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FTFC19 Tron Legacy One-Man Light Jet by DamoRC

DamoRC

Well-known member
Mentor
#1
Introduction and Inspiration

Tron Legacy was released by Disney in 2010 but I did not see it until early this year (better late than never I suppose).
I do remember watching the original Tron movie in the early 80s and, like many folks, being in awe of the incredible computer generated graphics. Of course they would be laughed at today.

tronbdcap1_original.jpg



I love the second movie and its a shame that Disney seemed to have canned the idea of a third. Obviously, the scene where C.L.U., Rinzler, and some hench-pilots in One-Man Light Jets chase the Flynns and Quorra in their Three Man version is one of my favorites and I became fascinated with the One-Man plane. I simply love the design and structure and am keen to see if I can make and fly one.

The vehicles for Tron Legacy were designed by a guy called Daniel Simon and technically, I should be calling it the "Single Light Jet" based on his title for the craft. The following images are linked through his website.







Daniel's images are wonderful and are really useful for working out some of the details of the craft, how some of the entities are joined, how the shadows show where the curves live etc.

Goals for the Project
Okay, the obvious is to build it, make it look cool, and fly it.

But there are a couple of challenges that I think will be interesting to deal with.

The first is the fact that the wing is not mounted to a fuselage per se. Instead it is mounted to the v-tail via pylons. In my best attempt I would like to replicate this feature without cheating.

The second challenge is that the way the plane is structured, there is almost nowhere to add weight in front of the CG. The only viable option is to have the weight (in the form of batteries, electronics, or dead weight) added to the front of the pylons. Looking at the plan view I think I may have to extend the pylons forward to make this approach work. Also, if I intend to put batteries in the pylons, then the minimum pylon diameter will need to be in the 2'-3' range and to keep the pylons even close to scale will require a pretty big build.

That's it for now on the light jet.

Just one more tidbit that I thought was interesting. That Daniel Simon guy? He also did the livery design for this:

Daniel Simon - Edge.jpeg

DamoRC
 
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DamoRC

Well-known member
Mentor
#2
Design

Source Material

I described in the introduction how Daniel Simon's images were excellent starting points for the design of the plane. But three-views they ain't. In fact there are no good three views available that I could find. So I decided to use some of Daniel's original artwork and screen captures from the movie to establish the profile, plan, and front views that I would need.

I can use this profile picture from Daniel Simon - not 100% straight on profile but I can make it work.


Then I took to Youtube to grab some screen captures from videos of the Light Jet scene.

This one will work for a plan view...

another screen cap.jpg

...and this one will work for a head on view

screen cap 7.jpg

Of course, those of you who have seen my earlier posts know that I already had started on a Sketchup model of this, so I already know these pics will work (-ish). But the images are not perfect and there are some inconsistencies between some of the concept art drawn for the model and how the model actually appeared in the film.

Initial Drawings

Plan View Drawing
So this is the plan view drawn in Sketchup using the screen capture image. The wing, v-tail, and pylon are drawn as simply as possible. Only one half of the plan view is needed. The pic shows the panel in solid form (top) and using the "x-ray" view (bottom) so you can see the original plane in the background. Ignore the dimensions shown for now. These were added so that I will be able to scale the various views (plan, profile, front) with each other, a step you would not normally have to do if using a regular three view.

Design - Plan view initial drawing.jpg

Front View Drawing
The front view was mostly used to establish some basics around angles for the v-tail and wing. Although the picture is not 100% from-the-front, it will work and I can make modifications later as the design progresses. So I have ~25 degrees (from Horizontal) for each of the v-tails (making the v-tail angle 130 degrees, which is probably a little on the large side from what I have read about v-tails). But it's a good starting point. Also figured about ~6 or 7 degrees down angle on the root section of the wing. I am assuming the remaining wing is level. Lastly, I can use this view to establish a shape for the "grill". Again, solid and x-ray views are presented in the pic.

