Introduction: The Cardboard Canard (Canardboard)
Do you have time on your hands? In these strange times I certainly do, which is why I took on this project. However, if you're like me you don't have a ton of cash on your hands, and rc planes can be absurdly expensive (and therefore horrifying to crash).
I have built many remote controlled planes out of inexpensive materials in the past, but I wanted to design one of my own, and make it possible for anyone to build. I created the Canardboard with basic building strategies, supplies, and most importantly for all of you, inexpensive electronics. I hope in this project I can inspire you to try a similar project, and teach you a little aviation history.
But before we get into the build, you may be wondering, "what is a Canard?" The origen of the word canard comes from the French word for duck, and was given to these planes for looking like a duck with its neck stretched out in flight (bit of a stretch, no pun intended). A canard is not necessarily a plane, though the word can be used to reference the entire plane, but rather a unique part of certain planes. If you look at the title picture, the Canardboard looks nothing like a normal plane. The piece that gives it its name, the canard, is the small forewing up on the very nose of the plane. Historically, canards are relatively rare in aviation, for some reason or other, but the very first plane, the Wright Flyer, was controlled not by a tail with an elevator and rudder, but with a canard situated in front of the plane, and flown right in my home state of North Carolina. Canards can serve as control surfaces, provide lift, and increase maneuverability.
After the Wright Flyer, not many canards were common or mass manufactured until the release of the Saab 37 Viggen, a sweet fighter jet. Since then, many fighter jets, bombers, etc... have sported canards, alongside more conventional planes such as the widely popular Long-EZ.
With all of this in mind, and some experience from building my own designs and Flite Test planes, I set out to build a simple cardboard canard rc plane. If you don't want to add electronics, the Canardboard makes a great chuck glider.
Disclaimer: I don't have a fancy camera and am not an acclaimed photographer, these photos are meant to inform, not look pretty. Flight (and crash) videos are at the bottom! (if you aren't actually going to try to build)
Like I said, the materials and tools list is pretty basic:
- Cardboard (no duh)
- Packing Tape
- Hot Glue (a lot of it)
- Velcro? (I didn't but it could be helpful for holding down the battery)
- Bamboo Skewers (just for support if desired)
- Propeller (the size I used)
- Hot glue gun
- Hobby knife
- Small Screwdriver
- Pliers(not necessary but helpful to cut push-rods)
Electronics: These are the only real cost. Flite Test has put together power packs, which I recommend, but supplies can be got for cheaper from other stores like Hobby King and Amazon.
- Flite Test Power Pack (slow flyer version, for a little more punch, look at the C pack)
Or your own:
Step 1: Plan (just a Little)
Before I began building, I did some research! My plane is very similar to Andrew Newton's Canard Pusher, which inspired much of my build. I used his basic dimensions, and then scaled it up a tad with a little cross multiplication. You can do the same, depending on what size plane you are going for. I made mine a little too large for the electronics I was using.
Along with Andrew Newton's work, I also used skills and techniques created by Flite Test, and I recommend watching one or two of their build videos, just look them up. If you really are inspired to get into model aviation, they are the guys to talk too. They offer foam board kits and plans, electronics, materials, tools; everything, and they have a great youtube channel and customer service.
Finally, I used a little online Center of Gravity calculator, which will be explained later.
Step 2: Begin the Build: the Fuselage
This was pretty much the simplest fuselage ever. It can be a rectangle or a triangle, but because it is so much easier to build with cardboard, and usually a bit stronger, I went with the triangle.
The fuselage ended up being about 30 inches long, and building it was simple.
I simply cut out a rectangle 30 inches long by about 7 inches wide, divided it into 3 equal sections longways (around 2.5 inches, I recommend 2), and made score cuts along these lines. *A score cut is when you cut about 50 percent of the way through the cardboard, so that it folds easily along that line, without warping or breaking.
To finish the spar, I folded those score cuts so the sheet made a long triangle cylinder thing, I don't know what you call it, and hot glued all the way down the meeting of the two sides, as seen in the picture. I then put packing tape down the length of that joint, which gives it more strength in some ways than the hot glue.
There are better ways to make a fuselage, because cardboard buckles so easily, but I was sticking with the cardboard theme.
There, first step done, pretty easy so far.
Step 3: The CANARD
The building of the Canard is one of the most difficult parts, but if you have a little experience building Flite Test planes, it's easy, and if not, anyone can figure it out. Still, let me know in the comment section if you decide to build and my instructions are not clear enough.
