Ivan's Workshop - AF99 Tutorial - C205 Veltro

Radiator Bleed

As expected from a Radiator that spans two groups (Body,Main and Tail), there were some bleeds from underneath where the Radiator overlapped the Aft Fuselage. Removing this bleed was fairly easy: Just cut the Radiator apart so that one piece can be in the Tail and one in Body,Main.

I was hesitant to expend an extra component here because on typical projects, Components are used up rather quickly. In this project, the issue appears to be a Parts limitation rather than Components.

- Ivan.
 
Cutting Glass

Perhaps it is really plexiglas or plastic.

Creating the Glass Parts of the Canopy is really very easy. The Canopy Frame can be used as a reference to locate all the pieces of the Canopy. This was one of the factors that determined where to put the Frame Parts.

There is only one exception to the idea of connecting all the vertices in an opening to create that Glass pane.

The First Screenshot shows the Pane in discussion. Note that the lower edge of this opening has the edge include a slight concave bend. We must use that point to split the two Glass Parts that go into that opening. Otherwise, the glass will overlay the frame in certain views.

The Second Screenshot shows the results of roughly 5 minutes worth of creating Glass Panes.

The Canopy Frame and Canopy Glass illustrate a very important idea: Piece A can't bleed through Piece B if Piece A ISN'T BEHIND Piece B. Note that for the two Components (CanopyGlass and CanopyFrame), neither one is in the foreground OR in the background. There is no occasion in which either Component can bleed through the other one.

- Ivan.
 
Main Gear Part 1

Other than the Wheel and Strut, all of the pieces that make up the Main Landing Gear on each side are fairly simple polygons. A check of the drawings for this aeroplane shows that the front of the Main Gear Outter Doors and the little Center Doors line up almost exactly. This means that the retraction arc of the Main Gear is entirely horizontal and aligned with the longitudinal axis of the plane. Another observation from the drawings is that the Wheels fit into the leading edge of the wing fillet with little or no room to spare.

First Screenshot:
The outter Gear Doors are also fairly well determined by the locations of the parts they need to cover: The Strut and the Wheel. The edge of the Gear Door is very close to the edge of the wheel.

Second Screenshot:
A reference line is generated here for the location of the Strut. I got it close, but not all that exact when building to this line. Note also that the single piece Gear Door has been subdivided into two Parts to make each part convex in outline.

Third Screenshot:
The sections of the Strut at its endpoints are determined here. I chose Hexagons which I imported from the Storehouse. They are rotated as appropriate and then resized and tilted to match the wing on the top end and be square with the Strut on the bottom end. Although it is not shown here, the first hexagons were 0.15 Foot Radius which I thought was a bit too small. The second set is shown here and is 0.20 Foot Radius.

Fourth Screenshot:
This shows a Glue Part being created to attach a piece of the Fork to the Strut. Note also that the Fork is not shaped as it was built here. The section of the Fork between the Wheel and the Outter Doors. We really can't represent everything in a visual model with this few polygons.

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Main Gear Part 2

Building the Parts took a LOT of time.

The First Screenshot shows the Assembly Sequence. While doing the assembly, I noted that there was a possible bleed of the Top Scissors Link through the Brace. This isn't a great concern because the only place where this can be seen is from the top THROUGH the Wing surface.....

The Next Screenshots show how the Main Gear looks from the Simulator. The colours can be compared with the Assembly Sequence.

Good Night.
- Ivan.
 
Main Gear Part 3

The Inner Gear Doors can be created in a fairly simple fashion.

The First Screenshot shows the creation of a reference Part created off the Main Gear Door and Wheel that is used to create the Inner Gear Doors. The basic idea is that the inner gear door must fit around (be larger) than the Wheel it covers and also meet the Door attached to the Strut.

The Second Screenshot shows the reference Part rotated -86 degrees (via experimentation) to match the underside of the wing and fuselage.

The Third Screenshot shows a door that is created to be 0.20 Feet from the aircraft centerline. 0.20 Feet is a simple guess. The doors are close together but I don't know exactly how far. It COULD be 0.10 Feet so I may adjust this at a later date.

The Part shown in the Third Screenshot is then rotated -90 degrees and the points adjusted to be aligned at 0.20 off the centerline. This isn't quite the final part. Note that the bottom of this part is concave. It needs to be divided into two Parts so that texturing it does not change its shape.