Design - Front View Initial Drawings.jpg

Profile View Drawing
The initial profile drawings mostly help capture the shape of the "fuselage" for want of a better term. It also provides a second look at the v-tail and pylon setup which will help establish the positions of these parts in the final model.

Design - Profile View Initial Drawings.jpg

Wings and V-tail modeling.

Next up was to take the wing and v-tail panels from the plan view and set the angles in 3D space. To to this requires making a new panel that can be rotated to the desired angles and then transform the points from the original flat piece onto this surface.

Angles for Wing.gif

The same approach was used on the v-tail section. A symmetrical airfoil model was added to both mostly to improve the looks of the model in SU. That being said, I am very impressed with the construction and performance of the FT Edge airfoil so using this as a template is a possibility.

Added Airfoil.gif

These airfoil objects are grouped with the original flat panels in Sketchup so I can view or hide either part depending on what I am trying to model.

Next up was to map these pieces onto the plan view again to that their spatial position in the model can be established. When the original flat panels were drawn I kept the center line of the pylon in the panel so following the adjustment of the angles the parts could be aligned exactly with the pylon and be in the correct position. Here is the plan view with the parts added back and you can see how they now fit in 3D space.

Wing and V-tail set in 3D positions.gif

With a simple cylinder model of the pylon made, and the wing an v-tail aligned, the mirror image can be copied into the model to get a feel for how she is going to look.

first look at 3D.gif

Although this looks okay, I am a little concerned at this point that the V-tail is too flat. So I made another one at +10 degrees (bottom panel in the next pic). This would reduce the v-tail angle from 130 degrees to 110, which is more typical but to keep the same planform its a lot longer. I needn't lock into one or the other yet, changing later in Sketchup should be pretty easy.

Compare 25 versus 35 v-tail.jpg

Fuselage

Back to the profile view, this time tracing out the fuselage. I left the pylon center line in place to help with alignment with the 3D model.

Profile view Fuse Design.jpg

At this stage its okay to use all manner of curvy bits to get the shape right but ultimately, to convert this to foamboard, some of the curves will need to be "averaged out" to straight sections.

Cues to the 3D shape can be taken from a couple of images. A screen capture of the jet being formed in the movie shows that the basic shape is composed of oblong/circular/elliptical type rings and they are all pretty much the same shape (which makes things easier).

Light Jet Structure.jpg

From one of the images of the rear of the craft you can get an approximate view of the shape. So a simple circle shape was added, then the width was reduced and finally a slight further narrowing of the lower portion of the ring was completed. This will be the cross sectional former to model the fuse in Sketchup. Hard to tell if this is a really accurate representation of the whole fuselage cross section but I think this will do the trick.

Creating virtual former shape.jpg

Next is to "cut" the profile view of the fuse into manageable sections. Given that I am going to use the score cut / gorilla glue / fold / frame approach, I need to average out some of the curves with straight lines keeping in mind that I would like to keep the fuse to four, maybe five sections.

Fuse sections outlined.jpg
Okay - that ended up being 6 sections.

Now this profile and the cross sectional profile are combined to build out the 3D fuse. The former is copied to each section of the profile keeping the centers aligned (1) . Then it is re-sized so that the top of the former meets the profile and the center of the former stays on the center line (2). The former is then resized again, this time pulling only on the bottom of the former so that it aligns with the bottom of the profile (3). Finally, the formers are planked in-silico (4).

Fuse Formers and Planking.jpg

This planking piece is a little tedious. Although Sketchup has an extrusion type of tool (called Push/Pull) I find that the slower "join-the-points-by-hand" method gives me better control over how the part turns out.

Planking in SU.gif

With one half planked, its mirror image can be made so that the whole fuse piece is now modeled. Using the pylon lines as a guide, this piece can now be inserted into the wing/v-tail/pylon part of the model. Lookin' purdy good at this point.

Wings and Fuse Together.gif

To finish the fuse the front needs to be sculpted. The part highlighted in the following image is what needs to be removed from the front of the fuse.