This wing for me was 5.5 inches long, and 18 wide. I built it with an airfoil, but without any layering on the bottom, as you will see in the photos. The key to making Flite Test style wings is to make 2 score cuts along the bottom of the wing, the second around 1/3 of the way back from the leading edge (the edge towards the front of the plane). Remember the score cuts don't go all the way through, but help the cardboard fold cleanly. If you happen to cut all the way through, just put tape along the cut on the side you didn't want to cut through.
Then, you should practice bending those folds over a couple pieces of cut out cardboard, so that the cardboard fits in the middle section made by those two score cuts, as seen above. Once the wing is starting to hold shape, fill the score cuts with hot glue, and then quickly press it over the cardboard formers, so that the front and back edge are touching the table. Be careful not to let the wing get stuck to the former, unless you are doing the entire wing at one time, in which case the "former" will become your spar.
I, however, did this wing in two parts, so after carefully creating each half of the wing, I cut out a couple of strips of cardboard 18 inches long and the width between my score cuts, glued them together for a spar, and then hot glued the two sides together over and to the spar, using a healthy amount of tape and glue.
Bam, the canard is finished, all you need to do is mount it to the fuselage. You can just slap that sucker on there with glue on every contact point, but make sure your angles are 90 degrees, so that the wing is nice and square.
Step 4: The Main Lifting Wing
The main lifting wing, though a little bit harder to cut out, should actually be easier to build than the canard. This is a true Flite Test style wing, so once again, if my instructions are not clear, watch one of their build videos(go right to 17:00.)
Ok so the dimensions of the rear wing(s) are much different than the canard, as you can see in the first image. The dimensions of the actual airfoil, the longer part, are 7 inches by 18 inches. The smaller part should start from the base of one side of the wing, the middle of the plane, and be 5 inches wide and 14 inches long. These two pieces need to be connected.
Then we will do the airfoil score cuts, along with a score in between the two pieces. Remember that a score cut goes about 50 percent through the cardboard, and allows it to bend cleanly. If you happen to cut all the way through, don't worry, just tape on the outside. The side you should be cutting on while be the inside of the wing, once it is folded over. That middle score cut, the one that is really big in the photo, needs to be able to fold the 5 by 14 almost flat with the underside of the actual wing. The other two will be like the Canard score cuts. After cutting out both wings, we need a spar the size of that second space created by the score cuts, and 28 inches long. I cut out three strips of cardboard this size and glued them together for the spar.
Now we are going to fold the wings into place. Look carefully at the pictures above, to make sure you are doing it correctly. I recommend doing one wing at a time, but remember both will be on the spar, so the spar should only be half covered by each wing. Also, practice folding the wing over, and when you are ready, glue the spare to the top of the wing (the bottom being the 5 by 14 and the top being the actual wing), in between the score cuts identified above. Then fold the wing over onto the bottom, putting lots of glue on the exposed side of the spar, and a healthy bead along the back where the two should join. I put markers on the image of my wing to show you where to glue.
Then fold the second wing over the spar in the same way, remember these two wings are facing the same way, not like a helicopter, and glue and tape the wings together wherever the edges meet. Now you can glue it to the back of the fuselage.
I was super happy with this wing design, it is remarkably strong. Halfway there!
Step 5: Vertical Stabilizer and Finding the Center of Gravity
Making the vertical stabilizer will be a welcome break from the difficulty of building wings. I cut out a 9 inch long, 8 inch tall piece of cardboard, and cut a line to about 4 inches from the top corner. Especially with a plane like mine, which has no sweep in the wings, it is important to have a pretty good sized vertical stabilizer on there, to keep it going straight. I then cut the basic shape of the airfoil out of the bottom, situated it over the back wing, facing forward and straight along the middle of the plane, and glued it down, using a triangle to make sure all the angles were 90 degrees. I then reinforced it with a couple of cardboard strips on the wing.
Then I went back and found that mark for my center of gravity I had found online. On the site I used you just plug in dimensions and it will give it to you. BTW, LE means leading edge, or the front side of any wing.
