Right, it's a design challenge! Criteria: "The ultimate slow flyer". That's all, right?
Nope.
Josh makes a reference to the fact that the plane needs to be a great glider, too. So now we need a great glider that is also an amazing slow flyer. This complicates things slightly. Make a glider, easy. Make a slow flyer, easy. Make them as one plane... Not so easy. Most of the gliders I have made are quite nimble. And the slow flyers, not so great on the gliding side of things...
Let's quickly pause for some reference here:
As a kid growing up in South Africa, RC planes weren't ever an option. But fortunately, paper had been invented and my twin and I had been gifted a paper-folding (mostly airplanes) book. One of the gliders in it was a favourite, if made correct, we swear we could have one fly for minutes in thermals. It was most likely more to the tune of a 15-second flight, but having that happen as a 7-year old watching your plane drift away on a warm breeze was exhilarating.
Fast forward 30-odd years, and a move to Canada has handed me the luck of being introduced to Flite Test and the world of RC planes. I love the EZ-system for the ease of use and ability to have a quick fly around the local park. On a calm evening, I'm more likely to grab an EZ plane than the Tiny Trainer or Mini Scout that are hanging about.
Back to the present:
For my design, I wanted to embrace the Red Bull Flugtag feeling to the maximum and create an EZ plane that if tossed (somewhat gently) from an elevated platform, will glide gracefully and far from the point of origin. Then as it's about to land in the water (or in my case, grass), apply some power and have the plane transition to an elegant slow flying bird.
The result: May I present to you, The EZ-Skilpad.
From that childhood spending hours throwing well-folded paper around, I recreated what I remember the glider to be. I don’t have the book anymore and neither does my twin, so a sketchy memory is all I was to draw from.
Test versions of the Paper Plane.
Paper Skilpad Glider Attempt #20
After about 20 attempts, I had a design that I was happy with. I then realised that I am a grown adult with the internet and an Amazon account, so I soon found the book, "The World's Greatest Paper Airplane and Toy Book, by Keith R. Laux" and ordered it.
The plane in question is called the 'Flat Flyer' and I have subsequently made my own templated version of the plane. It differs from Keith's mostly with the cut-out wing shape. His was a lot squarer, where I favoured a more sloped trailing edge on the main wing.
Made out of Vellum Paper, the plane keeps it shape nicely.
The Flat Flyer paper plane has a great glide slope and if made and thrown correctly, on a windless day, it should consistently give you flights between 6-10 seconds. Not ground-breaking by any stretch of the imagination, but if it catches a hint of a thermal, you'll end up chasing it for a while. The weird shape of the wings (dihedral front and anhedral back) makes it an interesting plane to look at and throw about. This is not how it's in the original design, but I've found it gets more stable flights in this configuration. The Flat Flyer is designed to be made with a light tissue paper, but regular office paper works fine. Now beware, this is a delicate plane, handle it with care!
Anyway, onto the foamboard version.
The design roughly mimics the paper version, except with a fuselage that extends out the front to carry the electronics and balance out the plane, as I have forgone airfoils. Those have been attempted (normal FT style, Mini-Scout style and KF airfoil), but the simplicity of a flat piece of foamboard with a bevelled edge seems to do the trick.
Prototype Version 3-1 ready for testing
Prototype Version 5.2, successful enough to get decorated.
The final version of the EZ-Skilpad has a smaller main wing, with a greater rounded slope on the trailing edge and the plane has been shortened somewhat between the main wing and tail section.
The Final Designs
All-up weight with the electronics and 350mAh battery comes in at a feathery 38 grams. The plane glides nice and gently to the ground with a gentle to moderate throw and has a slight high-alpha flying style when power is added.
I've added both the paper plane and EZ-Skilpad into a Resource with a build-log included. My final version has all the paper stripped off and uses the v1 powerpack. Future tests with the v2 and all the paper kept on will be undertaken.
This has been a fun project! Hope you enjoyed reading along, and if you're keen to have a go with this design, I hope you have a blast with it!
Carl (not so secretly known as 'AgentC')
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