broken flyer
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Mini Cobra Canard Design
Hey Everyone,
Thought I'd share a couple pictures of an aircraft I built tonight. I decided to do a 50% version of an original design of mine to flight test it before building the larger one and here it is, the Mini Cobra!
Didn't get to installing the electronics tonight(going to rob the gear out of a FT Pun Jet), but hopefully they should be installed by the end of the week and then it shouldn't be long after that(weather pending) that it gets flown and we'll know how it behaves then. Initial glide tests seem promising and I'm confident it should fly pretty good actually, the only unknown quantity is the yaw stability of this design with only small vertical fins on the wing tips rather close to the CG, but that will be easy to change if it needs more vertical surface towards the back.
If it turns out that it flies as well as I think it will, I will likely be uploading plans if anyone else would like to build one, either the 50% version or the full size one
UPDATE:
Flew the Mini Cobra four times, did some experimentation and evaluated it's flight envelope/performance this afternoon. I wasn't feeling very confident about it having good yaw stability with only the little winglets/fins on the wing tips so before the first flight we retro fitted a vertical stab on the fuselage with the intent that we would remove it after we knew it flew and see if it still flew alright. The picture below is a little blurry, but I didn't realized it wasn't in focus out at the field.
The first flight was pretty short lived because I had the CG too far back, but after that we moved it as far forward as the battery could go and it flew wonderfully on the second flight. Following the very successful second flight we proceeded to remove the central vertical fin and tried it again and it was apparent that it was not stable without that so after another rough landing we put the vertical fin back on and flew it a fourth time. During the successful flights I made an effort to see how it stalled as well as rolled and it was truly wonderful. It stalls just like a good canard design should(the canard stalls first so the main wing really never stalls) and it has possibly the gentlest stall characteristics of anything I've ever flown. The roll was also amazingly axial which was slightly surprising to me since I placed the wing above the center of thrust, but it was a good surprise none the less.
Now knowing that it needs larger vertical stabilizers than the original design had I intend to redesign those/upsize them and try it again.
Below are the two best videos I have of the test flights the other day. Not great and the clouds made it hard for the camera to focus at times, but it should give you all an idea of how this bird flies. Enjoy!
UPDATE 2:
Two variations of the design flying!
UPDATE 3:
I took a couple hours today to put together hopefully enough material so people that want to start building this design can have at it!
I also decided to include everything needed to build the Mini Cobra with either the twin tail setup or the three tail setup since it seems to be pretty much split down the middle as to which one is preferred.
View attachment Mini Cobra Build Manual.pdf
If people would like tiled and or full size PDF's to use as templates I can do those as well but for me personally I find that I prefer to measure it out on a sheet of foam board if I have the dimensions rather than piece together a tiled print and then cut through the paper.
Looking forward to seeing some of these built!
Hopefully when I get a little more time up here, myself and a friend will build a couple of these planes so I can do a good build article.
Happy building!
Hey Everyone,
Thought I'd share a couple pictures of an aircraft I built tonight. I decided to do a 50% version of an original design of mine to flight test it before building the larger one and here it is, the Mini Cobra!
Didn't get to installing the electronics tonight(going to rob the gear out of a FT Pun Jet), but hopefully they should be installed by the end of the week and then it shouldn't be long after that(weather pending) that it gets flown and we'll know how it behaves then. Initial glide tests seem promising and I'm confident it should fly pretty good actually, the only unknown quantity is the yaw stability of this design with only small vertical fins on the wing tips rather close to the CG, but that will be easy to change if it needs more vertical surface towards the back.
If it turns out that it flies as well as I think it will, I will likely be uploading plans if anyone else would like to build one, either the 50% version or the full size one
UPDATE:
Flew the Mini Cobra four times, did some experimentation and evaluated it's flight envelope/performance this afternoon. I wasn't feeling very confident about it having good yaw stability with only the little winglets/fins on the wing tips so before the first flight we retro fitted a vertical stab on the fuselage with the intent that we would remove it after we knew it flew and see if it still flew alright. The picture below is a little blurry, but I didn't realized it wasn't in focus out at the field.
The first flight was pretty short lived because I had the CG too far back, but after that we moved it as far forward as the battery could go and it flew wonderfully on the second flight. Following the very successful second flight we proceeded to remove the central vertical fin and tried it again and it was apparent that it was not stable without that so after another rough landing we put the vertical fin back on and flew it a fourth time. During the successful flights I made an effort to see how it stalled as well as rolled and it was truly wonderful. It stalls just like a good canard design should(the canard stalls first so the main wing really never stalls) and it has possibly the gentlest stall characteristics of anything I've ever flown. The roll was also amazingly axial which was slightly surprising to me since I placed the wing above the center of thrust, but it was a good surprise none the less.
Now knowing that it needs larger vertical stabilizers than the original design had I intend to redesign those/upsize them and try it again.
Below are the two best videos I have of the test flights the other day. Not great and the clouds made it hard for the camera to focus at times, but it should give you all an idea of how this bird flies. Enjoy!
UPDATE 2:
Two variations of the design flying!
UPDATE 3:
I took a couple hours today to put together hopefully enough material so people that want to start building this design can have at it!
I also decided to include everything needed to build the Mini Cobra with either the twin tail setup or the three tail setup since it seems to be pretty much split down the middle as to which one is preferred.
View attachment Mini Cobra Build Manual.pdf
If people would like tiled and or full size PDF's to use as templates I can do those as well but for me personally I find that I prefer to measure it out on a sheet of foam board if I have the dimensions rather than piece together a tiled print and then cut through the paper.
Looking forward to seeing some of these built!
Hopefully when I get a little more time up here, myself and a friend will build a couple of these planes so I can do a good build article.
Happy building!
Last edited:
