Help Regarding 3d modelling for spaceplane design study paper

[CommanderSpock]

Hi folks, it's been a while since I've been on. 

For a little background, I'm a senior in high school. I've been in a program for three years now called Science Research, where students are given the opportunity to conduct original research, culminating in the writing of a research paper, as well as a variety of science fairs. For my project, I've been working on a design study for a single stage to orbit spaceplane (big surprise) that uses three modes of propulsion to get into orbit and back onto the ground. Here's an excerpt of my paper, to give a description of the craft itself:

"The concept of this spaceplane is a hybrid three mode aircraft based on the design of the SR-71 aircraft. The aircraft is already optimized aerodynamically and structurally for high mach flights, and are proven designs. While it’s the basis for the design, the only visual commonality between the spy plane and spaceplane will be the bird’s-eye profile. From the side view of the SR-71, the design of the spaceplane will be different both above and below the chine of the fuselage. Below the chine, the fuselage will be squared, and covered with heat protective tiles. This has three purposes: one, to simplify the process of applying the tiles; two, to create a lifting body effect on the fuselage; and three, to increase the area inside of the fuselage for fuel. The wings will be lowered and thickened slightly, in order to meet the bottom of the fuselage, and provide more area for fuel. Additionally, the lift from the body will allow the wings to be shortened width-wise, creating a slimmer profile for more efficient high-mach flight. On the wings, housed in the nacelles of the Pratt & Whitney J28 engines used on the SR-71 will be pre-cooled turbojet engines, build to take the spacecraft from the ground to mach 6 and 20,000 meters. Halfway down the bottom of the spacecraft will be the intake for the scramjet, which will take the spacecraft from mach 6 to mach 17, and 70,000 meters. The scramjet will exhaust from the bottom rear of the spacecraft, with the engine also covered in protective tiles.    

Above the chine, the body of the spacecraft will be radically changed. The cockpit will be removed, along with the rest of the upper body of the Blackbird. In its place will be a large conformal tank, with a fuel and  an oxidizer tank within. Between these two tanks will be a small cargo bay, with a 5,000 kg capacity. At the end of the conformal tank will be two Aerojet Rocketdyne AJ10 engines, proven as reliable vacuum engines over the past 60 years. (May be switched to one Merlin 1D vacuum engine)"

I have the technology and math covered- what I need to do now is create a printable 3d model of it, both solid and cutaway. The images of the craft in KSP included are what amount to a rough sketch for me, as I have no skills in actual sketching on paper. 

https://imgur.com/a/4e7uexY    (I don't remember how to embed albums, oh well).

I'd really appreciate it if y'all could help me create models of this craft, as it would both aid my presentations at fairs, and provide a really nice final product for all the work I put into my research over the past three years.

 

Thanks!

[Mad Rocket Scientist]

You have two options:

The first is solidworks or another engineering 3d modelling program. These are typically called "solid modelling" programs. Solidworks is reasonable easy to learn for simple shapes, as long as you are OK with approximations rather than precise shapes. Unfortunately, it and other professional CAD programs cost so much that the only reasonable way to use it is if your school has purchased it already. However there are some free options, search for "solid modelling" or "CAD software." Some of these are what is known as "parametric" which means that you can change one part and have everything after changed to match, which is really convenient.

The second is more art or visual design oriented 3d modelling programs. These are called "surface modelling." The workflow is quite a bit different, and more focused on ease of making complex shapes than precision and mathematical definition. Blender is pretty much the best option, and it is entirely free. However, compared to solidworks, blender has a much steeper learning curve, but many more tutorials online.

If you want to do any kind of analysis of the model (even just center of gravity calculations) CAD software is a much better option.

You could also consider just carving and sanding wood, like old wind tunnel models.

[CommanderSpock]

On 12/1/2018 at 12:46 AM, Mad Rocket Scientist said:

You have two options:

The first is solidworks or another engineering 3d modelling program. These are typically called "solid modelling" programs. Solidworks is reasonable easy to learn for simple shapes, as long as you are OK with approximations rather than precise shapes. Unfortunately, it and other professional CAD programs cost so much that the only reasonable way to use it is if your school has purchased it already. However there are some free options, search for "solid modelling" or "CAD software." Some of these are what is known as "parametric" which means that you can change one part and have everything after changed to match, which is really convenient.

The second is more art or visual design oriented 3d modelling programs. These are called "surface modelling." The workflow is quite a bit different, and more focused on ease of making complex shapes than precision and mathematical definition. Blender is pretty much the best option, and it is entirely free. However, compared to solidworks, blender has a much steeper learning curve, but many more tutorials online.

If you want to do any kind of analysis of the model (even just center of gravity calculations) CAD software is a much better option.

You could also consider just carving and sanding wood, like old wind tunnel models.

Thanks! I'll look into the software you recommended!

[pincushionman]

Many CAD programs are available for free or at a reduced price for students. Since I have not been a student myself for some fifteen years, I haven’t been looking for such deals or how to prove you are a student. Other than Autodesk Fusion 360, which is free for hobbyists, startups, and students (I only know because I just downloaded it myself to tool around with).

But consider what you’re trying to accomplish too - a CAD program may be the wrong tool for making concept art and models. You’re certainly not going to be getting into the technical detail level where those kinds of programs really show their strengths. A simpler CAD system like SketchUp might be more appropriate, or even eschewing CAD altogether in favor of 3D modeling programs like 3DS Max (also Autodesk, also free for students) or Blender (FOSS). Hell, Wings3D might be a good place to start, given that you’re going to be modelling essentially a static object. It’s pretty approachable.

Edited December 5, 2018 by pincushionman

[Mad Rocket Scientist]

1 hour ago, pincushionman said:

Many CAD programs are available for free or at a reduced price for students. Since I have not been a student myself for some fifteen years, I haven’t been looking for such deals or how to prove you are a student. Other than Autodesk Fusion 360, which is free for hobbyists, startups, and students (I only know because I just downloaded it myself to tool around with).

Often a .edu email address and entering the name of the school is all that's required.

1 hour ago, pincushionman said:

But consider what you’re trying to accomplish too - a CAD program may be the wrong tool for making concept art and models. You’re certainly not going to be getting into the technical detail level where those kinds of programs really show their strengths. A simpler CAD system like SketchUp might be more appropriate, or even eschewing CAD altogether in favor of 3D modeling programs like 3DS Max (also Autodesk, also free for students) or Blender (FOSS). Hell, Wings3D might be a good place to start, given that you’re going to be modelling essentially a static object. It’s pretty approachable.

There's also freecad: https://www.freecadweb.org/ No idea how good it is, but it appears to completely free and open source, no trial versions.

Wings3D is good idea, I can recommend it for beginners. It's much less intimidating than blender, but it's also less powerful and slower. It's good for getting started though, since blender has something of an obsession with doing everything. 3D modelling? Of course. Material editing? Check. Raster image editing? That too. Particle simulation? Naturally. Soft and hard body physics simulation? Yep. Rendering? Yes. Non-linear video (and audio) editing? Animation and rigging? Chromakey? Motion tracking? UV editing? Compositing? Inverse kinematics? All of that. It even has a built in game engine, although that it slated to be removed.

All of that can make the hardest part of using blender just sorting out the menus you actually need from the ones used for everything else.