Hey Chuck,

any time. Sharing is one of the reasons we're all here for. Besides, the credit has to go to RD who did the initial work on this. The plan is evolving as something is brewing on the Aurora front - if it works out, you' might be quite pleased as will I. But it's early to tell yet.

Greg,

I didn't realize this sort of thing was that exciting. But I have to agree, a thread on the "digitizing" process of a vintage classic would be a great idea. But let me say this. You work professionally with Photoshop I gather. PS is great with anything that has to do with dealing with raster based files (bitmaps). Illustrator is it's meaner but smarter twin. Most people don't use or like Illustrator. I find it quite powerful. For a non CAD wizard, I'm actually able to produce a fair amount of stuff with it.

Take one of RD creations once again - his 66% UFO CAD plan. Using AutoCAD he transferred the essence of the design by tracing the key elements of the model - the important lines necessary to produce a scaled model and eventually a laser cut kit. I've decided to build a 77% UFO for 25-32 piped power. Simply with Illustrator I'm actually able to alter and modify just about any curve, line or object of his 66% version. It's no where as sophisticated as CAD since it has no 3D capabilities and it is also fairly rudimentary in it's workflow but in pinch it get's a 2D plan done. It also has no provision for dealing with or creating airfoils other than those you might draw freehand.

Below is a single snap of how the 77% plan is evolving. The plan now contains several elements (some are not shown - e.g., radio, landing gear, tank, engine and pipe) and is fully vectorized and layered which means we can build a 30% or a 200% UFO just by scaling the plan. There are of course elements to consider such as how wing area and wing loading vary as we scale the plan linearly. This is why a 2m F3A model has comparatively small wings for it's size. A 25 size model on the other hand, requires a larger wing for the size of it's fuse in order to perform well. Otherwise, means to reduce weight have to be found. As the model is reduced in size, we also find that we need to alter the aspect ratio of the fuse (height and width and sometimes length) in order to provide adequate room for components. This of course also alters the flight characteristics of the model but that's half the fun of scaling designs.

The photo below also shows how one can cross-check the work done on formers with respect to side and top views of the fuse. This insures accurate dimensioning (tricky to get right in Illustrator - easier in true CAD). 3D CAD is more sophisticated with this as it can actually extrude the framework and verify the parts fit in 3D space.

Regardless, the process really boils down to a set of lines, curves and guides. The rest is just mouse work!

David.