Calculation of the Lifting Pressure 3. Once your mark is drawn, erase the two lines that you used to place it, to make your work easier. The skirts of the hovercraft provide the almost watertight enclosure necessary for this machine to maintain it in suspension above the ground. Each panel 40 has a plurality (in this example three) of air feed holes 46 through which air passes from the bag portion 20 of the skirt to the underlying fingers 22. , Service ground all the way around the craft. Keep in mind a few things. There should, The hovercraft is then ready to glide whatever the nature of the ground: water, swamp, ice, earth etc Propulsion is provided by a propeller. Hovercraft are hybrid vessels operated by a pilot as an aircraft rather than a captain as a marine vessel. 2020 Checkmate FlexibleEngineering. Ref document number: Hovercraft development Let's say we have made the template for the rear of a RC hovercraft with a 25 cm hull width. Then turn it over like a sock, so that the solders are on the inside, for strength and aesthetics. enlarge the following pictures by right-clicking on them and select "open in a new tab" or "display image". The outer edge 32 of the inner bag portion 28 is connected to the bottom edge of the outer bag portion 26 and is connected at its inner edge 34 to the hull at a line known as the lower skirt attachment. This test rig is useful as a rapid means of determining fabric suitability for use as hovercraft skirts. Let cool for 20 seconds, then gently remove the skirt pieces that will certainly be sticked both to the workbench and to the cardboard. This is best suited to light racing hovercraft due to its low co-efficient of drag. contact point where the skirt touches the ground moves. over obstacles so as to keep the loss of cushion air to a minimum. cushion. Remember that you will need one template for each angle value on your hull. The pictures show two different hulls, made with polypropylene plates, for RC hovercrafts : - the red hull will require only one angle template (only 90 angles) and 4 pieces of skirt, as it has 4 sides, - the black one, as it has four different angle values, will require four templates and four times more calculations - and as it has 8 sides, it will require 8 pieces of skirt to cut and join together. google_ad_client = "ca-pub-8402110602011712"; If you are making a RC hovercraft skirt : If you are making a "manned" hovercraft skirt : The least we can say is that designing a hovercraft skirt from scratch can be confusing. Therefore, I get : 22.5 x (/180) 3 = 1,2 cm. 4. Fortunately, to make things easier, the skirt can be divided into several parts, as shown on the picture above : one piece of skirt for each side of the hull. only the three main types will be Finally, you obtain a vertical cut of your skirt : this is what your skirt will look like when inflated. The 1000TD, Griffon's first diesel powered craft launched. google_ad_width = 728; New segments slide into a special slot along the craft's edge without the need for mechanical fasteners, which enhances the Hovercraft's sleek, agile appearance. Like shown on the picture, use these bisectors to reproduce the shape of the hull with a smaller ratio. Hovercraft as we know them today started life as an experimental design to reduce the drag that was placed on boats and ships as they ploughed through water. The segmented nature of finger skirts also means that when a portion of the skirt comprising one or more fingers is damaged, only the damaged fingers need be replaced, making the repair quicker and simpler than with a bag skirt, where the complete skirt may have to be removed for repair. For RC models, the height of these strips can be 10% of the hull width. Sorry to say that I have no specific instructions to position the compass nor to set its spacing, I usually try several times until I get a correct arc.