Fly straight: Building a balsa wood glider

Transcription

1 Fly straight: Building a balsa wood glider Equipment Glider template (page 5) printed out on A4 paper in landscape orientation Balsa wood, 2 mm, for wing & winglets, horizontal stabilizer and tail Balsa wood, 5 mm, for fuselage Craft knife Metal ruler (using a safety ruler or length of aluminium angle will protect fingers from the knife slipping) Suitable surface to cut onto, such as cutting mat Hot glue Glue stick Large elastic band Sticky tack Safety First Craft knives should only be used under the supervision of a responsible adult. Risk of burns from both the hot glue-gun and hot glue, take extreme care Check the area where you will fly your glider is clear of people and other hazards Instructions 1) Cut out the glider shapes and glue to the balsa wood using the glue stick so that the writing still shows. The fuselage shape is made from the 5mm balsa wood, and all the other shapes should be stuck to the 2mm wood. 2) Carefully cut out your glider parts using the craft knife and metal ruler. If you wish, you can peel off the paper template once the shapes have been cut. 3) Using the hot glue, glue the winglets to either end of the wing. The shortest edge of the winglet should form the new tip of the wing, and the winglets should mirror each other so the back edge of the wing is flat the entire way along. The winglets should be fixed somewhere between 25-45º above horizontal (figure 1). 4) Line up the horizontal stabilizer so the tip is pointing to the front of the fuselage and the stabilizer s back edge is lined up with the end of fuselage. Hot glue the stabilizer to the underside of the fuselage (figure 2). 5) Attach the tail piece. Make sure the sloped edge is pointing towards the front of the fuselage and that the bottom edge is resting on the horizontal stabiliser. Hot glue it against the side of the fuselage (figure 2). 6) To attach the wings to the fuselage, loop the rubber band around the fuselage holding the spare slack above the main body. Place your wings just in front of the rubber band, 1

2 then pull the band down over the wings and loop it over the front end of the fuselage. Make sure that the wing centre line is in line with the fuselage (figure 3). 7) Take a blob of sticky tack and gently stick to the nose of your glider. Make it as even as possible. 8) Your glider is now ready for launching. Figure 1. Figure 2. Horizontal stabilizer 2

3 Figure 3. Rubber band Launching To fly your glider, first find a suitable space that is clear of things you could hit including other people. Remember, your glider is relatively light weight so it will get blown around if it is too windy. When launching make sure the nose is level or slightly down, if you launch it nose up the glider may stall and quickly go into a dive. In addition, you only need to give it a moderate push to get it started. The primary source of energy driving the glider forward, making it fly, is not the initial thrust from the launch (like a bullet), but its potential energy (mass x gravity x height). Adjustments and trouble shooting 1) Adjusting your wings and nose weight: The nose weight is added to help bring the balance point (centre of gravity) of the glider to just in front of the wings. This helps the glider to be stable in the nose-to-tail direction. Try adding more nose weight or moving the position of the wings and see what crazy flight paths you can get. However, you should get the furthest and most stable flight when the centre of gravity is just in front of the wings and this is what you find in commercial aircraft. 2) Glider flies off to one side: Check the wing is lined up centrally and the angles of the winglets and horizontal stabilizers are symmetrical. Also make sure that your nose weight is even. If your glider still flies to one side, it may be the way you launch it try asking a friend to launch it and see if they get the same result. 3

4 How your glider works ) The fuselage. This links all the parts together, provides space for passengers, and supports most of the load when the aircraft is on the ground. 2) The wings. These create the lift, allowing the aircraft to fly. It supports most of the load during flight. 3) The horizontal stabiliser. This helps to make the glider stable in the nose-to-tail direction (pitch), preventing it tipping nose up or nose down. 4) The vertical stabiliser. This prevents the glider twisting side to side (yaw), so it continues in a straight line. 5) The winglets. These helps to make the glider stable in the wing-tip to wing-tip direction, preventing it rolling side to side. 6) Nose weight. This helps to move the centre of gravity forward. This works with the horizontal stabiliser to make the glider stable in the nose-to-tail direction. Acknowledgements This worksheet was developed by Paul Lancelot and Juliet Jopson as part of the Marie Curie Initial Training Network AMEDEO. The project helped develop computer software tools needed by the European aerospace industry in order to design aircraft that are more environmentally-friendly. AMEDEO was funded from the European Union s Seventh Framework Programme for research, technological development and demonstration under grant agreement no Licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, please attribute to AMEDEO ITN, EU FP7 Grant no

5 Parts in balsa wood 2 mm: Central wing section Wing centerline Horizontal stabilizer Part in balsa wood 5 mm: Scale 1:1 (needs to be printed on A4 paper size)