F4U-1 Structural Framework

[bse7entn]

Don't get discouraged. Guys building planes might not get back right away. Just make notes and move on to something else.

 

[Ambaryerno]

Been a while, so thought I'd post an update on how it's going:

View attachment 877439
View attachment 877440
View attachment 877442

The first assembly, 10228 for the earliest Corsairs, has been completed (I've turned off rendered mode for the panels, which show up better this way). To make the most comprehensive model possible, I'm now working on the first turtledeck revision (sub-assembly 19381) as part of the full assembly for aircraft 325+ and the FG-1s and F3A-1s, (19378) but I was surprised to see that even though the window tunnels are blocked off by the new armor plate, it still retains the windows themselves. Were these only faired over in the field prior to the final turtledeck revision?

 

[cvairwerks]

Been a while, so thought I'd post an update on how it's going:

FYI....The permissions to view the attachments are all turned off...

 

[Ambaryerno]

Not sure what happened, try again now.

 

[Ambaryerno]

I'm taking a break from the interior structure of the model to get the fuselage contours down, however I'm run into a snag.

I have everything from station 100 aft, (except some parts of the tail hook notch and end cap) the cowl lip, and the cowl panels. I haven't worked on the cowl flaps at all but the drawings for those are pretty clear.

The problem is the diaphragm shoulder at the front end of the accessories compartment (station 54 1/8). There are two copies of the drawing, VS-13316, on Aircorps Library. Both are almost illegible.

Does anyone know the measurements for this part? I think that's all I need to finish roughing out the fuselage contours, because I believe it transitions directly to stations 91 3/4 and 100.

 

[bse7entn]

If you take a copy of the dwg into your image editing program, invert the image and you can see the details a lot better. Add a Levels or Curves adjustment and you can get a bit more info. It doesn't make everything super clear but it does help a lot.

 

[Ambaryerno]

Yeah, I've done that. The only actual useful data that I can get is that the very forward lip ends at station 47 13/32, with the cowl flaps overhanging that by about an inch to station 48 13/32. There's two references that are measurements "To <Something> Ref" which I presume is the horizontal reference line. One looks to be 24in from it, and the other is 14in, but I can't tell what it's actually measuring

I also see where the segments are of each of the labeled contours are (15 degree intervals) but there's no actual radial measurements that I can see. But I can tell it's not symmetrical and each segment is different.

 

[bse7entn]

I figured you probably did but we're troubleshooting, so just establishing a baseline.
Front view labels horizontal line as CL THRUST (REF).
The Contours diagram is measuring off that: 24 TO TL (REF.)
with TL probably abbreviation for Thrust Line.
It's really hard to make out but I think both measurements read 24. At a glance it makes sense the contour narrow openings top/bottom are symmetrical unless you see a reason in other drawings why that shouldn't be.

 

[Dana Bell]

You mentioned that your drawings will cover the early airframes, which means there should be a Molins signal flare discharge port in the upper left-side fuselage, just aft of the cockpit. The hole was covered with a doped fabric patch until the Molins was fired, but (in the field) was rarely repatched after that. I'm working away from home just now, but I believe I've an early inboard profile that show the location - not much help, but at least a start if you want to include the feature in your search.

The Molins was dropped fairly quickly, and it rarely shows up in drawings, but you'll notice it in photos.

Cheers,



Dana

 

[MIflyer]

In case you don't have these.

 

[Ambaryerno]

I figured you probably did but we're troubleshooting, so just establishing a baseline.
Front view labels horizontal line as CL THRUST (REF).
The Contours diagram is measuring off that: 24 TO TL (REF.)
with TL probably abbreviation for Thrust Line.
It's really hard to make out but I think both measurements read 24. At a glance it makes sense the contour narrow openings top/bottom are symmetrical unless you see a reason in other drawings why that shouldn't be.

Which in the -1's I believe that's roughly to the horizontal center, since it wasn't until the -5 that the thrust line was angled downward.

So is that 24in to 47 13/32, or to the outside at frame 54 1/8?

 

[Ambaryerno]

In case you don't have these.

View attachment 900082View attachment 900083View attachment 900084

Yes, I've seen them. They're great as a general reference, but not so much for actual modeling since none of them provide actual measurements.

 

[bse7entn]

Which in the -1's I believe that's roughly to the horizontal center, since it wasn't until the -5 that the thrust line was angled downward.

So is that 24in to 47 13/32, or to the outside at frame 54 1/8?

Should be a radial measurement from center, no?
This measurement still is weird. I'm not exactly sure what it's measuring because it doesn't intersect with the contour opening.

What I would do is draw separate Curves for each contour. Label them accordingly, and place them radially in your scene where indicated from front view.
Then you start to build a frame work for how it should look, fill in with your favorite method.

 

[Ambaryerno]

Should be a radial measurement from center, no?
This measurement still is weird. I'm not exactly sure what it's measuring because it doesn't intersect with the contour opening.

What I would do is draw separate Curves for each contour. Label them accordingly, and place them radially in your scene where indicated from front view.
Then you start to build a frame work for how it should look, fill in with your favorite method.

That's assuming the drawing itself is actually accurate to the intended measurements, which I've found most of the time is not the case.

 

[bse7entn]

That's assuming the drawing itself is actually accurate to the intended measurements, which I've found most of the time is not the case.

Yeah I understand. Between errors in drawings, any possible skewing of the microfilm camera not being perfectly planar to the original drawings, and any possible smearing/stretching during the scanning process; there are several variables working against you. The other recourse for checking your work would of course be modeling the underlying structure. Honestly I think whatever you do will be fine since you're in a polygonal workflow and not CAD.

Everything is looking really good so can't wait to see more.

 

[Ambaryerno]

Yeah I understand. Between errors in drawings, any possible skewing of the microfilm camera not being perfectly planar to the original drawings, and any possible smearing/stretching during the scanning process; there are several variables working against you. The other recourse for checking your work would of course be modeling the underlying structure. Honestly I think whatever you do will be fine since you're in a polygonal workflow and not CAD.

Everything is looking really good so can't wait to see more.

Unfortunately, the underlying structure says to use the same loft templates as the skin that don't exist.

 

[bse7entn]

Reads paper: "See other side"
Flips paper over: "See other side"

Because of course it does.

 

[cvairwerks]

Take a look at VS-24321 and you may be able to back into the measurements from there, by bouncing back into assemblies that attach to the 24321 and have to match the contours. 24321 was a direct replacment for the 13316.