SULSA: Why Draw When You Can Build?

SULSA: Why Draw When You Can Build?

A little while ago I posted about drawings.  You may have noticed that although I can extol their virtues, I’m not one of life’s great drawing enthusiasts. The less I have to force myself to sit down and work on them the better. Actively put, I seek drawing avoidance.

One way to avoid having to deal with drawings excessively is, of course, to design less stuff. A good way of doing that is to cut down on the number of components you have to design in the first place. In order to achieve that, you’ll probably need new design and production methods. Enter additive manufacturing, stage left.

3D printers have started their seemingly unstoppable march towards the mainstream. Whilst true mass production with additive manufacturing remains a long way off, it is starting to enter the consciousness of businessmen as well as engineers (The Economist has carried articles on them like this of late). Proofs of concept are becoming ever more intricate; bikes, bones and art have been created using 3D printing. And now, a group from Southampton University has created the first aircraft fabricated using 3D printing techniques, dubbed SULSA.

The design, though bang up to date with its twin “tailerons”at the back, is conceptually based on two notable military aircraft of WWII, namely the Supermarine Spitfire which provided SULSA with its elliptical wing planform and the geodesic fuselage structure from the Vickers Wellington. The designers of those aircraft strove for optimum solutions to particular problems. They made functional decisions based on optimum aerodynamics (Spitfire) or structural strength / weight and robustness (Wellington), to the noticeable detriment of manufacturability. The elliptical wing had so many unique shapes in it, including compound curves, that it was a nightmare to manufacture (no wonder the RAF bolstered its numbers with North American Mustangs, whose wings were straight, true and manufacturable). Equally, whilst the Wellington’s geodesic structure appears relatively simple, each and every bar and strut in that structure was unique and so required a drawing and a part number.

The whole of SULSA, by contrast, is made up of four key components, “plus the avionics” (I’m sure our electronics friends will excuse the rather dismissive phrase from the video, treating the whole digital control and autopilot system like nothing more significant than a rivet). These are clipped together, thereby eliminating a vast number of fasteners (hallelujah!), and the plane is good to go.

Naturally, there are caveats in singing the praises of SULSA and their like; they’re prototypes, after all, and nobody’s going flying in a printed airplane soon. But if like me you would rather be doing something other than making drawings, spend some energy making stuff;  you’ll hardly remember you were told to draw something up when you’re already holding it in your hands.

Thanks to Chris P for the RC plane picture (not a SULSA)