will give you an instant improvement in your hovercraft's performance. finger skirt which has very low drag characteristics or maybe a terrain over which you intent to operate it. 2 and 3 the illustrated example two finger top edge attachment points 48 to the trailing edge 50 of the associated inner bag panel 40 are additionally provided (in other examples there may only be one of these top edge attachments, more than two, or none at all). Contain the cushion of air beneath the craft at The two skirt pieces will melt and solder. Fill out our contact form to send us your request. Combined bag and finger skirts offer the benefits of the low resistance, conformability and ease of repair of the finger skirt with the versatility of hull design, air distribution, impact tolerance and the craft motion damping of the bag skirt. Of course, this level of precision is not required for models. This is why we don't need skirt attachments for the front nor for the rear. And while they might not be ubiquitous, hovercraft catch. For small models (up to 40 cm hull width), the height of these strips can be 10% of the hull width. We always wear helmets when using ours in the winter. Take two pieces of skirt and put one on top of the other so that the corners match. Note that the front and back of the "vented bag skirt" must be kept open to allow air to escape (see this page for more explanations). Our lightweight, We can accommodate 16 foot hulls with the cut out and complete versions. Image result for hovercraft skirt design. -Conducted researches on alternatives for the skirt material of a Hovercraft for better performance and cost efficiency.-Proposed the use of a synthetic rubber for cost efficiency and higher resistance to wear and tear.-Coupled 100cc 2-stroke engine to an Industrial blower to generate a discharge of 350cfm to provide thrust. The skirt isnt going to melt the ice after use. X. . Design. doughnut shape) of skirt material that is situated underneath the hull of the craft around its perimeter. google_ad_width = 728; What is a hovercraft? The skirt is one of the most important parts of a hovercraft because it allows the hovercraft to clear obstacles: the higher the skirt, the larger the obstacle that the hovercraft will clear. Application filed by Griffon Hoverwork Ltd, Hovercraft skirt having an inner bag portion formed of a plurality of panels with fingers attached thereto, Air cushion vehicle flexible skirt assemblies, Flexible skirt members for gas-cushion supported apparatus and devices, Float charge type skirt structure for air cushion ship, Dual stability seal skirt system for air cushion vehicle, Arrangement of seats for an aircraft cabin, Airplane wing and undercarriage construction, Elevated walkway for improved cabin height, Air cushion vehicles having flexible cushion-containing walls, Air-cushion vehicle control system by means of pylons of propellers and pylon of propeller, Method to produce system of propulsion of universal aircraft and universal aicraft to this end, Composite vehicle for traveling over land and/or water, Skirt structure of hovercraft for reducing frictional resistance, Flexible double walled skirt for ground effect vehicles, Double-air-screw drawing-in type full hovering hovercraft, Ep: the epo has been informed by wipo that ep was designated in this application, Ep: pct application non-entry in european phase. You can use other materials or other fabrics as long as they are resistant enough, airproof and waterproof, while being flexible enough to inflate. Used to contain high pressurized air . To be more precise, this tutorial focuses on "vented bag skirts", which are the best compromise between ease of design and assembly, value for money and efficient operation. Integrating advanced technology with skilled craftsmanship, each individual skirt segment is hand-fabricated to meet high quality standards. Hovercraft's skirt Skirt is made of cloth type material which does not allow air to leak through it. The Hovercraft narrow Side Segment Skirt System comes in black, but you can also Therefore, we need the top of this piece of skirt to be 25 cm (25,1 cm because you will need a margin when sewing or soldering the pieces together). I personnally learned by doing it a few times and making mistakes at first. They must be separated from the edges of the hull by 30% of the hull width. On a real hovercraft, where the semi-circle must be around 40 cm in diameter, you can go up to 12 equal circular sectors to get more precision - in that case you will get 15 sectors. but the segments have the addition of extended inner diaphragm drag flaps. Draw a vertical segment that will depict one of your attaching strips (3 cm height in my case, because my hull is 30 cm large). deformed. You read it well, this tutorial works for both ! Then, you need to choose what your hovercraft hull will look like. "alternative drive" or Hydraulic system - "Fluid power ". Usually, a hovercraft is designed to be used with a vertical propulsion system to produce lift and thrust forces. 