another Transform constraint) is the landing leg cover:


In the previous post I added many bolt objects to the landing gear, and mentioned that some of them will have an additional use. So this is just such a case: I set the forward bolt of the cover hinge as the parent of the whole cover assembly. (Because it lies on its rotation axis). A Transform constraint, assigned to this bolt, forces it to rotate in response to the handle vertical movements. Note that the range of rotation of this cover (101⁰) is greater than the range of the landing gear leg rotation (90⁰).

Another Transform constraint converts the rotation of the quadrant object into movements of the shock strut piston:


This relationship seems quite straightforward: when the quadrant rotates upward, the piston shifts up, when it rotates downward, the piston shifts down – as if they really were connected by the cable. Rotation of the quadrant is forced by its Locked Track constraint, which arm "tracks" the auxiliary (non-rendered) target object (the red, small circle in the figure above). Effectively, location of this quadrant target controls the shock strut position.

The full motion path of the quadrant target object contains an arc and a straight segment:


The arc corresponds to possible piston positions for the extended landing gear (see this short video sequence). The linear segment corresponds to the forced compression of the shock strut during retraction, when the quadrant arm tip slides along the internal rail. (You can see this motion here, although in this video the path of the quadrant arm tip is not ideal).

I did not want to use the animation motion path here, because it creates a "deterministic" movement ("frame by frame"). Instead, I wanted a general solution, controlled by a handle object instead of the animation frames. Thus this is the most complex subassembly in this landing gear rig. I will describe it in two pictures: one for the extended landing gear (implementation of the movement along the arc), the other for the landing gear retraction (movement along the linear segment).

When the landing gear is extended, the rotation of the quadrant target is forced by its "grandparent" object. This is an Empty instance, named after the source of the original movement it mimics: X.Quadrant.Spring.Control:


A Transform constraint converts the vertical movement of the additional handle object (X.600.Strut.Handle) into rotation between -24.7⁰ and +118⁰. There is another Empty object (0.607.Target.Left.Parent), attached (by the parent relation) to the X.Quadrant.Spring.Control. Simultaneously, 0.607.Target.Left.Parent is the parent of the quadrant target object. (The reason for such an indirect relationship will become clear in the next figure). When the landing gear is extended, this chain of "parent" relations forces the quadrant target object to move along the arc path when the handle object moves up and down. To not exceed the minimum and maximum angles of this movement (and in the effect – the lowest and highest shock strut piston position), the location of the handle object is restricted by a Limit Location constraint.

Note that this smaller handle is the child of the main handle, used for the landing gear retraction (X.600.Wheel.Handle). Note also that the Transform constraint that forces this rotation, evaluates the handle position in the World Space (figure above, bottom right). This means that regardless of the position of the smaller handle, the shock strut will be fully extended after moving the main handle along the first few units along its way up. (So that I do not have to care about the initial piston position when I am starting landing gear retraction: it will set up itself).

During landing gear retraction the locations of the quadrant target, its parent, and "grandparent" become dispersed. Figure below shows how it looks like in the middle of the main handle (X.600.Wheel.Handle) movement:


The parent (0.607.Target.Left.Parent) of the quadrant target object just "delivers" it to the rail line and stops there. (This is the end point of the rotation of its parent: X.Quadrant.Spring.Control object, as you can see in the previous figure). Then the quadrant target object is "dragged" by the landing gear retraction along the rail. I tried to obtain this effect by assigning it two constraints:
  1. Limit distance, which forces a fixed distance between the target object and the quadrant axis;
  2. Limit location, which restrict the possible location of the target object just to a certain span along its parent X axis (which I set parallel along the rail);
In theory, for such a constraint combination there is always just a single possible location of the target object (marked in the figure above). Unfortunately, it seems that Blender treats these constraint with certain "flexibility". In the effect, the quadrant arm tip "sinks" into the rail. This effect is especially visible at the beginning of the landing gear retraction. Well, I tried hard but I could not find a better solution for this movement. Finally I concluded that I can left it in this state: this is a small part, which movements are partially obscured by the wing recess. When I need to make a close up, I can prepare a "deterministic" animation motion path for the quadrant target object.