I took an old battery and taped it so that the plane balanced along that line, and then hopped outside for some test glides. I recommend grabbing a family member, and tossing the plane back and forth about 20 feet. Be careful catching! Remember the little front canard is not all that strong, though the rest of the plane is pretty tough. If the plane nose dives when thrown, the center of gravity is too far forwards(nose heavy), and if it points its nose up and stalls, it is too far back(tail heavy). Thankfully, canards give rc planes really gentle stalls, for the most part, but still, you want to err towards too far forwards rather than too far back. As the great Josh Bixler says, "A nose heavy plane flies poorly, a tail heavy plane flies once." - (in like all of his build videos, every time he makes them)
You can mark that new found balance line and cross out the old one go inside to start electronics, leave the battery on and have fun chucking your Canardboard.
FYI if you want to do a paint job, you will need to cover the entire plane in packing tape, because paint makes cardboard warp when applied directly, and will ruin the wings.
No problem, right? (now comes the trickier stuff, but trust me, its worth it)
Step 6: Servo Installation and Control Surfaces for the Canard
The first image you see is one of the control surfaces for the Canard. The Canard will need two of these of equal size on either side of the fuselage, on the back of the wing, to serve as an elevator for the airplane. I did about 1.5 inches wide, as long as fit on the wing. These two surfaces will be connected with the same push rod, which you can see in the second picture. To do this you will need to fold one in half, and give it Z bends so it will connect to the little arms on each control surface. Then you will need to attach the bent push rod to the servo, slide the ends into the control arms, glue those onto your individual surfaces, and then cut a hole for the servo, where in a fixed 90 degree position, it will keep the surfaces flat like the rest of the wing.
I ended up having trouble with this servo, which led to a solid crash. I recommend testing each servo to make sure it has full range of motion. For all electronics, please watch the Flite Test build video, I was able to do this from experience, but for clear instructions, watch the video.
Step 7: Main Wing Aileron
Since this plane has no rudder, the Ailerons are the only way to turn. This type of plane is called a Bank and Yank, which just means that to turn, you have to bank the entire plane over to the side you want to turn with the ailerons, and then pull back on the elevator to make the plane make a semi horizontal loop, turning it, you will see what I am talking about in my flight videos.
Anyways, to make the ailerons, you need to do the same thing you did for the elevator, but farther out, and on the back wing. You then attach servos in a similar manner to before, but this time out on the wing. I fed the servo lines all the way under the wing, taping them to the bottom, and using a Y connecter to attach the two to one channel. If you do this, you will need to adjust the servos by actually unscrewing and reattaching the servo arms in the angle you want, once you plug everything in. Once again, check out that Flite Test video.
You are almost finished!
Step 8: Motor Mount and Electronics Adjustment (last Step)
I was pretty proud of myself for this motor mount. I created a cardboard triangle similar to the fuselage, but just small enough to slide into the back of the plane.
I then attached the motor and firewall, being careful to feed the esc through the triangle so that it would go back into the plane. After that, I opened a little hatch in the side of the fuselage where I could connect everything, and did some servo tests and adjustments, opening up the throttle, connecting my transmitter, and all that jazz. Once again, please check out Flite Test's video if this is your first time doing this.
I then fed the battery line as far up towards the nose as I could, to help myself keep that center of gravity, and ended up just taping the battery to the top of the fuselage. Even after that, I ended up needing a couple of spare batteries to be jammed into the front of the fuselage so that the plane would balance.
And TaDa! I was finished. All of the servos were working fully, though the elevator was having a little trouble, but I attached the propeller and the motor was going great. Now the nerves were kicking in.
Step 9: Maiden Voyage, a Tree Crash, and a Good Landing... (pretty Standard Flying Session for Me)
Go out there and fly! If you don't have any experience flying, this will inevitably result in a couple crashes, but don't be disheartened. When I first flew, I crashed many times, once hitting the ground, taking off again, and then having the plane fall in half midair from the damage done by hitting the ground.
When a DIY plane crashes, just rejoice that you didn't buy a 200 dollar ready made airplane, rebuild the broken parts with cheap cardboard, and go out there and fly again!
This is a fantastic hobby, with a great community, tons of forums, how to videos, etc... If this piqued your interest in the hobby of rc flight even a little bit, make sure to check out Flite Test's channel and website. They have everything you need to begin, and tons of cool projects for advanced flyers.
I had a blast creating this project, and I hope you all enjoyed, maybe got inspired, and learned a little aviation history. Make sure to share if you end up building a Canardboard, and vote for me in the competition! Stay safe and keep DIYing.
Second Prize in the
Cardboard Speed Challenge