Cardboard Quadcopter

If you're looking at making a quadcopter for the first time, or you don't have a ton of money then this instructable is for you!

Or maybe you're not sure that it's the right thing for you? Let me reassure you, this is a great hobby! The thing I probably love most about quadcopters, especially the bigger ones, is that they can fly in nearly any weather, and are completely stable. Another great thing is that you don't need a ton of space to fly them.

When I first started building this quadcopter I had many challenges and design flaws to overcome. For starters I had to figure out a sturdy enough frame to withstand the twisting of the motors, secondly I had to find a way to attach the motors, because you can't use the conventional screws and lock nuts as they rip off far to easily, thirdly I had to find a way to stop the vibrations from the motors traveling through the frame and messing up the gyros inside the controller and lastly I had to figure out how to make my own propellers because I broke all of my spares while testing, and because of lock down circumstances I couldn't get hold of new ones.

Supplies

1. Cardboard (nice and sturdy)

2. Receiver & controller (https://bit.ly/2KW0L8I)

3. Flight control board (https://bit.ly/2KQLFEE)

4. Motors and ESCs x 4 (http://tiny.cc/zb0hnz) (this link for a pack of 4)

5. Wood glue

6. Plastic glue

7. Wire and solder

8. PVC pipe

9. Rubber bands

10. Hot gun glue sticks

11. Lipo battery (https://bit.ly/34KzilO)

12. Lipo charger (https://bit.ly/2gC64vR)

13. A power supply for the battery charger (I found an old car battery charger that does well)

14. XT60 connectors (https://bit.ly/2hvMxlU)

15. A glue stick

16. Wooden skewers

Tools

1. Hot glue gun

2. Fine toothed saw

3. Pliers

4. Soldering iron

5. Utility knife

6. Clothe pegs

7. Drill & drill bits (2mm and 5mm)

8. Pen & ruler

9. Sandpaper

So since this is a cardboard drone we are going to be using a lot of cardboard!

Lay out your two largest pieces of cardboard and draw a large X, each arm 50cm long and 3.5cm wide then cut it out and copy it on to the other piece of cardboard and then cut that out, these will be the "frame".

Now to make the "pod" grab yourself something nice and round to draw the curve on either end of the "pod". I used the lid of a large jar. The "pod", at its longest point is 18cm, and is 8cm wide, draw and cut this out and then you'll be ready to glue.

Use a generous amount of wood glue and glue the pod to the frame. Use plenty of pegs to secure it while it dries.

While this dries take some cardboard to cut out the sides of the quad. The sides of this quad are cut 1/2 cm wide and approximately 25cm long. You will need about 50 strips of cardboard.

This next step of the "pod" is probably the most important step of the build because we are dealing with the durability of the quad. I chose to use a high strength wood glue called PVA which you can find at most hardware stores.

Remove the pegs from the frame and lay it so that the "pod" part is facing up, cut the strips of cardboard to the right lengths. Now, I haven't given you a measurement for this part, because there are so many slight variations of this cut, that the best way to do it is to measure, cut, and glue one bit of cardboard at a time. The first lengths of cardboard will be shorter than the rest, because after the first layer I extended the strips of cardboard 1 cm out onto the "pod" for more strength (see photos 4 &6). At the ends of the frame glue a little bit of cardboard so that it interlocks with the sides. I used mugs to hold down the cardboard while the glue dried. I also layered up the strips of cardboard until I achieved the height of my battery - this might vary, depending on what type of battery you're using.

Now take your second frame, remove the pegs and cut a 3.5 cm square off each arm, then glue these squares onto the first frame, that you've glued all the strips of cardboard onto. I used rubber bands to secure them while they dried. These squares you've just glued on will be what you mount your motors onto.

Now take your motors and screw on the motor mounts that came with them. Take your motors and glue them onto the 3.5 cm square you glued onto the main frame in the last step. Don't use hot glue (even though my photos show this, because the hot glue softened with the heat of the motors and came off!). Use PVA instead of hot glue.

Now that the motors have been mounted to the frame it's time to solder the ESC's (Electronic Speed Controllers) to your motors so that the top left motor spins clockwise, the top right motor spins anti-clockwise, the bottom right motor spins clockwise and the bottom left motor spins anti-clockwise. If you need to change the direction of the motors, change any two of the three wires on your ESC around and the motor will spin the opposite direction.

