F4U-1 Structural Framework

[Ambaryerno]

I'm looking for good cross-section/blueprints of the F4U-1's structural framework for a 3D modeling project. There was a previous thread here a while back about it, but all the sources provided there are now defunct.

I've got good elevation drawings for the exterior shape, but nothing for the internal skeleton. Does anyone have scans/copies of the material cited in the old thread, or anything that would be of use?

 

[bse7entn]

AirCorps Library has become the go-to source. It will take some wading to find drawings for any specific block number you want to model but they have thousands of blueprints scanned for F4U.

 

[cvairwerks]

As Bse7entn said, join up at Air Corp. The fastest way to find if the drawings are in their collection, is find the part in the IPB and then it will give you the print number for the part itself, and usually, above that, it will be grouped under an assembly drawing. From there, you look in the print section or use the search box.

Basically, the IPB is a written parts tree, with an assembly being the highest branch, and then adding on sub-assemblies under it and each sub having it's own list of subs and so on, until you reach the final point of the individual parts themselves. Kinda racks the brain the first time or two you look at them, and each manufacturer does it slightly different, but you become accustom to it and can find things pretty fast.

 

[mjfur]

http://www.scharch.org/Ed_Scharch/usn-aircraft/F4U-Corsair/dwg-Cutaway-F4U1D.jpg

F4U Corsair - Blueprints, Drawings & Documents | AirCorps Library

F4U FG1 F3A F2G Goodyear Brewster Chance Vought Corsair

app.aircorpslibrary.com

 

[Ambaryerno]

As Bse7entn said, join up at Air Corp. The fastest way to find if the drawings are in their collection, is find the part in the IPB and then it will give you the print number for the part itself, and usually, above that, it will be grouped under an assembly drawing. From there, you look in the print section or use the search box.

Basically, the IPB is a written parts tree, with an assembly being the highest branch, and then adding on sub-assemblies under it and each sub having it's own list of subs and so on, until you reach the final point of the individual parts themselves. Kinda racks the brain the first time or two you look at them, and each manufacturer does it slightly different, but you become accustom to it and can find things pretty fast.

Looking through them now, but woof is this overwhelming, especially with what I'm trying to do. I may need a translator because some of this I'm not even sure what I'm looking at (and many of the drawings are so faded they're not even readable). There's definitely some really cool stuff in here that will be useful I never even considered (placards, etc.).

 

[cvairwerks]

Ambaryerno: I'll see if I can find a very small assembly this afternoon and walk you thru the tree. Once you see how it works, it gets much easier. Where it does get complicated is when assemblies are similar, but not identical and are effective for specific serial number aircraft.

 

[Ambaryerno]

Ambaryerno: I'll see if I can find a very small assembly this afternoon and walk you thru the tree. Once you see how it works, it gets much easier. Where it does get complicated is when assemblies are similar, but not identical and are effective for specific serial number aircraft.

Thanks, I appreciate it. As far as differences in assembly, I'm primarily looking at the first batch of F4U-1s that actually made it into combat, with later modifications to follow.

 

[cvairwerks]

Going to try this, but don't know if it will work correctly...

This is Figure 16 on the right side page. If you look at item #1, it's listed as Plate Assembly, Center Hinge, Left Aileron....
It's part number is VS-19835.
It's made up with a VS-19835-1 Plate, 5 each AN367-F1032 nutplates and 5 each CVC-3007-1 Gaskets

So, simplifying it, without all the other info it works out to looking something like this:

VS-19835
VS-19835-1
AN367-F1032
CVC-3007-1

This repeats for each assembly in the section. Where it starts getting complicated is when you have multiple assemblies and part number or dash number changes in there, that are effective for only certain s/n aircraft or series. Without copying more pages, if you are looking at the IPB and flip to Figure 18, for p/n VS-10022, it has a note (a) that says that from a/c 50560 and subsequent, the updated part is VS-38022.

It gets a little easier to follow when you spend some time in the books chasing part numbers.... plus over 40 years doing it helps

 

[Ambaryerno]

So this is more along the lines of what I'm needing:

Something I can import into Blender as a background image:

The other could help with how the various parts go together, but not with actually modelling them.

 

[bse7entn]

Something I can import into Blender as a background image

I'm very familiar with this. How familiar are you with blueprint reading? How detailed are you planning to go?
This takes some up front planning, otherwise there's a good chance you'll get in the weeds and have to course correct mid project. Not insurmountable but better to avoid.

Also you have to pay attention and consider how the digital scans were created. The blueprints were photographed onto microfilm, then scanned. Not all the blueprint pages were perfectly planar to the camera. Sometimes there's a bit of skewing. Some aren't exactly proportional to themselves. Many have a slight rotation, like .2° (sometimes more). Depending on how detailed you want to go, you really have to rely on the measurements on a sheet and not just tracing over the lines until you check the scaling (vert and horiz) of your imported image. You could end up with parts that don't line up. In the case of arresting hooks and landing gear this could be a big deal.

If you have any questions I can try to help.

 

[cvairwerks]

What you have there is an assembly drawing. It shows what parts go into the assembly and how they are attached. You most likely need to drill down to the detailed part drawings and would have to build the individual parts up into the assembly.

