Introduction: Simple Rc Glider From Readily Available Materials
This is a (Hopefully) simple and easy guide to make, prepare, and fly a homemade RC (remote controlled) airplane. This is a glider type aircraft with no onboard propulsion and two control surfaces. On this airplane you will be able to control the plane's pitch (up and down) and it's yaw (left and right). However, you can also apply the same techniques used on this build to add banking (the degree at which the wings of the craft are angled) to the flight envelope. I will go into more detail later on, but for now let's get started.
Please note that there are a few parts used in this build that you may not have, unless you are already into Rc. You will need:
- an Air Hogs Titan foam plane, available from Toys R Us, Walmart, Canadian tire, Target, Etc.
- two wire clamp servo attachments, available here or from your local hobby store : http://www.hobbylinc.com/rc-airplane-pushrod-conne...
- two servos with servo arms, available from any hobby store or this site: http://www.hobbyking.com/hobbyking/store/__25456__...
- at minimum, a 2 channel radio and receiver, available from any hobby store or this site: http://www.hobbyking.com/hobbyking/store/__9041__H...
- a receiver battery pack (comes with radio)
- two 2 piece wire clamp servo attachments, available from your local hobby shop
- piano wire/wire that fits in the servo horns, available from your local hobby shop
- lead weight, available from your local hobby shop
- velcro/ hook and loop fastener, available from any hardware store
- 40-60 feet of 20 pound shock cord (20 lbs) available at Canadian tire and most hardware stores
- 20-50 feet of line (plastic dollar store laundry line works well)
In this build, we will also be using the following materials which should already be available in your home:
- packing tape
- barbecue skewers/ plastic drinking straws (straws are more flimsy)
The following optional materials are also available from your hobby shop (see step 11):
- balsa wood rectangle (1/4" 4" x 36")mall hinges
- epoxy glue
- super glue
Step 1: Preparing the Tail
Remove the horizontal stabilizer from the fuselage of the plane. Take your knife and cut off the back inch and a half (1.5 inches) of the centre beam. Shave down the remnants so that it is level with the rest of the wing. Next, use any strait edge available (for example a ruler, square, etc). With your knife, mark a straight line across the length of the horizontal stabilizer, making sure that it is at the base of the centre beam. Cut all the way through after you have checked for precision. The horizontal stabilizer should now be in two pieces. The back half will form the elevator.
Step 2: Attaching the Elevator
Take a barbecue skewer and break or cut off the pointy end. Mark the centre of the skewer and tape it to the front half of the horizontal stabilizer so that the mark on the skewer lines up with the centre beam (the groove that slides into the main body of the plane). Now take the back piece (the part which will form the elevator) and place it against the barbecue skewer in the fully pushed down position (90 degree angle to the front half), making sure it is properly aligned with both ends of the horizontal stabilizer. Tape the entire length of the top side of the elevator to the barbecue skewer/front half of stabilizer. Repeat these steps, but on the bottom side, not forgetting to put the elevator at 90 degrees to the front half before taping. You should now have a functioning elevator with more than enough throw to make it effective in the sky.
Step 3: Making the Rudder
Mark a line one and three quarter inches long level with the bottom of the existing stabilizer and about a quarter of an inch above the bottom. Mark a two and half inch line level with the top of the stabilizer and a quarter of an inch below the top of the existing stabilizer. Mark one more line towards the middle of the stabilizer, connecting the two horizontal lines. Cut out the rudder with your knife along the lines that you have made. (Note: please disregard the skewer in the photos. I have used these photos as I have no pictures without it)
Step 4: Attaching the Rudder
Cut a piece of barbecue skewer just long enough to fit inside the opening in the rear stabilizer, and tape it on firmly. You can now repeat the steps used in attaching the elevator. You should be left with a rudder that can move left and right without obstruction.
Step 5: Mounting the Servos
The best way to control a Remote control plane is to use servos. Servos are motors that respond to input from a receiver and have set endpoints at which they stop. I will be using micro servos, but regular servos work just fine, though they are heavier. You will be mounting one servo on each of the horizontal and vertical stabilizers. Use a knife or a skewer to mark the perimeter of the servos in the thickest part of both the horizontal and the vertical stabilizers, as this is the strongest part of the foam and therefore where the servos should be inserted. You can now cut out these rectangles and insert the servos. Try to insert them deeply enough so that they are flush with the foam. It does not matter which side you place them on. I have mounted them both on the same side but if you are using bigger servos it is preferable to mount them on opposite sides of the vertical stabilizer to more evenly distribute the weight. It should be a nice tight fit. Use a piece of packing tape to secure the servo solidly into both stabilizers. You can now insert the wire grip onto the servo horn.
Step 6: Mounting the Servo Horns
Unscrew the two screws that retain the bottom piece of the servo horn and use the wire that attaches the horn to the servo to poke a hole all the way through the foam to accommodate the screws. You can now attach the bottom plate of the servo horn to the top by passing the screws through the foam on both the elevator and the rudder.