These parts are placed in the Gear,Center Group. It will bleed slightly through the Radiator when viewed from the back, but to do otherwise at this point will cost too much for resources. The bleed is not severe.

The Reference Part is also used to check the location of the wheel as compared to the Wing Fillet outline to make sure the Wheel CAN fit in the Fillet area. Note also that Two Fuselage underside parts are in the Third Screenshot to show where the Wheels and Doors are located when retracted. Several of the Fuselage underside Parts werre separated out into another Component so that they can be textured Top-Bottom rather than Left-Right as the rest of the Fuselage is done. This can be seen as a Tan coloured Component in one of the screenshots in Main Gear Part 2.

- Ivan.
 
Canopy Frame Simplification

The total remaining resources in this Project are relatively low, so I went back to the Canopy Frame to see what duplicated Parts could be removed without affecting the visual.

The Screenshots here show the differences. The only other alteration that needed to be made was to change the angle of the Glue Part for the Windshield Frame to tilt further back. 18 Parts were removed.

- Ivan.
 
Wing Simplification

The Wing Fillets have been conspicuously absent for some time. This is because in looking at photographs, I believe that my initial concept of how they would fit together was seriously flawed. The actual Fillet on top of the Wing is nearly non existent at the Front and relatively small at the rear. The Template I built from drawings needs to be reworked.

Another observation was that the Trailing Edge of the Wing is so close to a straight line on the last two sections that they can effectively be combined into one with no degradation in the visual model. This simplification of the wing only reduces the Parts count by 4 (2 on each side) but the vertices will line up better with the Fillet.

The Screenshot here shows the last two sections of the wing and how close they are to being straight.

- Ivan.
 
Wing Simplification Result

Here is a fairly serious bleed on the Trailing Edge of the Left Wing. I do not believe this resulted from the removal of a polygon, but it does need to be corrected by triangulating the last section of the upper wing surface.

Note the Tan Wing Fillet. This is obviously much smaller than the space that was left for it on the Fuselage. Creating it was a simple matter of connecting the dots between the Wing Root and the Template for the Wing Fillet. When the shape of the Wing Fillet is final, it is a very simple matter of adjusting the Fuselage parts to close the opening. Just about all the Fuselage and Nose Parts are vertical where they connect to the Wing Fillet, so there is no change of shape by moving points up or down.

The Trailing Edge of the Fillet here is almost as high as the trailing edge of the Wing rather than a continuation at the angle of the rest of the Wing. This is what the drawing showed, but it does not appear to be that way in photographs. When in doubt, Photographic evidence overrides drawings.

- Ivan.
 
Fuselage to Radiator Contour

This area on the model doesn't really fit together all that well. The Trailing edge of the Wing Fillet is too high but it really can only be lowered a small amount before making the underside of the Fuselage concave. The attached screenshot is a view of the area between Wing Fillet, Radiator and Fuselage and shows the results of lowering the end of the Wing Fillet and how it affected the Contour at BulkR0565.

Note that there are about 8 Parts that all come together at this point and all need to be adjusted. I had to do this twice. The first try was close but I thought the shape would be improved by adjusting up by 0.01 Foot.

Note that once this point was adjusted down, the points at the joint between Fuselage and Radiator didn't line up any more and also needed adjusting. Here we can see the angle of the projected midpoint and how it matches to the angles fore and aft. Once this part was adjusted, Three Fuselage Parts were affected and a bunch of Radiator parts as well.

Each of these adjustments is incredibly tedious, but improve the shape of the final result. When working a project, the designer needs to figure out when the result is satisfactory.

- Ivan.
 
Revised Supercharger Intake

The Supercharger Intake was an overly detailed part and I knew that from the beginning. Each row was 8 polygons and there was a total of 8 rows. The revised version has 6 polygons per row and only 5 rows total. Yes, it is a bit more crude. This is undoing the choice of a 12 sided circle over the 8 sided circle as a cross section.

This is what happens when you run out of resources in AF99. I wish to add some more pieces in this project and can't do it without simplifying the Supercharger Intake. The total number of Parts saved was 33 but the final version will likely have a couple more than is shown here.

- Ivan.
 