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. Neoteric's engineers are never satisfied with the status quo. The fingers are preferably attached to the panels. of material. We will continue the tutorial with older drawings. The space between two lines, noted X on the drawing, is calculated from the following formula : (/180) r. In this example, = 22.5 because we divided the semi-circle in 8 equal sectors, and r = 3 because the semi-circle radius is 3 cm. A hovercraft is an all-terrain vehicle (water/land) that moves on a cushion of air. Stern/rear hovercraft skirt drag might be a version of torque or braking power applied. Cut holes in the plastic. Logically, the more complex your hull is, the more work and calculations you will have to do : the red hull, above left, will require only one angle template (only 90 angles), and 4 pieces of skirt, as it has 4 sides. First things first : you need to choose what your hovercraft hull will look like. 4.3 Final Design of Hull and Skirt. The QWERTOUR RC Hovercraft uses two powerful props to provide propulsion and steering. The design of the skirt mainly considers the type of flow and the number of air exit holes. To be more precise, this tutorial focuses on "vented bag skirts", which are the best compromise between ease of design and assembly, value for money and efficient operation. Remember that you will need one template for each angle value on your hull. Ideally, the pressure coming from the blower would only be somewhat greater than skirt pressure, and that would be only somewhat greater than velocity pressure of the air escaping from underneath. is investigated by the United States FBI and is punishable by up to Join the end of the semi-circle to the end of the attaching strip with an arc. Overlapping of adjacent panels also offers the benefit of a stronger multi-layer structure without having to laminate layers together (as is often the case in conventional inner bags, which increases the cost and stiffness). As said before, as you need to draw one template for each angle value on the hull, repeat this operation until you have all the templates you need. Use this arc length to divide the rest of the skirt. . Ref document number: Pay attention to the last dot that you may have added manually on the skirt profile during the previous steps - in that case, the two last lines, at the top of the drawing, will not have the same "X" gap as the others. 1. The second picture shows the final result of two 45 corners facing each other. 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. Original (factory) configuration with tigershark teeth: . whereas those fitted with bag skirts usually have square or angular when sewn or glued together, adopt the shape required. Draw a semi-circle, the center of which is exactly below the edge of the hull, and facing the end of the attachment strip. It is possible that some water gets inside the rear of the skirt when you operate it on water. A bag skirt can be thought of. Abrasion resistant Custom rubber formulation Custom skirt fabrication. In this case, the compass was positioned at the top of the drawing, right above the center of the semi-circle. The size of these holes 46 can be chosen, as in conventional bag and finger skirts, to control the pressure difference between the bag 20 and the main cushion space. variation in the exact shape and size of the skirt and structure can be This allows maintenance personnel to enter the skirt system via hull access points and unfasten finger attachments without having the weight of the skirt bearing down on top of them. If you have a hard time understanding this tutorial, or if you want help with your skirt design, feel free to contact me at diyhovercraft01@gmail.com. A skirt (10) for a hovercraft including a bag section (26) for attachment to the hull (30) of the hovercraft and a plurality of fingers (22) extending downwardly from the bag section (26). enlarge the following pictures by right-clicking on them and select "open in a new tab" or "display image". Tape the skirt under the sides of the hull. Once your dot is drawn, erase the two lines that you used to place it, to make your work easier. 1649 Tippecanoe Street Terre Haute, Indiana USA 47807-2394 It has six channels for various controls. A hovercraft is a type of vehicle that rides on air that is under pressure. Divide the semi-circle into 8 equal circular sectors, each one being 22.5. If an inner panel 40 is damaged or worn, it can be replaced individually without the need to remove and replace a large unitary panel. Are you done cutting all your skirt pieces ? , Service And since most of our hovercraft work fine without a skirt, our skirts can be detached and reattached with ease. to develop a section through the side skirt geometry, deciding The least we can say is that designing a hovercraft skirt from scratch can be confusing. The black one, as it has four different angle values, will require four templates and four times more calculations. Remember that you will need one template for each angle value on your hull. You will notice that the strip is not perfectly straight, and that there should be two strips facing each other - this was a quick draft for me, you have to do better :-). In accordance with the present invention, the inner bag portion 28 is 'tiled', as best seen in figs. Schematic diagram of hovercraft The skirt design determines the life of an ACV's to hover. the tailoring, splitting it into a sensible number of panels which, Spinners. otherwise occur if a soft skirt were used. Kofi Anguah and Nick Szapiro - Swarthmore College Computer Society If you have any questions, send me an email at diyhovercraft01@gmail.com. A development history is presented for the skirt designs of large hovercraft, with attention to the design methodology and verification techniques employed to arrive at performance improvements over several design generations. The result may contain a very small margin of error, which will have no bad consequence. 