Now solder all the red(+) wires together and all the black(-) wires together. You will need to solder two bits of wire to connect the left red & black to the right red and black wires. Also solder two wires out the back of the "pod" to connect to a XT60 connector. Now that the wiring is done it would be a good time to insulate all the wires from each other. You will have to forgive me for not doing a neater job on my insulation, but because of the current circumstances I couldn't get hold of any shrink tubing. Electrical tape had to do.

Now that you've soldered all your wires it is time to glue on the top of the drone. But before you glue on the top cut a little notch into each end of it for the wires to go through. Also cut two slits in the "pod" lid for the ESC wires, then go ahead and glue it straight on, I used rubber bands to hold it together while it dried.

In this step we are going to make our own props for the drone with a PVC pipe. The props I made worked way better than I ever expected, even though they were created half the amount of thurst than standard props they are the most silent props I have ever flown with.

Grab yourself a piece of PVC pipe (about 25cm long), I used a 6.5 cm diameter PVC down pipe for mine. Print out the PDF found in this section. Cut out the templates, and glue (glue stick) them onto the PVC pipe - make sure that when you glue them on the pipe, two of the blades are facing left and two right. Cut the PVC with a hack saw or scroll saw or fine toothed jig saw. I used a scroll saw :) I then soaked them in some water for a few minutes to take off the paper. Use some sandpaper to sand off any rough burrs. Glue on a strip of PVC pipe on the top and back, 6 cm long. Drill a 5mm hole in the middle and three 2mm holes along the strips to thread copper wire through. I did this to add more strength.

Now to make sure the leading edge (the straight edge) is tilting up a little, you can either cut the prop in half (which shows in the last photo) before you glue the 6cm top and bottom supports and offset each blade back 2 or 3 mm (which tilts them), or if you don't want to cut your prop in half you can heat the PVC up a little with a heat gun and bend them back with a pair of pliers.

When I first made the drone I stuck the controller straight on to the top, but there was a massive problem with that and it took me a while to find a solution - the problem was that the vibration from the motors traveled straight through the drone and confused the controller gyros making it so that I couldn't even fly it! I tried everything imaginable from adding more cardboard to the frame to make it sturdier but that didn't work, to making an anti-vibration pad out of cardboard but that did nothing in the world to help it either. I then came up with the idea of making a more 'solid' pad for the controller to sit on - made out of cardboard and bamboo skewers. This pad worked really well as it eliminated the vibrations troubles.

Take some cardboard and cut out a piece (see photo #1 for measurements), large enough to glue your flight control board onto. I made mine a little tapered, just to add a bit of contrast to all the square shapes on the drone. (For this build I will be using a kk2 flight controller, this controller is great for beginners because it comes pre programmed straight from the factory.) Now dip the skewers in PVA and push them through the holes in the cardboard, work a skewer through every corrugation hole and when the glue has dried cut of all the excess lengths.

Now glue the 'anti-vibration' pad to the drone with PVA, once that's dry, glue your controller to the anti vibration with hot-glue - make sure you get it as centered as possible, the more centered it is the better your drone will fly.

Take your four wires from the four ESC's and plug them into the control board, your top left motor should be plugged into the top right port of the control board, and the top right motor should be plugged into the second port down on the right side of the control board, carry on this process clockwise around the drone. Plug your receiver wires into the controller - the wire, with one connector on either side, should be plugged into channel one of the receiver, and the other end plugged into the top right port on the control board. The other wire, with three connectors on one end and one on the other end, should be plugged into channel 2,3,and 4 of the receiver while the other end should be plugged into the 2, 3, and 4 ports below the other receiver wire.

Plug in your battery and your kk2 flight controller should boot up, it should be displaying an 'Error' message, ignore that and press the menu button, scroll down to the bottom and click on the 'factory reset'. It should then pop up with a menu for choosing which drone frame you want, scroll down until you get to Quadcopter X mode, click 'accept', and then click back and back again, go back to the menu and scroll down to the 'acc calibration'. Place your drone on a flat surface and click 'calibrate'. When that's done scroll up to the mode settings and change auto level from 'AUX' to 'Always'. Unplug your battery, turn on your controller, and then plug in the battery again. The kk2 flight controller should power on and now be displaying SAFE, bring the left hand joy-stick of the controller down to the left hand corner and the display should change from SAFE to ARMED.

You have now finished setting up your flight controller!

So now all you've got left to do is to attach your props, this is really simple, just undo the 'bullet-shaped' bolts on the top of each motor, attach your props and tighten the 'bullet-shaped' bolts back down with a pair of pliers, tighten them well or your propellers will fly off! Connect your battery and you're finished. Go try it!

Congratulations on successfully building a Quadcopter!