Need for Research

[Seagull V]

Accuracy of Drawings.

Many years ago I spent many hours in my then favourite hobby of plastic modelling.

A very well respected member of that community did an article on the P-51D Mustang comparing different models and different drawings.
There were quite a few differences between them, now you would think that aircraft like the Corsairs and Mustangs would be very well documented,
but it appears that different people use different sources.

People who do colour side profiles often start with borrowed drawings so unless you know that they are meticulous with their own research for that
profile be careful about using it. Also I have seen different colour profiles of the same aircraft with different colours.

As a general rule I look for 3 different sources and compare them, if there is still no consensus of agreement between them I look at as many photos
of the period aircraft as possible to compare the drawings with. Photos in the old days were often airbrushed so that is always something to consider as well.

Finally, you have to be happy with what you are doing, as well as remembering the learning curve that you started with.
My first plastic model aircraft was a Grumman Avenger and from memory the wings were on back to front with more glue on the transparent canopy then there was plastic, but hey I was proud of my work back then.

Enjoy your previous work - if you want to do a rebuild/new one then get the resouces to a point that you happy with and build away.

Regards, SG

[Ivan]

Hello Hubbabubba,

Thanks for the vote of confidence. The problem here is that I can't find ANY set of drawings that I consider "reliable" any more. They are all starting to look bad. I know there are problems with the shape of "My Corsair" and will be addressing at some point. I believe there IS such a thing as the "Perfect Corsair" in that it would match the manufacturer's blueprints. I know I won't get there because with AF99, you really can't within the resource limits. Still, I would like to know what one is supposed to look like. I had thought that mine was overly fat, but the more I look, the more reasonable it appears. There are still a few things wrong, but I haven't quite figured out what those things are yet.

I read the book "Whistling Death" by Boone Guyton quite a few years ago. It is excellent. The differences he describes though are mostly in detail and installed equipment. We don't have enough detail in a CFS aeroplane to represent that kind of stuff.


Hello Seagull V,

I also used to do a fair amount of plastic modelling. I still do with GI Joes, but don't build much in the way of airplane kits. Most of what I built was either 1:72 or 1:48. In the Corsair line, I still have a Monogram F4U-4 in 1:48 and a Ertl 1:72 F4U-1A or -1D. The Monogram seems to have a decent shape. The Ertl plane is too long and thin and it is a nice looking plane despite my work. It does however have a lot of incorrect details for a Corsair. I still have a few more kits that I have not built. There are a couple Hasegawa 1:72, an Arii 1:48, a Revell 1:32, several Monogram 1:48 and probably a few more I haven't seen in a while.

Regarding looking at photographs, I have looked at several hundred within the last few weeks and gone through at least 4 books on my shelf: Squadron Walkaround, Squadron In Action, Motorbooks, WarbirdTech and a couple I can't remember offhand. All I can say is that this critter is TOUGH to pin down.

I am tending more toward a rework of a few critical places on my CFS aeroplane rather than a complete build from scratch these days. It seems like the more I look, the less I see really wrong with the general shape.

Check out this overlay comparison with an actual photograph. It is difficult to find a good profile photograph, but this one isn't that far off. Note that the differences between my 3D Model and this photograph shows differences in different areas than the last two Overlays???

- Ivan.

[Seagull V]

Side profile & mesh looks pretty good, a smidgin out in a few places - but I would be happy with that.
Wings look a bit out, if you move those a bit in AF99 you should have a nice model.

Will have a look at my references that I can dig out of my boxes, will let you know if I find anything usefull.

Regards, SG

[Ivan]

Hello Seagull V,

I just tried yet another reference: Squadron's Detail & Scale book on the early Corsair. This is the result of yet another overlay. The wings don't look quite as far off on this one. The claim for these drawings is that they were done with reference to factory dimensions and blueprints.

I personally am not so sure any more. I believe the photographs are the definitive reference, but even they are not consistent. Note that there are Corsairs that appear to have a slight hump about where the Aft Antenna Mast meets the Spine. Note also that the -1D Corsair at Udvar Hazy does NOT have this spine.

Am I really the first person to compare these drawings with actual photographs???

(Yes, I posted another image. Brave, aren't I?)
- Ivan.

[Ivan]

From an Eyeball check of my Corsair, the cowl opening apears too large. The relatively small appearance of the cowl opening is what struck me first when I first saw the F4U-1D Corsair out at NASM Udvar-Hazy.

A couple weeks ago (starting before my vacation), I had started to look for photographs with a front view of the Corsair cowl. I downloaded a few and did a pixel count to compare the diameter of the cowl overall in comparison to the diameter of the opening.

Last night, I did a comparison of these numbers with the cowl radius of MY Corsair. Here are the rather surprising results:

The Cowl of my Corsair has a radius of 2.48 feet at the back and 2.41 feet at the front before the rounded section to the opening. The opening itself is 1.90 feet in diameter.

Because I often can't tell if the pixel count of the photograph is of the large diameter or the smal diameter, I used both for calculations.

The range appears to be from 1.83 feet minimum to 1.96 feet maximum. The numbers (High on one side and Low on the other) appear to show 1.89 feet and slightly over 1.90 feet which is dead on for what I had built.

Now if this is correct, then why does it look wrong?

- Ivan.

[Ivan]

This overlay shows the greatest differences.

- Ivan.

[Ivan]

From the overlay above, the size looks generally pretty good. Note that there are differences between the Propeller Blur in my 3D Model and the Propeller Arc in the colour picture. There are differences in the Propeller diameter between different models of the Corsair. The Wing Tip was missing in the Colour Drawing and I pasted a reflection of the opposite Wing Tip to correct that issue as well as rotated it by a couple degrees so that the Wings were level.

The "Big Difference" is that the Wing on my model is almost exactly 3 inches too high and there are notable differences in the Wing Root area which I may continue to ignore in an updated model.

I believe I have also figured out the "Hump Back" profile that is shown in some photographs and drawings. It exists because the Fuselage Spine has a slight parallel section on the sides though not the top so that the Canopy can fit over it when it slides back. If the photograph is taken from above or significantly below the aircraft's horizontal center line, it shows up. In a strict Profile shot, it doesn't show up.

- Ivan.

[Ivan]

In order to shift the whole AF99 project a bit, I have done a fair amount of programming.
The single AF99 Parts have been addressed.
The program I wrote for this purpose years ago is called "MoveIt".
Recently I wrote another program called "StructMoveIt" that shifts a AF99 Structure Fore and Aft.
This is all that is really necessary for the AFS file. The Templates get moved around using "MoveIt".

After all the pieces are moved around, the textures will not line up.
The latest program I wrote is called "MoveTexture" and edits the AFA project file to shift the values used to overlay textures.

Screenshots attached show that currently the textures don't line up. That isn't very pretty, is it?

Note that the AIR file will need modification as well because things like Gear contact points and Cockpit view points need to agree between Model and AIR file.

- Ivan.

[Ivan]

A little more tweaking of the program and I got the Top and Side Textures lined up.
Correcting a very silly bug and the result is a program that will move ALL the textures to their appropriate places as can be seen in the last screenshot.

To Summarise:
At this point, I have a set of utilities that can shift the CoG of a AF99 project in a matter of a few minutes.
This allows for very easy correction of a project at its basics rather than using the Offset method.
I am sure you folks know of a few projects out there that don't look all that bad but just have their CoG incorrectly located.

Good Evening.
- Ivan.