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. The angles will depend on many factors, the width of the skirt segment, the hover height, the angle of your planing surfaces etc. Therefore, you will need to use two different templates for the right and left sides of these skirt pieces. low drag hovercraft skirt segments can be changed or replaced in less than one minute no They offer a A cutting table with a NC tape-fed controller has been developed with a jet of 0.15 mm (0.006 in) diameter operating at 379 MPa (55000 lbf/in 2 ). A hovercraft is a great means of transportation. Hovercraft can be powered by one or more engines. With a pencil, draw two lines parallel to the sides of the hull. The hovercraft is then ready to glide whatever the nature of the ground: water, swamp, ice, earth etc Propulsion is provided by a propeller. With your soldering gun, slowly follow the shape of the cardboard. Finally, you obtain a vertical cut of your skirt : this is what your skirt will look like when inflated. My goal is to democratize RC hovercrafts and general knowledge about hovercrafts. A Pocket Sundial From a Broken Pocket Watch! 47751 Michigan ave. , Port Isabel, TX, 78578 Most preferably they overlap such that the aft edge of each panel lies below the forward edge of the next panel. Just remember to use the correct templates for each different angle value on your hull, and to use the length corresponding to the hull side. In addition, the invention is intended to improve the flexibility of the skirt bag. In the same way, sew / solder all the corners together to complete the skirt. Its breakthrough design and consistency pushes the hovercraft envelope even further. Draw a horizontal line above the last dot that was drawn and repeat the process to get your second mark. Therefore, I get : 22.5 x (/180) 3 = 1,2 cm. 2 and 3, the skirt 10 is of the combined bag and finger type, including a bag part 20 and, below the bag part 20, a plurality of fingers 22. The segmented skirt of the hovercraft comprises a plurality of bags, one adjacent to another, completely encircling the hovercraft body. Keep in mind that you may need a seam / joining allowance on all pieces. Use this arc length to divide the rest of the skirt. The diagram in Figure 1 shows some of the key parts of a commercial hovercraft. Assuming your hovercraft doesn't grow and shrink area due to skirt changes, the disk size is always the same. As the hovercraft lifts, the skirt extends below it to retain a much deeper cushion of air. A bag skirt can be designed to fit a variety of hull shapes. This type of skirt has a bag skirt immediately underneath the vehicle body and then a finger skirt attached to the underside of the bag skirt. 1983 The 1000TD. The skirts of the hovercraft provide the almost watertight enclosure necessary for this machine to maintain it in suspension above the ground. Combined bag and finger skirts typically comprise an "inner bag" portion underneath the craft at the interface between the bag portion and the finger portions. The continuous tube is inflated with pressurised air to provide a compliant seal between the craft hull and the operating surface. Each has its own applications. 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. Various variations and modifications to the specifically described example are possible within the scope of the invention. This is best seen in fig. Drill a few holes at the rear of the skirt, so that the water that would have entered into the skirt can flow out. (please note that the first part of this guide is outdated), If you have any questions, send me an email at, EXCEPT WHERE OTHERWISE NOTED, ALL CONTENTS ON THIS WEBSITE ARE UNDER, COPYRIGHT 2019-2023 DIY-HOVERCRAFT.COM - SOME RIGHTS RESERVED, See the full tutorial written by Ian Smith for more details, USING THIS WEBSITE COMMITS YOU TO AGREE WITH OUR SAFETY DISCLAIMER, LEGAL NOTICE AND PRIVACY POLICY. 1. A skirt according to claim 5, wherein each of the panels has a drooping trailing edge to which an associated finger can be attached. The bag section (26) includes an inner bag portion (28) forming an interface between the bag section (26) and the fingers (22). google_ad_client = "ca-pub-8402110602011712"; 2. By using this site, you agree to its use of cookies. In this tutorial we will learn how to build an Arduino based RC Hovercraft. or jack-up the craft. 4. Air is supplied to the plenum by a lift fan Note that the front and back of the "vented bag skirt" must be kept open to allow air to escape (again, see this page for more explanations). /* skirt-textbottom */ The shape of the panels 40, the position of the air feed holes 46, and the degree of overlap between panels 40 are selected to ensure that the intended air feeds are not blocked by an overlapping panel. A skirt for a hovercraft, the skirt comprising: a bag section for attachment to the hull of the hovercraft; and a plurality of fingers extending downwardly from the bag section; wherein the bag section includes an inner bag portion forming an interface between the bag section and the fingers; the inner bag portion being formed of a plurality of panels that are arranged side-by- side along the length of the skirt, the panels extending over the top of the fingers and the fingers being attached to the panels. The flange pairs coincide with the pitch of the fingers. We also sell Vanguard/Surveyor complete skirts that only need to be installed. You now have all the knowledge to design your own vented bag skirt. The skirt was an . The appearance of flexible skirts accelerated hovercraft development at the beginning of the 1960s. Sorry to say that I don't have pictures to show the sewing of bigger hovercrafts skirts right now, but the principle remains exactly the same. As you can guess, the longer sides will be sticked on the edges of the hovercraft hull, while the smaller sides of the skirt will be sticked on the attachment strips (except for the front and the rear which have no attachment strips as I explained earlier).