Introduction: Foamboard RC Glider
In this Instructable we will create a simple foam board glider for hand launches, thermal soaring, slope soaring, and high starts. Why fly gliders? They are cheap to build and relaxing to fly. It is an interesting challenge to see how long you can keep it aloft. We have kept it up for a few minutes. How long can you fly it for? It is constructed from Dollar-Tree foam board and costs less than 5 dollars for the air frame and less than 60 dollars for the electronics, assuming you have no Radio Control Gear.
Step 1: Parts List
500mah 2-3S Lipo Battery with JST Connector
Battery Eliminator Circuit or Old Electronic Speed Control
Male JST Connector
2 9 gram servos
4-6 Channel 2.4Ghz Transmitter and Receiver
2 30 inch 3/8" Wooden Dowel Rods or Carbon Fiber Tubes (Lighter)
4 20"x 30" sheets of ADAM's Readiboard/Light Poster board with paper on both sides
5 Control Horns
1/4"x 2" Spring (optional)
0.047" Music Wire
Bungee Launch Cable
Hot Glue Gun
X-Acto Knife or Utility Knife
Step 2: Mark the Foam
In this step we will mark where we will cut to construct our plane's fuselage, wing, and tail. To save paper, ink, and your time we made all cuts straight and all parts easily defined by side measurements instead of creating traditional plans that would end up being more than twenty pieces of paper. The measurements are in the pictures and a description is given for each. Use two colors to draw the outlines. The red in the diagrams is for score cuts and the black is for complete cuts.
2 30 inch x 14 inch pieces with a score cut 8 inches from one side
2 30 inch by 1 inch foam strips
Triangular piece with a score cut hinge
20 inches long tapered shape, wherever there are two red lines closely adjacent it is a 3/16inch gap between the score cuts.
Step 3: Cut the Foam
For this step you will need a sharp knife. As you cut take your time. In the diagrams in the last step black lines indicate that you should cut all the way through the foam board, and red lines mean you should cut halfway through the foam, cutting the paper on one side only. If you accidentally cut all the way through however, you can simply put packing tape on the opposite side of the foam. Once you have cut out all your parts you will need to remove the foam from the 3/16" gap between the red lines on the fuselage. Crack the foam along the red lines and use your fingernails to peel the foam away. This step will take a while but take your time; if you do a bad job your fuselage will not fold well. After you have done this you are ready to assemble your plane!
Step 4: Assemble the Fuselage
In this step you will fold your currently flat fuselage into a strong 3-dimensional shape. Start by making sure your hot glue gun is as hot as it can get and that you have an extra hot glue stick handy, you will use a lot of glue in this step. Begin by putting hot glue in one of the middle two channels, then folding the foam to a 90 degree angle so that the side of the plane (the part that has a triangle at one end) is on top of the adjacent section, similar to the diagram. Repeat this step for the other side, and fold it so that it again is on top of the adjacent section. Now you should glue one of your dowels (or carbon tubes) onto the fuselage now, starting the glue bead 10 inches from the rear of the fuselage. Use lots of glue to anchor it securely.
Step 5: Center Your Servos
In this step you will prepare your servos for instillation. First put the bind plug loop into the bat port in your receiver. Next plug your esc into your receiver in port 3 with the white wire (Signal) on the left side of the pins. Now, plug your battery into your ESC. You may need to solder a male JST connector onto your BEC/ESC. There should be a red light flashing on your receiver. Next, turn on your transmitter while holding down on the "Bind" button. This will bind your receiver to your transmitter. Make sure that your Trims are centered. To do this you will need to make sure that your trim sliders are in the center for all 4 axis on both gimbals. Now plug your servos into ports 1 and 2 on your receiver. Now place the servo arm perpendicular to the servo body. Servo 2 will use the single arm, and servo 1 will use the simple double arm. Use the supplied screws to secure the servo arms to the servos. Now you have centered your servos.