The last rigged subassembly of this landing gear was the elastic brake cable. Because I used in this implementation another (better) solution than described in my article and book, I will discuss it shortly below


First, as in my previous model, I formed the curve (figure "a", above), that deforms the simple tubular mesh into the brake cable. (I used a Curve Deform modifier here). Then I created a simple armature consisting two bones: upper and lower (figure "b", above). The armature object is attached (by a parent relation) to the strut cylinder. Thus the origin of the upper bone is also fixed in this way. I assigned to the lower bone an Inverse Kinematics constraint, and set its Target to an auxiliary Empty object at its end. This target object is indirectly (via the brake disk) attached to the piston. In the effect, this armature follows every piston movement in a natural way – like a pair of the torque scissors. Finally I attached subsequent curve vertices (control points) to the nearest armature bone (figure "c", above). I also attached (via parent relation) the ankle object (at the bottom end of the brake) to the bottom bone. (So that it will follow its rotation). In the effect, the brake cable deforms when the shock strut piston is shifting, following its movement in a natural way. See this short video how it works.

In my previous model (the P-40B) I used for the same purpose a different, less effective combination of the constraints. I think that in the future I will always use the solution as in figure above, not only for the brake cables, but also for the torque scissors (the SBD landing gear did not have such an element).

Finally, I applied my Handle Panel add-on to create a convenient landing gear controls among the Blender panels:


See this short video how it works. Now I can extend/retract the landing gear with a single mouse movement. I even do not have to know, where their handle objects are – the add-on will discover them automatically. (I just have to arrange them in the model space in a certain way – see the add-on description for details. This is a general utility, you can use it in your own Blender models).

The next part to recreate is the tail wheel assembly. I will report this step within two or three weeks.

In this source *.blend file you can evaluate yourself the current version of this model.
 
Wurger, Gnomey - thank you!
BTW: do you know, why all the linked images in my previous posts become copied and minimized!? The posts are less readable now....
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The Dauntless had fixed tail wheel of a typical design among the carrier-based aircraft. The tail wheel assembly consisted a fork connected to two solid-made beams, which movement was countered by a shock strut. The beams and the shock strut were attached to the last bulkhead of the fuselage:



The bottom part of this assembly was covered by a guard and a fairing. Both of these elements were attached to the lower beam. The archival photos reveal that the bulky fairing was often removed:



There were two tail wheel versions: the smaller, solid-rubber wheel for the carrier-based aircraft (as in figures above), and the larger, pneumatic wheel for the ground-based aircraft. As you can see on the example of a SBD-1 (below), they could be replaced in a workshop:



Figure above shows two SBD-1s, which were exclusively used by USMC squadrons in the continental United States. All of these 57 aircraft were built in 1940. As you can see in the photo above, they were originally delivered with small, solid tires. However, in the photo below, taken a year later, one of these SBD-1s has the large, pneumatic tail wheel. It seems that Douglas delivered these large wheels to the Navy / USMC as an optional kit, which could be mounted when needed.

The smooth tip of the tail was mounted to the last bulkhead as a light, easily detachable tail cone. It covered the tail wheel shock strut, as well as the rudder and elevator control mechanism. There was a large opening in the bottom of the tail cone. For certain sunlight directions (for example, in a dive) you could "look inside" the fuselage:



As you can see in the figure on the left, the tail wheel fairing effectively closed most of this view (figure "a", above), so that you could see just the catapult holdback fitting, two ribs and their stringers. However, when you remove this fairing, you can see many details inside (figure "b", above). Of course, they are not visible on most of the photos. These details are hidden in the pictures taken on the ground. In most of the in-flight photos this opening seems to be too small to reveal the interior details. However, thinking about the future scenes of diving bombers, I decided to recreate at least the key internal elements of this tail cone.

While the tail wheel in the SBD does not retract, it follows the shock strut compression. Thus recreation of this assembly requires some initial adjustments of these moving parts. (For example: I had to make sure that the wheel leg will fit into the tail cone). I am shortly describing this process below:



I started with the tire, its fork and the guard, which are present on my reference photo (figure "a", above). I also added the stringers along the border of the opening in the tail cone. Then I placed the simplified shapes of the tail wheel beams. At the beginning I did not know their proper width, thus their initial mesh was a simple, four-vertex trapeze, ready for eventual adjustments. In figure "b", above, you can see also a bolt at the end of each beam. They were important parts of this "virtual mechanism". No armature was needed in this case. I decided that the lower beam will be animated by the handle movement. Thus I forced the upper beam to follow its rotation using a Copy Rotation constraint. Each of these two bolts is attached (by parent relation) to the corresponding beam. The tail wheel fork is attached (by parent relation) to the lower bolt. Simultaneously this bolt rotates, tracking the center of the upper bolt (using a Locked Track constraint). Thus, when I rotate the lower beam, it rotates the whole assembly (as in figure "c", above). Then I adjusted the width of the guard and the beams so that in the fully deflected position it fits the opening in the tail cone (figure "d", above).

