Easy to Build and Fly Indoor and Outdoor Plane

A fairly small indoor plane, designed for foamboard. There's alot of foamboard on the market, I use 5mm foamboard with paper on both sides. I recommend to use the same otherwise you'll be having a hard time to get flat surfaces and good cracking edges.

The reason I use foamboard is because it is light (good for flying), cheap (good for your bank account) and easy to craft with (good for you). This also helps in prototyping, you can easily repair the plane if you crash it.

For 3D printing I have acces to 2 different printers. For the propellors I will be using our most precise printer, but for the firewall (where the motor will be printed on) I will have to see which printer is free and easiest to use.

Must haves:
It has to fly, if possible as long as the battery would last. Therefore we will be using a motor. You can get different kind of motors. I recommend brushless motors, which generally are better than brushed motors. As for control you need to have yaw control. The plane can stabilizes its roll with polyhedral formed wings.

Should haves:
The plane should be able to get pitch control from an elevator. You could also do this by turning the motor a little bit upwards (this is also called thrust-angle) It also should have a landing gear to get the landing shocks.

Could haves:
Our flying object could have rolling/banking abilities, using ailerons. Now since this is an indoor and easy to fly indoor plane, we won't be adding this. It takes some skill and the plane would become harder to build anyway.

Would haves:
If you'd like to go crazy you can add some (or a lot!) lights. Or you could make it flap like a bird, that would be amazing.

Note about the video: I had no time anymore to actually create a fresh (not too much modified) to create a new plane, so I had to do it with the last prototype. Besides that, there was too much wind (the plane really doesn't like wind) to fly it...

DISCLAIMER: With indoors, I mean gym sized indoor locations, not in house (well maybe you have a gym in your house, but I still wouldn't recommend it).

Step 1: Requirements!

Materials:

35mm x 40 mm x 5 mm foamboard with paper on both sides.
Metal wire that is less than 1 mm thick and a bit that is thicker than 1 mm for the undercarriage.
Hot Glue high temperature, the sticks that are a little bit transparant are better than the dull ones.

Tip: For finding this foamboard locally, search your crafting stores for "foamboard" or "maquette foamboard", since the boards are used mainly with maquette building.

Electronics:

To get a list with best possible motors I used the hobbyking motorfinder, check the photo to see what settings I used.

The next part is an ESC, the part that converts the power of the battery to power for the motor, based on what the receiver gets for input. Most ESC's have BEC inside of them, which eliminate the use of a separate battery for your servos and receiver. Make sure if you have it. Since this part is based on your motor, you check how much power your motor needs (in terms of amps), and if you have a brushed or brushless motor. If you buy an ESC for a brushed motor and you have a brushless motor, they won't work together. Since the motor shouldn't need a lot of power, I recommend about 6 to 20 amps ESC.

Next up we have the servos. Since the control surfaces are fairly small, you can use best 9 gram servos. You can use the hobbyking servofinder, and for the dimensions you can put in the dimensions of the holes in the plane (I made those holes specially for the servos I had laying around: 9,3mm x 21,4mm and 7,5mm x 18,5mm).

Now a battery is also very important. You don't want a battery that is too small, otherwise you won't have a lot of flight time, but you neither want a battery that's too heavy, because it won't be liftable. I also recommend a 2 cell or 3 cell lipo. 3 cell can get very strong though, so if this is your first rc plane use a 2 cell. I use a 480mAh 2 cell, and it's very good for this purpose.

Receiver and transmitter are the priciest parts. If you want to make more planes, heli or multicopters, I recommend a high end transmitter. This is so you can have more channels and more models in your transmitter. Also the transmitter is programmable, which is really useful if you have a lot of planes. If you want to go cheap, get a transmitter with at least 3 channels, and a receiver with the same. Make sure they can talk to each other (most time if they are from the same brand they will).

Tools:

Hot glue gun (high temperature)
Hobby knife
Wire cutters
Tape

Tip: If you have a metal wire that is not straight, you can cut the length you want, place one end in a table clamp, and the other end in a drill and pull it while turning the wire with the drill. The wire tends to jump when you loosen it.