Flaps Part 1

Creating Flaps is mostly a matter of making a Part that matches the surface of the underside of the Wing and also has the correct outline. In the case of the Veltro, the factory dimensions state that the chord of the flap is 385 mm inboard. The inboard chord of the aileron is stated to be 360 mm which can also be taken as the outboard dimension of the flaps. The inboard edge of the flaps start at the wing fillet area and the outboard edge is at 10.00 feet from the centerline.

With these dimensions, getting the outline is easy. The resulting part is then matched to the surface of the polygon at the trailing edge of the underside of the wing: WingLB06. Matching the inboard edge is easy. A new outboard edge is created by using the Point Editor to insert points until one turns up at 10.00 feet.

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Flaps Part 2

Each Flap Part is then Rotated about the three axes until it lines up on the leading edge with the original Part which will serve as the Flap Well.

First we will start with the Outboard Left Flap.
The Pitch rotation is easy: 45 Degrees because that is the angle of travel.
The Yaw rotation is -5.3 degrees gotten by experimentation.
The Bank rotation is -3 degrees.
The forward edge of the Flap will be close, but probably won't line up perfectly with the Flap Well. Snap the vertices to the Flap Well so that there is no gap.

The Inboard Left Flap is done pretty much the same way.
The Pitch rotation we use in this case is 46 degrees so that it will show up just a little differently to emphasize that there is a gap between two Pieces.
The Yaw rotation is -5 degrees.
The Bank rotation is -3 degrees.

The Right side Flap Pieces are just mirrors of the Left. Note that on this aeroplane the mirrored parts will not be an exact match but the differences aren't really visible because of the way the Wings were created. The taper is very slightly different but the dihedral and chord is VERY close.

Adjustments to the Flap Pieces should take them slightly away from the major pieces of the aircraft. Adjustments to the Flap Wells should put them CLOSER to the pieces of the aircraft. If a Part is intended to represent an opening, it would look rather strange if there were an air gap between the opening and the body part (such as a Wing in this case). If the Opening were slightly within the Wing, it would look just fine.

Aftter the creation of the actual Flap Pieces, the attachment to the rest of the aircraft still remains. The Glue Parts are trivial to make. The assembly groups and sequence still need to be worked out.

- Ivan.
 
Supercharger Intake Part 5

The Supercharger Intake as we left it earlier had a 12 sided circle as an opening but the cross sections were 8 sided circles. Because of the mismatch, I had to make the front cross section larger in diameter so that the opening didn't just float in space. Because the cross section was larger, I had to add a polygon behind it to avoid being able to see through it from the front.

After a while, it occurred to me that with one extra polygon, I could improve the shape quite a bit. The front of the Intake is a 12 sided circle just like the opening. The transition to the 8 sided circle at the next cross section adds 2 Parts, but one polygon at the front behind the opening could be removed. Net is +1. The First Screenshot shows the result.

The Second Screenshot shows the Intake being cut at the separation line between the Nose and Fuselage groups. After a lot of experimentation, I believe that separating the Nose and Body,Main groups at 2.62F would leave the fewest bleeds.

Note that one additional row of parts needs to be added. This is not a total loss because the shape can be improved a little by reducing the cross section at 2.30F to 95% of its original size.

- Ivan.
 
Oil Cooler Components

The Oil Coolers were originally created as Structures because of a concern that there might be a shortage of Components. It turns out we have a few left over and the replacing the Oil Cooler Structures with Components improves the shape. (It also reduces the Parts Count!)

The First Screenshot shows a front view of the Left Oil Cooler Structure. With a Structure, The cross section must be in the list of available shapes. Here we used the Octagon.

Cross sections of the Oil Cooler are round, but part of this object recessed under the skin of the Cowl.

The Second Screenshot shows the Oil Cooler rebuilt as a Component and without the portion that sits under the skin of the Cowl. The Blue Outline Part is the edge of the Oil Cooler where it has been cut. Note that the highlighted point is on the rear of the outline.

- Ivan.
 
Reducing Parts

When I started this project, I was a bit overconfident and overly ambitious. One result is that although this aircraft looks pretty good in my opinion, I am running into hard limits regarding usage of resources.

The Parts limit on a AF99 Project is 1200. I have been around 1185 or so for quite some time with a few essential (in my opinion) pieces still unbuilt. I like to have Parts line up and meet at their vertices, but the reality is that even if they do not, often the difference cannot be seen in the visual model in the simulator.