Step 7: Cutting the Electronics Compartment
Take your knife and cut a section out of the back of the plane as close to the tail as possible. It should be around 9 inches long and on a curve of your preference, as long as it is above the wing. You may push extra pieces of foam out on the other side when you push the knife through. Keep these pieces as you can tape them on later.
Step 8: Digging Out the Fuselage
Use a knife or your fingers to dig out a compartment big enough to fit the battery, as well as the receiver. When it comes to mounting the battery pack, you can make a dug-out just a little smaller than the battery pack itself, so it fits snugly and will not move around during launch. You can now secure both the receiver and the battery with a strip of tape. To secure the top cover of the fuselage you can use the existing piece you have cut off and hollow it out, then use tape to create a simple hinge as well as to secure it on the other side. I have used an extra piece of skewer to create a pull tab on the tape to help open the fuselage. Now you can run the wires from the servos into the fuselage and into the receiver.
Step 9: Testing the Electronics
You can now plug both servos into the receiver. Yours may be different, but I plugged the elevator servo into channel 2 and the rudder servo into channel 1. The battery is plugged into the battery channel on the receiver. Turning the radio on will complete the connection and you will now have control of the elevator and rudder. If your radio does not connect to the receiver you will need to put your receiver into bind mode (the top small button for mine) and turn the radio on. The connection should now be complete. If not, you will need to call the company that made your radio or look up the solution online.
Step 10: Securing the Wings
Take a 2 inch long piece of soft velcro and cut it in the middle lengthways. You can now place the two pieces along the front of the wing, one piece on the fuselage and one on the wing right next to it. When it is time to fly you will place a piece of hook velcro to hold the fuselage and the wing together. Repeat on the other side. The placement of the velcro is so that the wings will not detach if the plane is launched forward, but will eject if the plane goes nose into the ground.
Step 11: Adding the Tow Point (Optional)
The tow point is the point at which you will tow the plane with either a bungee cord or a rope. You will make this tow hook out of a metal coat hanger. Use the thickest coat hanger possible, as this will create the strongest tow point. Use pliers to bend the metal until it snaps and form a piece around 5 inches long. Bend that piece at a 30 degree angle an inch and a half (1.5 inches) from one end. My photos show a 90 degree angle but 30 degrees is preferable or you will find that the key ring attached to the launch rope will have trouble slipping off when the plane reaches the apex of its ascent as you pull it along. Now you may push the long strait end of the piece into the plane about 5 inches back from the nose. This is an optional accessory and is not necessary if you will be hand launching your glider.
Step 12: Shock Cord Launching System (Optional)
Shock cord is one of the best ways to get a two channel glider up into the sky. You will need about 50 feet of rope and 50-60 feet of shock cord. Tie the rope and the shock cord together with a reef knot and tie the other end of the shock cord to a screwdriver or stake that you can drive into the ground. Tie a keyring onto the end of the rope. You can now walk backward stretching the shock cord until it can no longer stretch anymore. Hook the keyring onto the hook on the front of the plane and let it go. As the plane is accelerating, give the elevator a little bit of up to gain altitude and then the keyring should drop off, leaving your glider in the sky. I prefer to use 20 pound (20 lbs) shock cord as it is the right strength and is not too expensive (I got it for 37cents a foot.)
Step 13: Extra Mods (Optional)
This plane will now fly as it is. There are a handful of mods to make the plane much more responsive and controllable, but you will need to buy extra things from the hobby store or online. First you will need to buy a set of hinges. Any hinge will work, as long as it is small enough and has over 180 degrees of motion. You will also need a very sharp X-Acto blade and a large piece of balsa wood. If you are already into Rc planes it is likely that you already have these pieces.
Step 14: Balsa Wood Elevator (Optional)
Cut a 18.5 inch by 2.5 inch rectangle out of the balsa wood, if possible using a strait edge as a guide. This piece will be your elevator. If you do not have a strait edge (I didn't) try to make the cuts as strait as possible. If you use an existing corner of the balsa wood, you will only need to cut two edges. Now that you have the elevator piece you must attach it to the rest of the tail. Use an X-Acto knife to cut a slot in one of the thin outside edges of the length of the elevator piece, approximately four and a half inches (4.5 inches) from one end. Make a matching one on the other side. Your hinges must slide into these slots so make sure that they do. Use some super glue and glue these hinges into place, leaving about a quarter of an inch (0.25 inches) between the wood and the hinge pin. Once the super glue has dried, you will glue the elevator to the plane. As superglue melts foam, use epoxy for this part. I prefer 5 minute epoxy. Line up the edges of the elevator with the edges of the tail and mark where the hinges will go into the outside edge of the foam. Use the X-Acto knife to cut out slots along the outside edge of the foam like you did previously with the balsa wood. Now mix some epoxy. If available cover the hinge pins with vaseline to prevent epoxy from gluing the hinge. If you do not have any vaseline on hand you must be very careful not to cover the hinges in epoxy. Now, using an extra bit of balsa wood as a spatula, lay some epoxy in the slot you have made and slide the hinges into the slots in the foam, lining the elevator up with the rest of the tail and making sure you are not covering the hinge in epoxy. You can now let it dry.
