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3D/CAD Overview

My tutorial DVD's, for those interested in using 3D to design aircraft, are on the Products page. My 3D Model Catalog is located on http://www.mikejamesmedia.com In addition to 3D models, there are some free 3D RC parts you can download.

You'll find many more advanced articles, with much more detail, on mikejamesmedia.com. This is merely an introduction to using 3D as a design tool for those who haven't done it before. So if you're new to 3D, maybe this will help explain some of the "why" and "how", to get you started.

Why use 3D at all?

Incredible models can be built without a computer. Having said that, here are some of the additional benefits you can gain from 3D modeling:

• Precision: Modern 2D and 3D tools give us all the ability to produce very precise parts, and easily alter them, whether it's their raw dimensions, or simply scaling them up and down. Certainly faster than redrawing a traditional set of paper plans, and much more "durable", since computer-created plans don't yellow with age, or even get wrinkled.
• Accuracy: Notice that I put "accuracy" on a different line than "precision"...
  "Accuracy", in this case, means the ability to create your 3D model faithfully, according to some outside reference, whether it's an original design or a scale reproduction. Most modern 3D software will allow you to import 2D drawings, which you can use as a backdrop, to accurately "trace" over. This at least gets the 2D outlines right, even if you don't have 3D cross-sections to import, and have to guess about some of those. (More on "extrapolation" in the more advanced articles on mikejamesmedia.com)
• If you have an interest in manufacturing, it's possible to create a "machine-ready" moel in 3D, and do quite a bit of testing, before spending any testing or manufacturing money. Since the files are digital, it becomes easier to share updates with other designers, via the internet.
• Visualization... Often, designers can simply look at something and intuitively know that it's "right" or "wrong". A 3D model will cost you some time at the beginning, but will save you time later.
• You can create nice 3D images, for your own entertainment, or for the purpose of advertising models that haven't been built yet. Modern advertising agencies love 3D models, when they're done right, because they have more control over every aspect of the viewing angle, colors, lighting, etc.. You might be surprised at how many magazine product layouts are entirely digital, and it's getting harder to distinguish these images from photos.
• You can test the fit and (motion) operation of internal equipment, as well as scale details, before constructing a prototype. Since one thing leads to another, it will also help you find interference issues, predict weight and structural issues, and can even help plan manufacturing methods.
• If you develop a separate interest in 3D during this process, you can use your 3D models in a variety of ways, outside of RC. They can be sold to others who don't want to take the time to build one, they can be used in various imaging projects and animations, and, depending on how you make them, they might also be suitable for use in either video games or motion pictures.
• With the highest-end 3D software, such as SolidWorks or Catia, you can even do realistic engineering analytics on the model... airflow, stress, etc..

How to get started... Selecting software and modeling methods, etc.

The answer to "What software should I buy?" is that "It depends on what you want as an end product." This is so important to know before you buy, if possible, because the price of the software can vary greatly, and the methods to create the models can vary greatly, as well. Here are a few examples...

If you want to be able to take your files direct to machining, then you must buy one of the programs that supports those file formats. Here are the Google results for a search on "3d file types for manufacturing". These are typically more expensive, and typically use a modeling method called "NURBS", which is an entirely-different approach than most (polygonal) 3D modeling software produces. That's because today, there's a huge market for 3D modeling, outside of manufacturing. Expect to pay over $1000 for this kind of software, and as much as $5000 to $16,000 if you want SolidWorks or Catia.

On the other hand, if you want to produce images, animation, and (given some workarounds) "plans" of a sort, then typical 3D modeling packages will server you well, while saving you thousands of dollars. I used Carrara Studio for many years, and now use "modo", by Luxology.

Simply put, "Buy the best 3D tools you can afford." Trying to play it cheap (or free) usually only means that the quality of your work will suffer in one way or another. For example, be sure that the software you buy will output the file types you need, and not some non-standard, proprietary type. One of the best alternatives is the fantastic open-source 3D software, "Blender", which you can download free, at http://www.blender.org.It runs on Windows, Mac OS X, Linux, Solaris, and Irix.

Like all other computer applications, 3D apps have become more intuitive over the years, and you don't have to be a rocket scientist to figure them out. Still, if you're new to computer drafting and/or modeling tools, whether they're 2D or 3D, there is a stiff learning curve, simply because there are many approaches to building the software, and a lot of tools and methods to learn. The good news though, is that once you've learned to use any of the typical tools, you'll have a much easier time transitioning to the next one. Just force yourself to get over that hurdle, and you'll have some great new skills.

Don't be surprised if your computer needs some "help", when you get into 3D. Often you'll find that you'll need some more RAM, for example.

Managing Complex Projects

An example:

The largest, most complex project can be broken down into manageable pieces, with a little planning. So don't let the sight of something complex spook you. Just start, and keep going. Here's a general outline of the process I've used many times. You can start with minimal documentation, if need be, and refine the model as you go. In this case, it's the construction of my Piaggio "Avanti" P180 model, which I first created in 1998.

I began this 3D model with only a small 3-view from "Jane's", which gave me just enough information to create some "starter" parts. Although not scale, it immediately started to give me ideas on how to proceed, and how to break up the model into sections, like "fuselage", "vertical fin", "Wing Inboard", and so on.

Use your software's lighting and reflection to your advantage.... In the absence of hard data, use photos of the actual aircraft as a reference, and then adjust the lighting of your 3D scene to match. You can see if the reflections look the same, pointing out curve errors. It works!

Wireframe views can be confusing to look at, but will sometimes show you future issues. They will also help you fix technical errors in your mesh.

If I don't have hard data for the interior, I'll wait until the exterior shape is "frozen", and then start adding it. If youre exterior shape is correct, it will help confine your interior parts, which at least gets it somewhere close.

By the time you get this far with your model, you'll know the actual aircraft very well, and your eyes will help you find the few remaining errors quickly. Doing some semi-realistic renders like this one, and comparing them to photos of the actual aircraft, will help a lot.

Don't forget 2D. Often, it's helpful to make some 2D drawings, before building a 3D part. It will help with the planning process, and point out issues you'll have to deal with.

Go "window shopping"!

You now have a general idea of the process. I suggest searching all the major 3D software manufacturers you can find on the internet, and keeping some notes. It will help you narrow your 3D choices. If you'd like to read some more advanced articles on the processes I use, visit http://www.mikejamesmedia.com