The revolution in digital technology is well-documented, less know to the normal participant in society is what that revolution means for the wannabe-engineer.

How many times do you get an idea in your head and think, "why doesn’t anyone make that?"

50 years ago making anything besides a birdhouse was a monumental task.  Imagine all the engineering that went into the Ford Model-T or the Nazi V1 and V2 rocket systems.  Back before three-dimensional visualization car engineers had to keep a beer fridge in the office to be able to put those complicated car body designs into production with the nervous breakdown associated with piecing complicated three-dimensional part together in their heads.  There are three basic groups of technology that allow the current home-engineering to design and build a number of things under the sun.

Computer Aided Design (CAD), essentially the ability to draw and test your creations on the computer screen.  So if you want to know how strong the wing of your aircraft needs to be, you make the design in the computer, apply forces to it, and the computer tells you if it will break or not.  Countless millions of dollars are saved using software like ANSYS instead of hand-calculations and building prototypes for crash testing.  For some basic 3D CAD check out Google SketchUp.

Computational Fluid Dynamics (CFD), modeling required to visualize fluid flow patterns around structures.  How aerodynamic is your car body?  What’s the lift coefficient of that new aircraft you’re designing?  What will that new custom body do to the acceleration of your custom hot-rod?  A list of free CFD packages is available at CFD_Codes.  For some aerodynamic lift calculations of an airfoil you can do some really cool analysis stuff with Airfoil-Analysis from RLM software.

On Demand Manufacturing (ODM).  It used to be, you’d need access to a full service machine shop with full-time technicians to help build your prototype.  This meant that the cost of launching a new product was impossible to attain for a normal person.  Now you can take your design for that 4×5 camera body or custom break-plate, send it to a custom CNC company like eMachineShop.  One their website you can design your part and pick the materials you need…and a few weeks later the aluminum milled creation is sitting on your doorstep.

Professional analysis programs like ANSYS can be a tad costly for the private home user.  The cost of ANSYS outside of the university student license umbrella is about as much as a nice car.  But like all computer-based technologies, what was breaking-edge five or ten years ago is now open-source enabled.  The number of free or low-cost shareware engineering programs available is truly impressive –  and means that even home computer users can setup a computer design and engineering environment to turn a little tinkering idea into a custom full-functioning prototype.

Coming up later: Design Your Own Plane and Composite Manufacturing