Step 6: Assemble the Wing
You now need your two 30 inch by 14 inch wing sections, two 30 inch by 1 inch spar sections, 1/4 inch thick wood wing spar, packing tape, and several extra hot glue sticks. Start by connecting the two wing sections. place the two sections next to each other, lining up the score cuts and the edges. Place a strip of packing tape on one side and flip the pieces over. Run a bead of glue in the crack then lay the pieces flat, using a scrap piece of foam to squeegee the glue, once the glue is dry add a piece of packing tape over it. You now have an extremely strong joint. Stronger in fact, than the foam itself!!! Once you have attached the pieces connect the score cuts by carefully cutting through the tape and glue with your knife, then cracking the foam so it can fold over. Remove the paper from the 6 inch by 60 inch side. Cut one of the 30 inch by 1 inch spar sections in half. Mark 1 inch back from the score cut on the 8 inch by 60 inch side at both edged of the foam and in the middle. Using a straightedge draw a line between the marks. Mark the 30 inch by 1 inch spar section at 15 inches, then glue it to the wing on the line centering it using the mark you made. Glue the two 15 inch sections on the line completing a full span foam spar. Next, we will glue the wooden spar in. Make a mark at the center of your spar and glue it behind the foam spar. For the next step you will need a decent hot glue gun. If you are using a mini hot glue gun, stop here and go find some superglue or gorilla glue, your hot glue gun will need to be able to output a large amount of glue for this step. It may also be necessary for you to get a plank of wood to use to apply pressure to the fold evenly. The two links point to videos demonstrating folding a wing. To fold the wing you will need to put glue on top of the foam and wooden spars, then fold the foam over and the score cut, with the side without paper internal. Press down and hold the wing for 30-60 seconds until you are positive the glue has cooled. Once this has cooled you will need to squirt glue between the two pieces of foam on the trailing edge of the wing, and fold it down, squeegeeing excess glue and holding the pieces together until the glue is cool. You now have the basic wing!!!
Step 7: Install the Servos
You now need to install the servos. Tie the fishing line to the elevator servo arm, and put hot glue on the knot for extra security. You can then glue the elevator servo 2 inches in front of the tail boom, with the wires towards the front of the fuselage. The aileron servo will be mounted vertically. Glue it upright, then glue scrap foam next to it to anchor it securely in place.
Step 8: Assemble the Tail
To assemble the tail you need your vertical and horizontal stabilizer pieces. Glue the vertical stabilizer to the side opposite the score cut, and make sure it is at a 90 degree angle to the horizontal stabilizer and is straight. Glue the assembly to the tail boom. Once this is glued you can move to the next step!!!
Step 9: Hinge the Control Surfaces
To hinge the control surfaces you will need a very sharp knife. Take your time. Remember though, if you cut the paper you can always use a little packing tape to fix it. You will need to hinge the elevator on the score line already cut. For the ailerons you should measure one inch from the trailing edge of the wing, then cut off the excess foam and hinge the ailerons in line with the trailing edge of the wing. The video demonstrates the process of cutting an angle for a hinge.
Step 10: Add Control Linkages
The control linkages transfer movement from the servos to the control surfaces. We will start with the elevator. First, glue the control horn to the top of the control surface of the elevator, with it's holes above the hinge, then attach your spring or rubber band to the top hole of the horn, Attach the other side of the spring or rubber band to another control horn, again at the topmost hole, and attach that control horn at a point on the horizontal stabilizer where there is a light to medium pull when the elevator is in the up position. After this, glue a control horn to the bottom side of the elevator control surface and tie the end of the fishing line attached to the servo to the topmost hole of the control horn. You should now turn your radio on and connect power to your receiver. This will prevent the servos from moving and let you center the control surface without using the limited trims on your radio. Pull the fishing line tight and tie a knot around the horn, adjusting it so that the surface is flat without you holding it. Once it is secure test the control linkage by wiggling the right stick on your transmitter. The surface should move. Moving on to ailerons; You will need two 15 inch sections of music wire, thin nose pliers, and 2 more control horns for this step. Bend one end of each of the wire sections into a "Z" shaped bend, about 1/4" between bends. Insert these ends into your aileron servos arms in the outermost holes. Glue the control horns so that the holes are in line with the hinge. Bend your wire so that it goes through the top holes of the control horns at a length where the control surfaces are level with the bottom of the wing. Complete the Z-Bend to secure the wire in place and cut away the excess wire. Test this by moving your transmitters right stick. The ailerons should move in opposite directions.