Once the overall size of the beams was determined, I recreated their shapes, as well as the catapult hold back fitting, shock strut, and the tail wheel fairing:



The catapult fitting was attached to the ribs of the tail cone. Its side arms were fitted between the tail wheel fairing and the stringers running around the border in the tail cone opening. As you can see in figure "a", above, I started with the conceptual lines of this part. Then I used them to form the final "Y" – shaped fitting (figure "b", above). Using similar methods I recreated the beam details. (I could do safely, because they were already fitted to the tail cone, and I do not expect any further changes in their shape). Finally I also added the internal ribs of the cone (figure "c", above).

In the next step I recreated the rudder/elevator torque tubes and their fittings:



Figure "a", above, shows the rudder torque tube. It was mounted on a tripod. Note, that the rudder rotation axis lies in the front of this tube. (It rotated around the bolt that joined the torque tube with the tripod). For this level of detail I did not recreate the control cables. (Perhaps I will do it in the future). I also formed the elevator torque tube (figure "b", above). Its rotation axis also lies in the front of the tube. According the maintenance manual, there were also two pulleys for the elevator trim tab cables (figure "c", above). Unfortunately, I do not have any precise photo of this detail. I recreated their brackets using two rough sketches from the maintenance manual, but about 50% of their size and shape is just my guess. If any of you have a photo of the details from figure "c") (for example – from a restored SBD), let me know. I would appreciate any of such pictures.

Figure below shows all of the tail cone internal details that I have recreated so far:



For the assumed level of details I simplified some small elements, like the trim tab pulleys. I also did not recreated other minor, less visible elements like control cables, electric cables, some additional fittings and bolts. I will recreate them later, when I decide to make cutaway pictures of this model.

To recreate the alternate, "solid" version of the tail wheel, I switched to another reference photo:



The SBD on this reference photo was restored for Pacific Aviation Museum Pearl Harbor. Although the restoration teams do their best to recreate their "birds", sometimes you can find a non-original part on their aircraft. In this case it was the tail wheel fairing: it is smaller and simpler (figure "a", above) than the original part (figure "b", above). However, the rest of the tail wheel assembly seems to be original, thus I used this photo as the reference for the "carrier-deck" version of the tail wheel and its fork.

Finally I also added the tail hook (it was removed only from the A-24s, delivered to the Army). As you can see, it was accompanied by some minor details:



Figure below shows the final result: the complete tail wheel and hook assemblies:



As you can see, I initially painted the internal surfaces using the standard Interior Green color, but then I was starting to have doubts. In the restored aircraft these surfaces are usually painted in the gray camouflage color (the same as used for the aircraft underside). Unfortunately, I did not have any historical photo of this area to determine how it was painted in the original SBDs. Most probably I will update the color of this detail according the restored aircraft.

The next part I am going to recreate is the R-1820 engine (a simplified version, for the external pictures). However, for reasons beyond my control I have to take a break from this project. I will write next post in the spring (2018). So, for time being my SBD will look like this:



In this source *.blend file you can evaluate the model.
 


To answer your question: the effect is because of the recent upgrading of the forum soft and changing made by the site owner.
 
To answer your question: the effect is because of the recent upgrading of the forum soft and changing made by the site owner.
I reported this issue in the "issues" thread and the Administrator quickly restored the original links. Now the pictures are in their original (intended) size. Excellent technical support! (I was really afraid that I would have to update each post manually)
 
Yes I saw your report there. I was going to send the info to our main admin. But yuor post was enough. However the smaller pics aren't a problem becuase the difference is the way a pic is inserted into a post. Because the new forum soft use its own picture browser the small size images are the default ones. If you clcick a such "thumbnail" you open the browser ann can watch a pic of the larger size. In tha way loading pages is faster.
 
I am impressed with the work that you´re doing Witold, your diagrams, images, descriptions and the photographs are of a very high level of work !!
It is impressive, many, many congratulations for what you have achieved so far, ... and what we still need to enjoy!

Question: I can have your consent to share your Thread to a cousin who is also involved with the type of software you use.

Saludos y felicidades
 
How did you manage to perfectly line up the images? Normally I find most drawings have tiny misalignments due to the way they were scanned in. Drives me nuts and I'm not the only one (I don't know her real name, she has so many, but she uses the handle KJ Lesnick on the Secret Projects forum).
Note: for editing these images I use two free, Open Source programs: GIMP (it is similar to Adobe Photoshop) and Inkscape (it is similar to Corel Draw or Adobe Illustrator). You can find more about them in this e-book.
I have both of those! Inkscape's better for text (because the other is so awful), but the other's better for scaling.
 

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