Step 2: Cutting Out the Plans

For cutting I'm using a laser cutter. The red lines are full cuts, those go through the board. Black lines go through the first layer of the paper and the foam, but not the bottom layer.

A technique with the black lines I learned is that you cut the foam about half way through. Since these are all straight lines, you can line it up to a table edge, and break the last bit of the foam, following the cut. This way you won't destroy the paper.

In the plans I have the red cutting lines interrupted by small black lines. I did this so you can cut the plans in a laser cutter, and not having to worry about pieces falling out of the board. When hand cutting, you can ignore those small black lines. The other big ones, being there to crack the board, shouldn't be ignored though.

Step 3: The Wing

In the wing we have 2 different kind of breaking lines. One breaking line is for the elevator (in the back) and on the side of those you have 2 lines going over the full surface. Those are for the polyhedral (which make the wing more stable).

Tip: break the lines over a table edge.

The elevator is the first one to break. While doing this make sure it break over the line only, you might want to cut the foam until you meet the paper on the other side (don't go through the paper!). After you broke it, we need to cut a bevel in the moving part of the control surface. If this is your first bevel cut, this can be very hard to keep a steady angle. The angle you want for this cut is about 45 degree.

Tip: If you cut through the paper on the other side, place some tape. You can also add some tape if you just want to protect the crease.

After this we are going to break the wing itself. In the creases we are going to put some glue (I prefer hot glue). When still movable, we move the wing down and put the wing-wig between the end of the wing and the table. Make sure the middle part of the wing is flat on the table, otherwise the angles of the wings won't be the same and the plane will always roll & yaw one way. Do the same for the other wing. Make sure they are bent the same amount.

Tip: I tend to place stuff with some weight (like a phone) on the plane to wait till the glue is dried.

WARNING: If the wing is stuck to the table, do not pull it straight up! Use a rocking motion to get it off, otherwise you will pull off the paper. You can also roll the wing over to the lifted surface, but do it with care otherwise you might pull off the paper.

Step 4: The Rudder

Next we are going to break, cut and place the rudder. As said, we are going to break it just like the elevator. Now we are going to make a double bevel cut. On both sides of the control surface you bevel cut the board with a 45 degree angle.

Tip: Another way to strengthen the control surface it placing some glue in the crease. After you do this spread the glue out over the foam and do not let both sides touch, otherwise your control surface will be stuck!

The next thing is to place the control surface. Before we glue it to the wing, we are going to do a dry fit, to make sure the rudder will fit in the wing. If it fits, we are going to putt glue on the touching surfaces. Make sure the control surface is perpendicular to the wing. You can add some glue to the side of the control surface (where it touches the wing) and spread it out, to strengthen the connection.

Step 5: The Motor Mount

Next up: The nose with motor mount. This part contains two pieces: the motor mount and the foam board nose. The printing can take a lot of time, so make sure how you plan this. I uploaded two printing plans, one specially for my brushed motor and one more generic for my brushless motor.

The nose we have to break and crease out some foam, as shown on the photo. Make sure there is no foam anymore in the crease, otherwise you won't be able to make a good fit. After this we glue it together. Here we pull the walls over the base and glue them on top of the base. Again, make sure the walls are perpendicular to the base. If you have done this right, you should be able just to dry fit it in the wing.

You can choose several ways for the motor mount. You can 3D print it (like I did) or a bit simpler and get a piece of plywood and get the holes right. If you do this, you can bore the holes right in the place of your motor.

Now you can glue the motor mount in the nose. Make sure you do this on the side with the least amount of space in between the begin and plug, so the nose won't fall too much over the front of the wing. If your motor/propeller runs counter clockwise, turn the mount a 4 degrees to the right, if it runs clockwise turn the mount 4 degrees to the left. Also (in both cases) turn the motor mount 4 degrees upwards. You might want to test fit the motor.