 

[cvairwerks]

Bse7entn can be more help than I, on doing the 3D stuff. The last time I did any, was on Mechanical Desktop 3.0 and Catia 5, probably 25 years ago.

 

[bse7entn]

Bse7entn can be more help than I, on doing the 3D stuff. The last time I did any, was on Mechanical Desktop 3.0 and Catia 5, probably 25 years ago.

Possibly but the experience in parsing the information is what allows one to model correctly. I only have about 8 years in aircraft blueprint reading myself. I'm sure I could learn quite a bit from you on that front.

 

[Ambaryerno]

I'm very familiar with this. How familiar are you with blueprint reading? How detailed are you planning to go?
This takes some up front planning, otherwise there's a good chance you'll get in the weeds and have to course correct mid project. Not insurmountable but better to avoid.

Also you have to pay attention and consider how the digital scans were created. The blueprints were photographed onto microfilm, then scanned. Not all the blueprint pages were perfectly planar to the camera. Sometimes there's a bit of skewing. Some aren't exactly proportional to themselves. Many have a slight rotation, like .2° (sometimes more). Depending on how detailed you want to go, you really have to rely on the measurements on a sheet and not just tracing over the lines until you check the scaling (vert and horiz) of your imported image. You could end up with parts that don't line up. In the case of arresting hooks and landing gear this could be a big deal.

If you have any questions I can try to help.

Basically something can could conceivably be used for DCS or another sim.

I have some fairly accurate plan drawings of the completed aircraft to model the general shape, (though there's some discrepancies between views) but that doesn't help for places where, say, the ribs and stringers are visible, (landing gear bays, cockpit, front cowl) or complex areas like the folding parts of the intercooler door. And I presume the framework will need to be modeled to SOME extent.

What I've got so far:

In "salmon" as I believe that's appropriate.

I'm currently working on cleaning up the rear window cutouts on the turtledeck (one of the spots the plans didn't quite match between the side, dorsal, and section views). Some of the hard angles aren't in for the SubD modifier, yet. I haven't done the root for the vertical stab yet. I'm trying to get everything that's mirrored port/starboard first since the stab is offset.

 

[cvairwerks]

Basically what you need right now is what is known as OML data....Outer Mold Line. It's the surface descriptor for the outer surfaces. Unless someone has built an OML table, and that would be hundreds of pages of coordinates, you would need to build a wire frame off of individual bulkheads and ribs and then surface the frame.

 

[cvairwerks]

Just to give you an idea on how big an OML table would be, the one for the F-16 is about 3" thick and printed double sided on the paper.

 

[Ambaryerno]

That's more or less what I did.

I started with the wireframe on the sections you see hereand went from there.

 

[bse7entn]

Basically something can could conceivably be used for DCS or another sim.

I have some fairly accurate plan drawings of the completed aircraft to model the general shape, (though there's some discrepancies between views) but that doesn't help for places where, say, the ribs and stringers are visible, (landing gear bays, cockpit, front cowl) or complex areas like the folding parts of the intercooler door. And I presume the framework will need to be modeled to SOME extent.

What I've got so far:

View attachment 828696

In "salmon" as I believe that's appropriate.

I'm currently working on cleaning up the rear window cutouts on the turtledeck (one of the spots the plans didn't quite match between the side, dorsal, and section views). Some of the hard angles aren't in for the SubD modifier, yet. I haven't done the root for the vertical stab yet. I'm trying to get everything that's mirrored port/starboard first since the stab is offset.

Understood. I haven't studied Vought drawings or even F4U specifically. My current understanding is the salmon is for structure on the early "birdcage" Corsairs. I'm not sure how much of that would extend to any skin, if it did would be on the interior side.

Have you looked into polygon limits for what DCS or flight sims need? That will help you develop a plan for the model.
Depending on how precise you want, be careful to not just mirror everything. 3D modelers are kind of trained to mirror a lot. Aircraft tend to be only mostly symmetrical. A vent on left wing but not right. Pitot tube on right wing but not left.
Most models I've seen tend to skimp on areas that wouldn't typically be seen, such as wheel wells, even if they are exposed. It's a lot of work and time for less payoff.

Modeling from views like that will get you in the general neighborhood of the aircraft silhouette but definitely will lack in accuracy. Tagging onto what C cvairwerks said modeling bulkheads and stringers will get you much more accurate skin. Even if it's just outline shapes versus modeling a full bulkhead. (Bulkheads are NOT simple)

Here's what I'm currently working on for an AT-6D. My use is more involved than a flight sim but it illustrates the idea.

 

[cvairwerks]

FYI, if you really want to see some good F-4U stuff, pull up everything on Vulture's Row Aviation, over on youtube. Chuck is restoring at least one bird right now. There have been a couple of different youtubers that have visited his shop and shot video.

 

[Ambaryerno]

I think the salmon has turned up in restorations, too. It wasn't until the 1As started to roll out that they stopped tinting the chromate like that.

I looked up a couple models on DCS, and the F-14 apparently hits 2 million triangles including the cockpit.

The mirroring is just to get the basic shapes. After I get that I'll be applying it so I can do the asymmetrical stuff.

And this STILL brings me back to the original point of my post: Trying to find good drawings of the bulkheads, ribs, and stringers that would be useful references for modeling.