The Lightning looks a bit nicer now with actual textures on the wheels.
Next are a couple experiments with adding new textures and then scribing panel lines.
Hi Ivan,
OK, I´ve seen that.
Apart from pieces disappearing, I also remember some graphic interferences in the shape of triangles that I didn´t know the origin of.
On one occasion this happened to the shadow of an Ekranoplan (the Caspian Sea Monster, a huge Russian ground-effect vehicle) I built: The craft´s tail extended beyond an AF99 maximum-size limit (which is not mentioned anywhere). Instead of re-building everything I moved the CoG backwards so that the whole machine came forward, and that cured it.
Cheers,
Aleatorylamp
P.S. Your Lightning is certainly looking smart - a nice build!
The model in my previous post didn't have any aberrations so I decided to try to texture the Control Panel.
The result showed without a doubt that I had already reached the limit.
This time there were no polygons stretching off "To Infinity and Beyond!"
Instead, there were just a couple missing polygons from the Starboard Cowl....
....AND a very strange looking little textured polygon on the outboard side of the Starboard Cowl.
The texture on it doesn't obviously match anything else on any of the texture files
And the textures on it change shape as the polygon nears the edge of the screen.
Undoing the Control Panel texture restored the model.
The differences between an early production Lightning (F model in this case) and the J-L models are not great from a visual standpoint.
I believe the differences to be the following:
1. Side Hinged Canopy versus Rear Hinged. Some F models had the rear hinged version. In any case, the visual differences are very slight.
2. Armour Glass on the front Windscreen. There are some noticeable differences, but the version I modeled is a bit of a compromise anyway.
Now for the Obvious Stuff:
3. Earlier Lightnings did not have the Center Frame at the rear of the canopy. There appears to be an internal brace instead.
4. Coolant Radiators are a radically different shape. They are much higher and narrower.
5. Intercoolers were located in the Wing Leading Edges so there was not a large scoop under each engine cowl.
6. There was a gap between the Exhaust Plenum and the Turbocharger on each side. The earlier model was hidden under sheet metal.
The screenshots show my first attempt at Coolant Radiators for the Lightning-F. From most angles, they look narrow, but actually match photographs pretty well.
Unfortunately there are not many photographs of early model Lightnings except for Glacier Girl which is a P-38F-1-LO.
One of the biggest problems with building a Radiator for the F model Lightning is the inability to find good detailed drawings. Photographs are also hard to come by if they are not of "Glacier Girl".
Because of those issues, the new Radiator was built mostly by eyeball with as many photographs as I could find but all the large photographs are of Glacier Girl.
While I believe that Glacier Girl is a very pretty restoration, just about everything was rebuilt rather than original, so I do not have as much faith in the contours of the sheet metal. Unfortunately, there are no other early model Lightnings flying today and even photographs of static displays are hard to find.
The Radiator shown here is actually a touch wider than the last one but note that it is still much narrower than the one for the J model.
Attached are screenshots of the Lightning with an early model Radiator on the Port Side and the late model Radiator on the Starboard side. They look about right to me, but I make no great claims to accuracy because of the "Eyeball" measurements.
Please feel free to comment if you see inaccuracies.
The Cowl area was modified over the last few days and along with the Exhaust Plenum and Canopy Frame pretty much concludes the planned modifications to build a P-38F.
The conversion considerably reduced the Parts count in AF99; The F model is at 1127 Parts which is almost 50 below that of the J model.
Most of the difference is in the Coolant Radiators but the Cowl area is also much lower. Both are also much lower in complexity.
One of the most difficult Parts to build was the Intake Opening for the Oil Coolers which needed a lot of adjustment to match the bottom of the Cowl.
Looks like this project is coming along very nicely indeed! Your intuitive "eyeballing" definitely looks accurate, and as always, I´m impressed by your admirably clean clean construction technique.
I´m also looking forward to the future section of your P-38 tutorial when it comes to texturing it, for more details on how to divide texture bitmaps for use on more than one part.
So far, I have had success in using only 1 texture instead of 4, for biplane wings with roundels on upper-top and lower-bottom wings only, by using convenient sections of the bitmap. I have also done this on triple fins with roundels only on the outer sides of outer fins, with only 1 texture instead of 3. However, a different matter is combining 1 texture bitmap for wheels facing sideways and 2 pilot´s heads facing in opposite directions, which I haven´t figured out yet. Anyway, further development on the Lightning will definitely be interesting!
Incidentally, re. our previous comments on twin-boom/twin-fuselage types: Maybe as the P-38 has its engines on each boom/fuselage, it would qualify as a twin-fuselage rather than a twin-boom! Thus, a twin-boom would then be one with a single engine on the central cabin-pod, which would then be called the fuselage...
At the moment I´ve resumed construction of the Curtiss-Wright AT-9 Jeep, and I was wondering if I could use your Lightning .air file to adapt it to the dimension and power specifications of the Jeep.