Now that all that is done, it is time to finish your fuselage. Fold the nose and glue it together, then glue the bottom of the fuselage on to the sides. On the top, cut a 6 inch long hatch and glue your receiver and ESC or BEC in. Do not glue your battery in, use tape for now, you may need to move it later.
Step 11: Attach the Wing to the Fuselage
To attach the wing securely to the fuselage we will glue it. Add lot of hot glue to a 6 inch section of the fuselage, then attach the wing and make sure it is square to the fuselage and centered. Test this joint, not too hard, but definitely test it, If it breaks easily in the workshop it will break at the worst possible moment while flying. Simple as that, on to the next step!
Step 12: Attach the High Start Hook
For the high start hook you can simply hot glue a Popsicle stick on the fuselage towards the wing where the fuselage tapers, leaving about 2 inches for the high start cable to loop around. Simple, and it works well.
Step 13: Assemble the Bungee
Next you will setup your high start. First, lay your bungee out on the floor in a straight line so that there are no tangles in the bungee. (Some troubleshooting may be required) Get a string, like the string to a kite. It ideally should be around 50m but it will work with 10m. The string should be as lightweight as possible. Now, find one end of the bungee and tie the string to it in a square knot. To tie a square knot, take the bungee in one hand, and the string in the other. Now put the one in your right hand over the one in the left and loop it under the left one, and switch which hand is holding which. Now take the one in your left and put it over the one in your right. Now bring the one in your left around and through the hole you formed. Pull tight. There are videos on YouTube if you need help. Now take a light plastic bag (Like a grocery bag) and cut out a section 10” by 15” and tie it 10”-20” down from the top of the string. Now secure the bag with hot glue for security. Finally, attach a zip tie to the top of the string so that it forms a 1” diameter circle (Oval is ok too). Now tie the string to the zip tie with a few overhand knots. Congrats, you've finished the High Start! On to the next step!
Step 14: Set Up Your Radio
Next you will attempt :-) to setup your radio for flight! First plug the servo that has the fishing line/string coming out of it (The servo that moves your elevator) into port 2 on your receiver. Next plug the servo that moves your ailerons into port 1 on your receiver. Now plug your battery into your esc and turn on your receiver. A red light should come on in your receiver (if it doesn’t you will need to male sure your receiver and transmitter). Next test your servos by moving the sticks. When you move the right gimbal upwards the elevator surface should move downwards. If it does not, use the switches below the gimbals to reverse the direction. (Hit the switch with the corresponding label) When you move the elevator stick downwards the elevator should move upwards. Next, test the ailerons by moving the stick on the right gimbal right and left. When you move the stick to the right the aileron on the left wing should move downwards and the aileron on the right should move upwards. If the opposite happens, simply reverse the ailerons through the aileron switch like before. When you move the stick to the left the aileron on the left wing should move upwards and the aileron on the right should move downwards.
Step 15: Go Fly
Before you fly though, one last thing. Make sure that your plane balances 2 inches back from the leading edge of the wing. Move the battery around in the fuselage until it balances perfectly. Do this right or it will CRASH. On your first flight give it a light toss and maintain a slight downward angle; you do not want to stall the glider. To use the high start cable anchor the bungee securely to the ground then walk back holding the zip tie until the bungee is stretched to its limit. This should be quite a distance. You can then hook the zip tie to the Popsicle stick and release the glider at a slight upward angle. Minimize how much you control the glider on the way up. Before you fly you may also want to watch a few videos on YouTube about how to fly an radio controlled plane in the case that you have never flown one before. Find a nice big field, and have a blast! If you enjoyed this Instructable, please vote for me in the things that fly contest! It means a lot.
Step 16: Modifications
Cover the foam with packing tape for increased strength
Use 2 servos for ailerons and program flaps
Add a rudder
Add a motor
Add a tow release
Make a V-Tail version
Add a MASSIVE motor for speed
Cut the wing size down
Add a camera