1:45 PM - 3:15 PM
[O11-P05] Completed in 15 Minutes! Inflatable Planetarium Dome with a Household Fan
Keywords:planetarium, air dome, scratchbuild, high school
In this study, an air planetarium dome was created that requires less manpower and time to assemble. Conventional planetarium domes made by high school students are generally assembled using plastic cardboard or other materials, but this requires a lot of manpower and time for assembly work and is prone to insufficient light shielding. Therefore, this study employs an air dome system using agricultural mulch sheets (black, black and white) and examines the convenience of the system in actual use. First, 14 unfolded hemispherical shapes were cut from a sheet and joined together to form a hemisphere. In addition, cylinders made from sheets are connected under the hemispheres to provide height. A vinyl duct was connected to the cylindrical part so that air from a fan could be sent into the dome without leaks. The planetarium dome made in this way was completed in about two months, but there were many problems with light shielding and the accuracy of the projection. In this study, three major innovations have been made since the initial idea was conceived, and the air planetarium dome method, which was commonly used, has been made easier and cheaper.
The first innovation was a change in materials. Conventional fabric materials are expensive in terms of material costs, and the thickness and texture of the fabric increases the weight of the dome, making it difficult to set up and carry around. In this study, vinyl material was used instead of cloth to solve this problem. Vinyl is inexpensive, lightweight and easy to work with, making it easy to handle even with household tools. Furthermore, by making the material thinner, it became possible to inflate the dome sufficiently with the wind power of a household fan, without the need for a large commercial blower. This change has succeeded in greatly reducing the cost and the effort of setting up the dome.
The second innovation is to improve light shielding. Vinyl material is generally permeable to light, and if outside light leaks into the interior, the visibility of the image is reduced. Therefore, a double-layer vinyl structure was adopted in this study. Different vinyl layers on the outside and inside were designed to increase light-shielding properties and keep the interior sufficiently dark even in brightly lit indoor areas. In particular, the use of black vinyl on the outside and the use of white on the inside, which is easier for images to be projected, has ensured the clarity of the images.
The third innovation is to prevent air leakage at the entrance and exit. As the air planetarium dome maintains its shape by air pressure, if air leaks in and out every time the dome is moved in and out, the air pressure inside may drop and the dome may shrink. To solve this problem, an airlock was introduced in this study. This was achieved by creating a small front room to separate the inside from the outside, with users entering and exiting in stages. This enabled the air pressure difference between the inside and outside of the dome to be kept constant and the shape of the dome to remain stable.
The above innovations were actually put to practical use at a cultural festival. In the future, research will be carried out with a view to further improving light shielding and upgrading the internal images.
The first innovation was a change in materials. Conventional fabric materials are expensive in terms of material costs, and the thickness and texture of the fabric increases the weight of the dome, making it difficult to set up and carry around. In this study, vinyl material was used instead of cloth to solve this problem. Vinyl is inexpensive, lightweight and easy to work with, making it easy to handle even with household tools. Furthermore, by making the material thinner, it became possible to inflate the dome sufficiently with the wind power of a household fan, without the need for a large commercial blower. This change has succeeded in greatly reducing the cost and the effort of setting up the dome.
The second innovation is to improve light shielding. Vinyl material is generally permeable to light, and if outside light leaks into the interior, the visibility of the image is reduced. Therefore, a double-layer vinyl structure was adopted in this study. Different vinyl layers on the outside and inside were designed to increase light-shielding properties and keep the interior sufficiently dark even in brightly lit indoor areas. In particular, the use of black vinyl on the outside and the use of white on the inside, which is easier for images to be projected, has ensured the clarity of the images.
The third innovation is to prevent air leakage at the entrance and exit. As the air planetarium dome maintains its shape by air pressure, if air leaks in and out every time the dome is moved in and out, the air pressure inside may drop and the dome may shrink. To solve this problem, an airlock was introduced in this study. This was achieved by creating a small front room to separate the inside from the outside, with users entering and exiting in stages. This enabled the air pressure difference between the inside and outside of the dome to be kept constant and the shape of the dome to remain stable.
The above innovations were actually put to practical use at a cultural festival. In the future, research will be carried out with a view to further improving light shielding and upgrading the internal images.