Gliders Essay Examples
Gliders are special designs of aircrafts that are essentially modelled without the integration of an engine. In most cases, they are of various designs, ranging from paper airplanes to Styrofoam toy gliders or balsa wood gliders. Perhaps, the paper airplanes are the simplest gliders to model and fly. On the other hand, balsa wood gliders are more complex to build, but offer the most exciting form of fun for students who are eager to learn about aerodynamics. (Pryor, 2004).
The hang-gliders are piloted aircraft consisting of cloth wings and a structure that is not complex. Several hang-gliders resemble kites while others have the design of a parachute. Sailplanes are also another glider model with standard aircraft structure, model and the same flight control systems used in an aircraft (Pryor, 2004). However, they do not have an engine. The space shuttle is a model was used by the Wright Brothers to gain piloting experience before they embarked on their journey to space. They were aware that when a space shuttle returns to earth from space, it does so in the form of a glider; and between 1900 and 1903 they exercised a series of glider flights (Pryor, 2004).
In comparison with a powered aircraft, a glider normally has three forces that act on it while a powered aircraft has four acting forces. The two forms of aircraft have lift, weight and drag forces acting on them. However, the glider does not have the force of thrust that is generated by the engine in a powered aircraft (Lloyd, 2012). So as to fly, the glider has to generate the required force of lift to oppose its weight, and, therefore, must move through the air to generate the force of lift. This motion of the glider moving through the air generates the force of drag (Lloyd, 2012). Drag is opposed by the force of thrust generated by the engine in a powered aircraft.
Balsa wood is very light yet tough for its cells are big and very thin walled when viewed under a microscope. Therefore, the ratio of open space to solid matter is small making it light. In order to make the best glider out of balsa wood, selecting the best balsa for each part of the model is essential (Lloyd, 2012). The lightest grades should be selected to make model parts such as wingtip blocks and nose blocks. The heaviest parts should be selected for those parts that have to bear the loads such as fuselage stringers and spars.
Balsa is considerably a soft-wooded tree thus simple hand tools for instance X-ACTO No.1 knife with No.11 blade that are used for general cutting (Kettelkamp, 2000).. Moreover, X-ACTO No.2 knife and No.26 blade are perfect for carving while Razor saw can be of great use in case thick sizes of wood are to be used. For model construction, sanding blocks are essential mostly made from sand papers as well as plywood blocks (Kettelkamp, 2000). The grain types are vital to any modeling work since the grain direction determines flexibility. Type A-grain contains long fibers and is very flexible. This type of grain is commonly used in making light parts such as wingtip blocks and nose blocks (Lloyd, 2012). B-grain is shorter compared to type A as well as relatively stiffer around its edges. It is used to make fuselage sides, wing ribs as well as trailing edges. Type C-grain is used to build the strongest models for it is very stiff across the sheet. It is best when used to make glider wings and tails.
It is easy to make a balsa wood glider if the right approach on how to build the model is followed. The knowledge of building balsa gliders forms the platform for building techniques, flight trimming, and aerodynamics, in general (Lloyd, 2012). Several steps are employed in the construction of these gliders. The things required to make one include a printer, preferably sheets of balsa wood, sandpapers and sanding block, wood glue, modeling clay, making pen in addition to modeling knife.
The procedure of building the model entails printing the sketch of the glider plan. Using a preferable scale the plan is then placed over the wood and, pressing moderately with a ball point pen, the outline is followed. The soft balsa takes the imprint of the pen and offer a line to cut on. The grain of the wood must run along the lengthiest measurement of the piece, as it is much more problematic to cut across the grain (Kettelkamp, 2000). Cutting along the impressions then follows with the use of a modeling knife, taking several passes if need be. The pieces are then sanded into their final shape. Sanding of the fuselage and the tail follows.
The air-foil in the wings is then made by the use of the sandpaper. The sandpaper is further used to shape the inner edges to form a dihedral angle the moment the two halves will be glued together. One-half of the wing is plopped with a small block while the front edge faces away from the modeler so as the wingtip to be at the appropriate height (Kettelkamp, 2000). A sanding block is then placed vertically beside the inner edge. The edge is sand until it achieves a perfect perpendicular and flat shape toward the work surface. The same procedure is repeated with the other half of the wing. The two wings are then glued together as well as the remaining parts and allowed to dry for several hours (Kettelkamp, 2000)..
In conclusion, balsa wood became readily available in United States back in 1920s. It has since been used as a standard material for airplane modeling due to its undisputed strength-to-weight ratio. Hobbyists can make gliders that are durable using the balsa wood. Balsa wood originates from balsa trees that in the U.S, they grow in humid rain forests located in Central and South America (Kettelkamp, 2000). These trees grow scattered in the jungle and before the discovery of its potential; the tree was considered a weed. After germination of the seeds, the tree takes 6 to 10 years to fully mature whereby it can be cut having attained a height of 60-90 feet.
Kettelkamp, L. (2000). Gliders. New York: Morrow.
Lloyd, A. (2012). The gliders. London: Leo Cooper, in association with Secker & Warburg.
Pryor, K. J. (2004). Gliders. South Yarra., Victoria: Macmillan Education Australia.