It was rather hotrod, and I´ll be opening a separate thread for its construction and its impressive yet unstable flight dynamics, for which I will need some assistance on your part, if you would like to participate!
Actually the texturing on the Lightning was done some time ago starting at Post #72.
That is how it changed from multi-coloured to a uniform light gray.
Even the significant mapping scales I used are shown in the posts following.
Panel Lines are just another paint job and I really hate doing those, so that may take a while.
That is also why I chose to rework the model to a P-38F instead of doing any painting.
Smilo might have wondered why I didn't use the Lightning as a texturing tutorial subject.
The simple reason is that the Lightning is a horrible subject for a texturing tutorial because it doesn't encourage or reward a consistent texturing scheme.
If you look at how many pieces of the Lightning have paint detail or panel lines that extend across multiple pieces, the answer is "almost none".
The only area I can think of that requires a matching scale is the front and rear halves of the Nacelle and that isn't even a strict requirement.
There are no patterns that go from one Boom section to another and although I textured them to a common scale, I didn't need to and it will never show.
It is just a consequence of my obsessive nature and there was no real benefit to doing it that way.
You are welcome to use the Lightning's AIR file for your purposes, but the only useful thing it will give you is the extra engine.
Even THAT won't be very useful because your AT-9 Jeep didn't have counter rotating propellers.
If you need help on the flight model, just ask.
I hope Hubbabubba will see this message because he had planned to build the WW2 Trainer Types starting with a Texan / Harvard.
The AT-9 doesn't look like a simple project, so perhaps adding in two pilots would be a bit ambitious within the limits of AF99.
I CAN warn you about one thing:
With a single engine aeroplane, the Propeller effect on the rudder is predictable.
As soon as you go from one to two engines, the effect goes away entirely!
That is why on both my B-25 Mitchell and this Lightning, the Nose Wheel is made steerable even though the real ones were not.
You would figure that with Rudders directly behind the Propeller on both machines, the slipstream effect should be pretty good, but that is not how CFS AIR files work.... <sigh>
So.... The choice was either a steerable Nose Wheel or pretty much no low speed directional control on the ground.
Although no bombs are listed, the weight of Drop Tanks may bring the Gross Weight up to 19,800 pounds.
Since we cannot carry drop tanks, we will substitute bombs for the extra disposable weight.
Apparently the early F models were all pretty close to 13,300 pounds.
The P-38F had a Tactical Empty Weight of 13,200 pounds
The P-38F-5-LO had a Tactical Empty Weight of 13,400 pounds
The P-38F-13-LO, P-38F-15-LO and P-38G-15-LO were all back down to 13,300 pounds.
The other G models were back down to 13,200 pounds.
The differences appear to be Armament and Armour weights.
The P-38F used Allison V-1710-49 and V-1710-53 (F-5 series) engines.
(The Right Hand and Left Hand Rotation engines were different model numbers)
There was no provision for War Emergency Power.
Maximum (Military) Power was 1325 HP @ 15,000 feet using 47 inches Hg.
This Manifold Pressure could be maintained up to 30,000 feet.
This power output is a bit below that for the J model which had a Military Rating of 1425 HP and a War Emergency Rating of 1600 HP.
The early model Lightnings had less maximum speed but cruised a bit faster because apparently the new Radiators and Intercoolers added quite a lot of Drag.
Engine Tuning turned out to be fairly simple.
After adjusting the maximum Manifold Pressure down to 47 inches Hg, Friction and Supercharger settings were also lowered a bit and the results are close enough to satisfy me.
Sea Level Speed is now 335 MPH with 1260 HP. (Take Off Power should be 1240 but with only 44 inches Manifold Pressure)
Maximum Speed is now 414 MPH with 1316 HP at 25,000 feet
Maximum Speed is also 414 MPH with 1484 HP at 17,400 feet. This is way too high but is a consequence of how CFS handles superchargers.
Service Ceiling is just a touch over 40,500 feet with 50% fuel which is about where I wanted it.
Maximum speed is 5-10 MPH above were I wanted it, but is in the right range according to various sources.
Coefficient of Drag is unchanged from the J Lightning, but cruising speed at the same throttle setting should still be higher because the engine output will be a bit higher with the same Manifold Pressure due to the slightly reduced Friction values.
Screenshots show a bit more of the new Cowl from below.
Hi Ivan,
Sorry, with all the to-and-fro on other things I forgot I hadn´t answered your post below on this thread.
It will definitely be very interesting to see the differences in performance of the P38F in the .air file. I´m looking forward to that.
At the end I followed your suggestion on the .air file not really being useful for the AT-9 other than for its being a twin-engined machine. The two pilots within the AT-9 do make the cabin interior difficult with only AF99 as well, but we are dealing with that.
Cheers,
Aleatorylamp
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