OpenVSP

I put away my 3D drawing projects for some time because of a combination of frustration with the complexity of the tools and the nagging thought that they were taking too much time away from my photography.  Recently, I have been seduced into the 3D world again by the appearance of a new tool, OpenVSP.   As the NASA web site says:

OpenVSP is a parametric aircraft geometry tool. OpenVSP allows the user to create a 3D model of an aircraft defined by common engineering parameters. 

Compared to anything else I've tried, OpenVSP is blazingly fast, and * taa-daa * it's free.

Here is an example design that comes with the program showing its capabilities:

Here are  several doodles I produced in a few minutes each:

Here's my x-plane that I've been using to familiarize myself with the program's drawing tools:

There is a very good manual for OpenVSP which includes instructions on all the basics and a few ok video tutorials.  To get beyond the basics takes some dedication; I'm trying to figure out at the moment how to construct a typical aircraft coss-section which inludes a canopy.  Hopefully, there will be some online discussion developing around the program which will help to answer questions.  Since NASA has released the program as Open Source, perhaps there will also be some development of additional features and import/export options.

around and around

I'm working on a new SketchUp model of a WWI plane. The 110 hp engine in it was an Oberursel Ur.II, a German product copied from a French design. I was vaguely aware that in such rotary engines, much of the machinery went around along with the prop. It wasn't until I began looking at CAD representations that I began to understand why the rotary was considered a good idea at the time, or what made them work. Two CAD depictions in particular make the functioning of rotary engines a lot easier to understand.

The cut-away depiction below is from the marvelous Vintage Aviator site. If you look closely you will see the key feature of the engine, which is that there are two axes of rotation.



How the machinery is linked by the two axes is illustrated with great simplicity by an illustration at the Animated Engines site. Once there, click on the "Gnome Rotary" link to view the animation. Under the "About" link, you will also find an excellent explanation of how the engine animations are produced.