CO2 dragsters are popular amongst school kids. Racing events of CO2 dragsters are mainly organized in countries like USA, Australia, and New Zealand. A 65 feet track is used for the racing event of these miniature cars. These cars are required to be light in weight. The weight factor is, however, not the only thing which increases speed. Decreasing aerodynamic drag also serves this purpose. The construction process of these dragsters is explained by taking into account all these important points.
Making a Fast CO2 Dragster
The process of designing a CO2 dragster is crucial in making it move faster. A streamlined shape and selection of light material for construction are important factors taken into account. Explanation of the designing process should provide some idea about how to increase the speed of CO2 dragsters.
Designing the Body of Dragster
Usually, 'shell' and 'rail' designs are used in the construction of dragsters. The advantage of using rail designs is that they have low mass. However, this benefit can also turn into a disadvantage, since dragsters with such a design have a fragile body. Shell dragsters are cars in which the body, including the wheels, are covered by a shell. Using a shell helps reduce the aerodynamic drag to a great extent.
In a rail design, the wheel and other parts of the dragster are exposed, which naturally increases the drag. It is possible to reduce the aerodynamic drag of CO2 cars by shaping the rear section in a boat-tail form. The axles fitted into dragster cars need to be as short as possible. Drilling the holes for axles before shaping any other part of the car is necessary; it is important from the point of maintaining the axle in a steady position.
The procedure of designing a dragster is explained in the paragraph above. Let us now understand more about how this design can be refined to reduce the aerodynamic drag. It is recommended the car has a sleek surface to reduce the aerodynamic drag. This trick or technique is used quite commonly. However, for the CO2 dragster to be far more effective (speedy), one should think about making the surface like that of a golf ball.
A golf ball is marked by presence of small pits over the surface. Air flow over the surface without these pits is laminar. These pits make the air to flow in a turbulent manner. A boundary layer formed by turbulent air flow grips the surface of dragster; this boundary layer curves behind the body of dragster which ultimately reduces the size of the drag pocket; the drag pocket formed as a result of laminar flow has a much greater area.
Instruction to Create a Fast CO2 Car
The instructions to make a fast CO2 dragster are presented in the following paragraphs. Factors which affect the aerodynamic drag are explained above. Considering these factors in the process of constructing a dragster should prove to be useful. Let us understand how to make a fast CO2 dragster through instructions presented below.
- Design of the CO2 dragster that one is about to construct should first be drawn on a piece of paper; cross-section (of the side) of this design should be drawn.
- The design that is created on paper should be used for tracing the outline on a piece of basswood.
- After tracing the outline of the cross section of the dragster on basswood, a saw blade should be used for cutting it. Holes need to be drilled at appropriate places for axles.
- It is necessary avoid painting cars with thick coats; this is because lighter the dragster, faster it will move.
- Drinking straws need to be used as bearings for the axle. The axles should be inserted into the holes and washers slid on them. Wheels have to be slid on the axles after washers have been fitted.
- It might happen that wheels do not grip the axles properly. In such cases, glue can be used for the wheels to adhere to the axles.
Process of designing the car is most important in making it move faster. Different techniques and tips that are useful from the point of increasing speed of dragster are presented in this article.