When done, fit the mount in the wing and glue it on.

Step 6: The Undercarriage

The undercarriage is made out of two pieces. Front wheels and the back bump.
The easiest part is the back bump, this part is glued underneath the rudder. Don't glue it on the elevator, but you can see it has a cutout for the elevator to move within. If it's glued on, you add some glue and smear it out on the foam so you strengthen the foam board, against bumping into the ground.

The second part is the wheels. You glue two circles together (wheels) so you get two pair. Again you add some glue to the foam and smear it out to strengthen the board.

WARNING! Don't burn your hands in this step!

Now you create a hole in the middle of the wheels. This is where you are going to place the wheels on a metal wire. The metal wire you choose should be very stiff, so it can handle the weight of the plane.

Bend the metal wire in a V, and about 4 cm from the v bend the wire perpendicular down. About 5 cm down bend them straight so the newly bended pieces are both in line with each other. Place the wheels on the wire and add some glue to the ends so the wheels won't roll off.

Now you place the undercarriage in the motor mount. Check the photo's how.

Note: This undercarriage is primarily made for landing, and not for taking off.

Step 7: The Propeller

You can choose to make your propeller, like I did, or buy one from the store (with your electronics). If you buy one, look for a 6 inch diameter and 3 inch pitch (6x3) prop

This step depends a lot on how your propeller will come out of the 3d printer. If you want to, you can also buy the propellers. The size and pitch depends fully on your motor speed and strength. If you're a little bit more technical, you can use the propeller for print, I used this one. The file is added in this step, but you can get the source here.

PropellerForPrint.scad
Download

Step 8: Connecting Up Your Electronics

This is most of the time very easy. First starting with the motor and ESC. Brushless motors have three wires which you can connect with the corresponding three wires on your ESC. Brushed motors have two wires which you also can connect with the corresponding two wires on your ESC.

Next up your servos. Add the linkage stoppers to the single arms on the outmost hole, center the servo, place the arm on the servo and screw it on with the supplied screw. Now we are going to do some crafting again. In the control surfaces we are going to add some control horns. I recommend using wood or a old creditcard in this step, but I'm just going to use a bit more metal wire (check the photo's how it is done). You can also find them in your local hobby store or online. Now to connect the control horns with the linkage stoppers, I use some metal wire (again). Using a z bend to put the wire in the control horn, and you can put the other end of the wire in the linkage stopper. When doing this, make sure the servos are centered and the surfaces are flat with the wing.

Tip: To center the servo connect it to the receiver and turn on your transmitter. Now your servo will center itself (make sure you don't plug it in the throttle slot).

Last but not least: the receiver. This is where you plug in your ESC and servos. Make sure you put them in the right slot. The best way is by testing it, or checking the manual. If you don't know what slot your throttle is, take off the propeller (I recommend not putting on the propeller until you fly) and plug it in. Check your sticks on which one it is reacting, and plug in the rest. If your brushless motor is turning the wrong way, switch two of the three wires around. If you brushed motor is running the wrong way, just switch both wires.

WARNING! Do not place your propeller on until you are sure the motor is running the right way, and when your throttle is down, the motor won't run. If it does, you can get hurt really badly!

Tip: If you don't know what way the motor is running, add some tape to the shaft and let it run. You'll find out this way.

Now I like to use velcro to attach my electronics. This is also so you can move around the electronics on the plane so you can find the center of gravity. This point is right between the servos and the motor mount, marked with two tiny circles on the bottom of the plane.

Step 9: The Maiden

This is your first flight! But first, before every flight, you have to check if everything is connected right. If you push your yaw stick to the left, your rudder should go to the left as well. If you move your pitch stick down, your elevator should go up. Now your throttle should be the simplest to test.

Then fly! Make sure you have a good area outside to test it first. This is so you can feel how the plane flies before you crash it in a wall. Launch it in your hand, and the first several times you will probably crash because you need to throw it at the speed the plane should fly. You should use about half to a third of your throttle to soar around.

Good luck! I like to know how you like the design!