Profile Cut Out.jpg

This portion is copied, cleaned up, and extruded into a 3D shape that can be subtracted from the fuse.

3D fuse cut piece.jpg

Here are the two pieces joined....

fuse and extruded piece together.jpg

Then the faces of the two pieces are intersected and the intersection line produced is used to remove material from the front of the fuse.

Fuse cut out complete.jpg

Basic Modeling Done.jpg

Next up is the light engine intake. Taking the shape from the head on screen capture, a 3D element was drawn in the same way described for the fuse. Then it was inserted into the existing model and scaled to fit.

Light Engine Intake.jpg

This pretty much covers all of the main elements for the design and there is more than enough detail here to build a chuck glider. Next up on the design front will be adding details to the existing parts and thinking about what the internal structure is going to look like. But first....

Scale Issues
One of the challenges for the build is to be able to balance the plane appropropriately. Online CG calculators put the balance point roughly where the two tapered leading edges intersect (ignore the actual lengths here, this is before the model was scaled appropriately).

cg calc by ecalc.jpg

The plan was to use batteries placed in the pylons to help achieve this balance. This means that the pylons need to be large enough in diameter to hold the battery. If I go 4S EDF approach, then the pylon will need to be ~2.8 inches in diameter to hold the 4S 2200mAh batteries that I have on hand. I can get away with smaller pylons if I drop the EDF and use a prop instead but this would have to be a "ducted prop" placed far forward in the fuse to avoid additional balance problems. So if I scale the current model down to have a 2.8 inch pylon diameter, how big will it be? Well, the wingspan would be 116 inches! That's almost 10 feet - way bigger than I intend to build the model. I was hoping to build at the 40 to 50 inch wingspan scale.

Okay - plan B was to add extensions to the pylons that were larger in diameter to hold the batteries in the hope that this would not destroy the look of the plane. I put together two of these, a cylindrical one and a rectangular one which looks like some of the concept pictures. So how does a 40 inch wingspan version look with these extensions? Pretty bad.

Pylon extensions on 40 inch.jpg

And it gets worse, because at this point I recognized that the fuse seemed narrow compared to the batteries - so would a 70mm EDF fit in there? Nope!

70mm EDF in 40 inch WS Light Jet.jpg

Eventually, after a number of rounds of scaling and squeezing components in, I figure that a 72 inch wingspan is doable, not so huge that it won't fit in my car (I think) and just about big enough to get everything in. But I will need to ponder this some more.

A little later....

Okay - I think I will go with the 72-ish inch version (I might trim a little off the wings and widen the fuse slightly). Rather than take my fat rump out to the Prius to confirm it would fit, I drew up a quick model of the Prius and checked the fit that way.

Plane in Prius.jpg
(nope - I didn't draw this, I downloaded it from the Sketchup 3D Warehouse).

After a little bit more tweaking and resizing I think I finally got everything to fit. The fuse was scaled 5% larger and I reduced the angle of the v-tail so that the EDF could fit. From the pic you can see that the thrust tube for the EDF still interferes a little with the rear of the fuse but I think this will be okay. The battery pods don't look too bad at this scale and I think I will ultimately go with the rectangular prism Scaling Done.jpg version because they have a little more room.

Rider
I would like to do something a little more "3D" for the rider on this model, but it will still be pretty simplistic as a fully 3D rider will hamper the EDF inlet. Tried to draw a profile based on the pics I have and then positioned this flat rider in the center of the model.

Initial Rider Added.jpg

Added some depth to the torso and angled the limbs....

rider 3d ish.jpg

... and it fits reasonably well in the craft.

rider in position.jpg

Not going to spend any more time on this for now but I am going to have to fix the head so it looks less like a Star Wars battle droid.

TBC...
 
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PsyBorg

Fly Angry
Mentor
#10
How did I overlook this one. Will be following this for sure. Great start Damo.

Wonder how many total pieces will be in the build with all them angles and things sticking out everywhere. See if it beats the Edge 540 build