The First Screenshot here shows the FuselageFor Component. My original intention was to have the Fuselage Parts line up with the Wing Fillet Parts. If I alter them so that they do not, I can save 3 Parts per side.

The Second Screenshot shows how closely aligned the Parts to be combined actually are. There will be no degradation in the visible shape of the joint between the Fuselage and Wing Fillet as a result of this change. This is a front view and as can be seen by the inboard and outboard lines, everything is vertical so there is no actual need to triangulate the Parts.

There are quite a few other placed this can be done. Always try the "No Visual Change" places first.

- Ivan.
 
Cowl Guns

The Nose section of most Aeroplanes is textured Left - Right. This makes it rather difficult to put a nice looking texture to represent Cowl Machineguns. To do this properly, an Insignia Part should be used to represent each Gun Trough and that part should be textured Top - Bottom.

As usual, the dimensions are gotten from the reference drawings. The back end of the Trough goes from 0.40 Feet to 0.70 Feet on each side. This location places the Trough Part over the Parts Nose02L02, Nose03L02, and Nose04L02.

What we need to create is a single slightly non-planar polygon (it can be non-planar because it will only be seen from the top) that is even with the surface of the three Nose Polygons it will overlay.

In the First Screenshot we are connecting the dots at each end of the Gun Trough to be able to locate the end points at the front and rear on a line that is ON the corresponding Nose polygon. This is a view of the Gun Trough and the Nose polygons from the front.

What is not shown is a periodic view from the top as we create this Part to confirm that the tape looks appropriate.

The Second Screenshot shows the result in the simulator.

The Resource Cost for these pieces was 4 Parts: Two actual polygons and Two Glue Parts.

- Ivan.
 
Nose / Wing Templates

AF99 has a feature by which a polygon is used to specify the viewing plane between the Nose and Wing. If we are in front of this plane, the Nose pieces are in the foreground. If we are behind this plane, the Body,Main and Wing pieces are in the foreground.

The First Screenshot shows how the opposite side Cannon Muzzle bleeds through the Nose group.

The Second Screenshot shows the Fore - Aft location of this Template. Note that it is a nice SHARP part and has sliced through the Wing Cannon and even the Pitot Tube and now Pieces of each are in the Nose Group and Wing Group.

The Third Screenshot shows a 3D view of how this Template is actually placed relative to the rest of the aeroplane.

The Fourth Screenshot shows the result in the Simulator.

This is the first time I have used this feature in a project and it appears to work exactly as advertised. There is one major characteristic to note though: Many other parts can be Mirrored without any issues to create an opposite side part. These templates have a specific function which is different from Left to Right.

- Ivan.
 
Tail Gear Part 1

Folks may have noticed that there have been Tail Gear Fairings, Wheels, and other various pieces shown in many earlier screenshots but there has not been a description of how they were created. That is because the final result was not entirely determined until now. There were not enough resources to be sure I could build what I had intended. As it turns out, with a bit of "Resource Reallocation", everything worked out.

The sequence of construction was to create the extended wheel, retracted wheel and the parts that were visible when everything was extended. Pieces were cut out of the Tail Cone to fit the new Pieces.

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Tail Gear Part 2

Once all the pieces were created, a non-intuitive sequence is used for assembly:

Note that the sequence starts at the Extended Tail Wheel with additional pieces wrapping around the Wheel. When the Tail Gear is finished, it attaches to the Tail Cone. The Tail Gear Doors were added to a cutout in the Tail Cone to address several bleeds.

Note that the Forward Piece of the Tail Cone along with the Head Rest, Antenna Mast and other assorted parts is put together as another cluster of well connected parts independent of the Aft Piece of the Tail Cone.

We rely on Automatic Glue to attach the two Clusters of Pieces with no bleeds.

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Tail Gear Part 3

These Screenshots show the Tail Gear Extended and Retracted. I can find no bleeds from this assembly sequece.

Another technique which is shown here is that of saving off the Project as a different AFA file (called Partial.afa here). The Center of Rotation has been moved in this Assembly to be centered on the Tail Cone and this makes it easier to observe the latest work from different angles.

Good Night.
- Ivan.
 
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