Raptor 3D Project - Edits 04

The Wings... A tricky proposition.

The F-22 wing is interesting, and I haven't figured it out yet. In the front view drawing, the wings look as if they are bowed downward, like kind of a curved anhedral. When you look closer, you can see that the leading edge is NOT curved, but the trailing edge has something odd going on. You'll see how tricky it is, in the following images.

First, I simply extruded a thin airfoil, using only a root and tip section, and used the "red glass" shader on it, so I could match up the proportions with the drawing below. I can make the "cut" at the tip later, once I have more information on the other problems.

I positioned some markers (blue) to show me where the control surfaces are, in the top and front view.

Some of the other alignment aids... (See below)

The image above shows several things I've used, to figure out the wing shape:

My temporary wing, with the "red glass" shader, so you can see the drawing behind it
A general horizontal (RED) centerline (on the drawing) that runs from the center of one wing tip to the opposite one
A (GREEN) line that shows the centerline of the leading edge flap
A (YELLOW) line that's aligned with the part of the trailing edge that's visible
The current "stats" for this setup. (More on that, below)

By this point, I'd collected 300 photos from the net, (which eventually grew to over 500) the Lockheed-Martin drawings, and some experience designing aurcraft models, yet I haven't been able to really put together what's happening with the wing. I'm convinced that the wing has some aerodynamic "twist", or "washout", and somewhere around 3 degrees would be typical for that. The wing may also have a slightly positive or (more likely, negative angle of attack at the root, where it joins the fuselage. I've tried extreme amounts of twist, up to 5 degrees, to produce something that matches the drawing, but so far, no match. The wing also appears to have some overall anhedral. Since the arrangement I'm trying here doesn't produce results that match the drawing, I have more work to do.

I'm investigating the idea that maybe the wing twist and/or anhedral doesn't start at the root. Perhaps it doesn't start until somewhere close to where the flaps end and the ailerons begin. I'm also having to guess about the thickness of the inboard and outboard airfoils, using the drawing as a reference. (The front view shows the odd "bulge" you see, but the side view shows a very thin wing. Usually, I can figure these things out in a few minutes, but this one is tricker! Every wing and tail edge on the aircraft has a beveled treatment that hides the actual airfoil shape, and makes all the surfaces appear thinner than they actually are. (This area is painted a lighter color on the actual aircraft.)

A different approach to the problem...

Most of the time, I build actual airfoil shapes for my aircraft, beginning with an extrusion (span-wise) and adding details later. That doesn't seem to be working yet, so I may try building the wings from the inside out, by using the cross section scans from the plastic display model I mentioned earlier.

The nature of these cross section scans is that they're not high resolution. That makes them impossible to simply "skin", as they stand now. But they do provide a reference that will be helpful in figuring the wing out, because they seem to be the correct shape.

The position of the slices (front to rear) on the original plastic model were spaced evenly, but otherwise a bit random. This was only done as a demonstration of the technique, and not to actually build the model. Now, that model (Revell's 1/48th scale F-22) is discontinued. (!) So, I'm a bit limited as to this kind of resource, and wish I had a higher number of higher-precision slices. (If you have one of the Revell 1/48th scale F-22 kits in the box, email me!)

The slices, scanned.

The slices, with my temporary wing in place. (in progress)

Surprise! Any easier solution than I would've guessed:

My test wing had wing twist and anhedral, but wasn't the right shape, overall. (not referring to the tip... I'll cut that angle later.) But I noticed that when I inserted the "spars" I made from the Revell model scans, there were only subtle differences. Hmm...

Checking the fit with the fuselage top

Checking the fit with the fuselage bottom

On a whim, I did a boolean "union" of my test wing and the spars. (next two images) I was pleasantly surprised to find how closely the parts matched. The spars didn't have enough detail to make wings, and my test wing wasn't quite right, but combined, this is an editable part, and a much easier way to go than starting from scratch. (and when finished, more authentic)

The merged parts, rendered (front)

The merged parts in wireframe (rear)

A little refinement on this idea:

There is some excess material resulting from combining the parts, and most of it is near the wing root, in the form of the "fairing" section with the fuselage. If I'm willing to do that fairing later, (which I am) then I can make this wing editing job easier, by reducing some of that excess. So, I edited the "insert" that was made from the Revell "ribs", so that only the important areas of the outboard wing will need to be edited. Here are the simpler results.

The only part used on the bottom of the wing is a marker for where the aileron actuator fairing goes.

The important missing parts of the top wing shape.

The merged parts in wireframe (top)

The merged parts in wireframe (bottom)