When I saw this video from rctestflight I knew I will build something like that for myself. A voila, few months later it is done. Here is Dropship Glider.
It is 29cm long with 20cm wingspan. Weights 97g AUW and has 21g/dm^2 wing loading. So, in theory, should glide. Somehow… If I got center of gravity right. And did not made ailerons too big. Or…
Delta 6mm Depron "wing" is attached to 6mm carbon fiber rod and has some quite big dihedral: 15 degrees.
The biggest problem was radio link and mixer for ailerons. I could not use my Taranis: I need that for a carrier and only radio control link I had was EM-16 with PPM output only and no way to setup any kind of mixer. The radio just has no "features" like that…
So, took one Arduino Pro Mini and wrote short program that acts as PPM decoder and mixer for ailerons.
power is supplied by 1S LiPo taken from my Tiny Whoop
FPV AIO Eachine TX02 also taken from my Tine Whoop
5V is supplied from cheap, regulated, step-up converter
3rd servo is to release tether
First flight, or rather drop, tomorrow. There will be a video from the event of course…
Next week passed and Depron Airboat is almost ready. Almost, since it still needs some finishing and I'm missing a BEC. Turned out that total power usage of one 9g servo and FrSky X4R receiver is slightly too high to just use single LM7805. 350mA during servo movement means more that 2W of heat ((12-5) * 0.35) over single LM7805. Too much, so I will have to scavenge old models for still functional step-down converter.
One of my first DIY RC projects was a Depron Airboat I've build almost exactly 2 years ago. 12x6x2 inch hull, motor, servo, rudder and ESC. And honestly, I loved it. It was a great fun playing with it. Too bad, it did not survived very long. It broke in a middle of a lake and I decided my live is worth more. All I have left is a video
This season I started to build another Depron airboat. Slightly bigger, heavier and with more power. And partially 3D printed. Hull will be made from Depron, but propulsion and steering system will be (is) printable.
After few hours of printing time, propulsion and steering is done. What is left is to make a hull. 18x8x2 inches made from 6mm Depron. I might cover bottom with glass fiber and impregnate with polyurethane wood glue diluted with alcohol.
New thing will be a reversible ESC. I've already configured and tested FVT Littlebee 20A to act as reversible ESC and it seem to be working like expected. I only wonder how effective rudder will be when on reverse. Not much I effective probably…
And yes, STL files will be available when this is proven to be working. Everything for the community 🙂
Miniquads are fun, right? After all, there is a reasons most uf us flies 210-250 quadcopters. If so, small flying wings should be fun too! I tried that already in late 2015 and failed miserably! My design did not survived maiden flight. Well, things like that happens from time to time, so few months ago, after learning few new things, I’ve made a second attempt. And this time I’ve succeeded.
Marabou Stork, my Depron FPV airplane had a bad luck. Few weeks ago, when I was testing development version of INAV, it crashed during take off. Poor accelerometer calibration combined with a software bug resulted in heavy roll 2 meters above ground. As a result, whole front section was smashed. Everything else more less survived. Luckily, winter is coming, flying season is more less over. I have few month to rebuild the nose and glue it back into place. With some extra reinforcements.
While Marabou Stork awaits new nose, I still have some footage to show…
Depron is an amazing material. Light, cheap, waterproof, easy to process and quite durable. Almost everything in RC world can be made from Depron. All one needs is imagination, glue and proper knife. Like I mentioned few times before, I’m cheap, so at the beginning of my adventure with Depron, I was choosing cheap modeling knives. Usually no-name. They had one very serious flaw: knife’s blade had to be replaced every few cuts. And even so, cut was far from perfect.
Luckily, I’ve found a perfect, more expensive but cheaper on a long run, solution: Olfa Knives. Especially Olfa SK-9 Knife with SKB-2 Blades. They are sharp, strong and lasts for a long time. When needed, SKB-2 blade can be used without a knife. SK-9 has one disadvantage: there is no lock, so keeping blade extended all the time requires thumb to be used. And that make it hard to switch knife between hands.
But the bottom line is: I love Olfa knives. Not only when working with Depron. They are very useful with dealing with cables, unpacking and so on…
When you want to fix a problem that does not need fixing you get yourself into trouble. Like me, trying to tune perfectly fine elevator. Few seconds after take off plane dives and crashes into the ground. Wing and all the gear survived. Fuselage broke in half. Time to manufacture a new one.
Few months ago I’ve wrote about my first handmade Depron airplane. It was cool design. Super simple, with KFm-2 airfoil, durable and easy to fly. But it had few serious flaws:
motor mounted in front of fuselage is great for flight characteristics, but propellers breaks all the time. Even with prop savers,
big fuselage is not the same as fuselage with a lot of space inside.
That’s why, I have build a second Depron airplane. This time with pusher propeller mounted on a tower behind wing. Wing is almost the same design as in my first airplane. It is still an KFm-2 (Kline-Folgeman, modified) airfoil, 150mm chord, 12mm thick. But is a little shorter: 1200mm instead of 1250mm. The main difference is inside wing. Instead of carbon fiber spars I’ve used two carbon fiber 6mm pipes. That gives plenty of stiffness. Wing almost does not bend in flight, even during hard maneuvers. And generates more than enough lift to give nice, slow flying experience without danger of heavy stall. You really have to want to stall it. And event when it stalls, it recovers nicely: drops a nose, dives for a second or two, and you have lift again. No need to work with rudder, just let it dive and gain speed and then level. Continue reading RedCruiser – DIY Depron airplane for FPV
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