Step 15: Balsa Wood Rudder (Optional)
Using the existing rudder, outline it's shape on a piece of balsa wood but extend its length to 3.5 inches using a ruler. You should be left with a parallelogram with three and a half inch (3.5 inch) top and bottom. Now, using the same techniques used on the elevator, glue two hinges equal distances from the top and bottom of the inside edge of the rudder. Once again make slots in the foam, and glue the rudder into the rest of the tail with epoxy, again making sure that no epoxy gets on the hinges.
Step 16: Attaching the Servo Horns to the Balsa (Optional)
You will need a drill to do this. You must first make marks where the two holes of the servo horn touch the balsa rudder. To do this, place the servo horn directly in line with the arm on the servo so that the wire easily slots into the servo's wire grip, then make the marks. This will avoid extra stress on the servo due to improper alignment (mine is out). Find a drill bit that is a little bigger than the screws you are using for the two part servo horns and drill out where you have made the marks on both the rudder. Repeat these steps for the elevator. Attach the servo horns to the control surfaces (rudder and elevator) and slide the wires through the servo arm attachments, but do not tighten them down yet. Set up you electronics and make sure the servos are centred before tightening down the screws on the wires (they centre automatically when the servo is turned on). Before tightening down the wire make sure that the rudder and elevator are also centred in their positions. This will maximize throws left and right (rudder) and up and down (elevator).
Step 17: Balancing Your Plane
One of the key aspects of flight is balance, or CG (centre of gravity). Cut a slot into the foam at the front of the plane along where the "fuselage" of the plane is. Then cut straight down to meet that slot from above. Dig out an area to put weights in and then make a hinge with tape to hold down the hatch. There should be a circle in the middle of the wing of the plane. Add weight to the weight compartment until the plane sits level when you hold it with two fingers in the middle of the circles on the wings. It may take time, but be patient. You can now hold the hatch closed with a piece of tape.
Step 18: Controlling the Plane
All control should now be on the right stick of the radio. To control the plane you will control the servos, which will alter the plane's aerodynamic properties, changing its trajectory. Pulling down on the control stick on the radio will move the elevator up, making the plane climb. Pushing the stick up will make the plane go down. I will explain why in the next step. Conversely, pushing the stick right on the radio will move the rudder right, and turn the plane to the right while pushing it left will move the rudder left, turning the plane to the left.
Step 19: Understanding Aerodynamics
You may be wondering why pushing the rudder up will move the plane up, and pushing it down will move it down. When the air moves over the elevator (which is in the up position), it is forced up. This wind pushes the elevator down, pitching the nose of the plane up, as if it where on a 1900's scale. The extra force pushing down on the elevator equates to adding more weight to one side of the scale (in this case the back), pushing the other side up. Then the wings of the plane create more lift than normal because wind is hitting the bottom of the wings, and the plane goes up. It is the same effect for when the elevator is pushed down, but the effect if reversed. The wind pushes down on the wings, pushing the plane down.
Step 20: Flying the Plane
A glider is just about the easiest type of plane to fly. They are generally lofty and easily controlled, but that does not mean that they do not take any skill to fly. When flying this plane, it is important to remember that the plane needs airspeed (air moving over the wings) to fly. When the plane loses airspeed and can no longer generate lift, it will fall until it can regain airspeed and recover. This is called a stall. Gliders will generally self level to a degree, because of the dihedral (angle at which the wings are placed) of the wings. At the moment of a stall, you will most likely lose control of the plane temporarily, but will regain it when the plane regains airspeed. The important thing to remember when this occurs is to Not Panic. You will regain control of the plane and be able to save it by countering the way the plane falls with the elevator and the rudder.
Step 21: Flying the Plane
As I have explained in the aerodynamics section of this build, moving the elevator up will make the plane gain altitude and moving it down will make the plane loose altitude. Moving the rudder right will turn the plane right and moving the rudder left will turn the plane left in the air.
Step 22: Landing
Landing is the most important part of flying Rc planes. Landings are relatively simple if done properly. The important thing to remember is that you will most likely crash a few times when learning. However any landing you can walk away from is a good landing. You must bring your plane in towards you (make your approach) while having it slowly descend. Once the plane appears to be heading straight toward you, you may think that the plane is going to hit you. However if you can see the side of the plane that is closest to you the plane is going to pass beside you. As the plane gets closer to the ground you will have to flare, or tip the nose of the plane up to make a smooth landing. If you do this you will have a smooth landing. If you do crash, however, the wings of the plane will eject themselves out of the fuselage, reducing the damage done to the wings. For more information on beginner flying, a Youtube channel called Flite Test has a great series on the basics of flying Rc planes and helicopters.
Thank you for looking at my Instructable. Hope you have as much fun making this plane as I did, and just remember that if at first you don't succeed, try again. Happy building!