With this, I present the end result of another completely unproductive day:
Paper-chuckranoplan grew! It was a carefully tuned process of feeding and watering, as well as exposure to the proper amount of cosmic radiation.
Or carving foamcore. Whichever one you think would work.
Paper-chuckranoplan 0002 (the last effort, while nicknamed 0004-FML, has now been given its official designation) is about 1.25 meters long (45″) and has a .6 meter (24″) wingspan. The tail span is 18″. This took about 7 sheets of foamcore and like two whole hot glue sticks to finish.
A view from the front. I built this frame double-walled since a single-wall one would just look silly at this scale. In this picture, I’ve also added the roll control winglets, which are 7″ span (each) and 4.5″ long at the root.
Being double-walled and large, I might actually commit some of my recently purchased modeling components to it. In other words, it might get flight electronics. I actually ended up using two 3S/1.3Ah packs as nose ballast (in lieu of finding a large enough nut).
So how well did it do?
Like awesome. Walker Memorial’s first floor is about 100 feet along the diagonal where I did most of the flights. I estimate PC0002 was able to glide about 80% of that if I gave it a good shove. I’d say that’s legit, and totally waiting for a set of ducted fans. I was constantly shifting the CG aroud during the tests, which is why some of the flights look a little shaky. The CG really is crucial in these things – too far back and it never picks the tail off the ground (or just straight pitches up and then falls over), and too far forward and it just drags the nose the whole thing.
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.