I officially renounce any claim I might ever have possessed to being an engineer.
I just straight give up. There’s no point in continuing.
…because look at this thing!! Isn’t it SOO CUUUTE? And adorable and foamcore-y and completely undesigned and unplanned and made in 20 minutes while I was supposed to be tutoring 2.007?
And it works exactly like it should. Of course it does… I didn’t think about it too hard beforehand.
Anyways, meet Chuckranoplan 0004FML, where the FML is for for “foamcore, medium length”, I swear. 0004FML is about 30″ long and made from 5.5-6mm foamcore, the kind you put bad science fair posters on. With the Nut of CoG Shifting, it weighs a bit under one pound. The wingspan is roughly 18″ (just one entire foamcore sheet), and the little winglets take it to about 30″ wide.
Here’s the planform overall. This was certainly the quickest build I’ve ever pulled off. There was a little bit of precognition here, since Shane and I have been meaning to just pick up a pile of foamcore and go for it, since there’s a large supply for the 2.007 class. The joinery was with pretty standard hot glue, and there’s no other materials used in construction, excluding the nut of course.
Here’s a front lower view showing the air pocket space under the wing and the orientation of the tail.
While it did work somewhat at first, only after adding the dihedral winglets did it actually achieve meaningful roll and lateral stability. So it seems that these little winglets do play a pretty significant role in the dynamics of the vehicle after all. And it does make sense – the winglets contribute to the stabilizing dihedral effect while the main wings provide most of the lift. The technique is known already to GEV designers and is called a “composite” wing.
0004FML will not get any flight electronics, but it was a good geometry study for 0004 proper. And it looks like I’ll definitely be considering those winglets more seriously.
Here’s some shove testing video!
Doesn’t that work so awesome!?