First, if you don't know much about hovercrafts skirts, I strongly recommend you to read this page that contains a bit of theory and a list of different skirts with their pros and cons. And you're done. The two videos below show two skirts made with this tutorial - one for a RC hovercraft, the other for a homemade hovercraft, the Rusalka. Join the end of the semi-circle to the end of the attaching strip with an arc. Neoteric Hovercraft, Inc. If your hull design is complex, you can have two different angle values on the same piece of skirt, as shown on the drawing on the right. A Pocket Sundial From a Broken Pocket Watch! Tape the skirt under the sides of the hull. Its breakthrough design and consistency pushes the hovercraft envelope even further. Hovercraft Skirt: Duplicate Paper. One of the inherent flaws with the original designs was the amount of clearance required between the vehicle and the surface it was to hover over. 1 is a schematic side view of a hovercraft according to an embodiment of the present invention; Fig. In some embodiments each panel of the inner bag has a single skirt finger attached to it. We currently have two. I personnally learned by doing it a few times and making mistakes at first. Divide the semi-circle into 8 equal circular sectors, each one being 22.5. Click to find the best Results for rc side skirt splitter Models for your 3D Printer. considered until the happy medium is found. When joined together by soldering or sewing, this part of the skirt will have an angle of 90. in the right places to match the lines drew previously. With a compass, measure the length of the arc marked in red. Moreover, our engineers team can also assist you in the design and development of the material (rubber coated fabric) that will meet your technical requirements. Have the ability to conform or contour efficiently To go further, the following drawings and picture can give you ideas to get smoother finishes : instead of having only two 45 pieces, you can get a right angle with four 22.5 pieces, by adding an extra piece of skirt in the middle. Joined together, these weird parts will give the hovercraft skirt that characteristic cylindrical shape. Whatever the value of the angle on your hull, divide it by two and use this result to draw the diagonal as shown. The air flow and mechanical interactions among the various constituents of the skirt are noted for the spectrum of sea state and maneuvering conditions that are . Telephone: 1-812-234-1120 / 1-800-285-3761 Fax: 877-640-8507 Our team of experts will get back to you as soon as possible. google_ad_slot = "9941476513"; Similarly, the attachment of a replacement finger 22 can be achieved relatively easily. Samples of various skirt fabric tested to destruction. Mainly a diesel engine in the mid-rear part drives the propellers. Keep in mind that you may need a seam / joining allowance on all pieces. In addition, if the top edges of the fingers are not fixed to the underside of the inner bag, relative movement of the fingers not only causes wear to the underside of the inner bag but the fingers are prone to snagging obstacles and scooping water which intrudes between the fingers and the underside of the inner bag. You can now cut the two strips and fold them in the right places to match the lines drew previously. These holes should be ~1" wide. Hand access is also facilitated through the air feed holes 46. In this case, for a RC hovercraft, we will set two strips under the hull first. Congratulations for following the tutorial so far, you're almost there. You can now cut the two strips and fold them in the right places to match the lines drew previously. The first hovercraft is delivered to the RNLI for search and rescue along the coast of the United Kingdom. Draw a horizontal line that represents your hovercraft hull. Use this arc length to divide the rest of the skirt. Our coated fabrics are made up with neoprene ( CR) or chlorosulphonated Polyethylene support ( CSM, Hypalon of Dupont) coated polyester or polyamide. Chris Fitzgerald, President Neoteric but the segments have the addition of extended inner diaphragm drag flaps. The flange pairs coincide with the pitch of the fingers. ). Return to its original shape after having been moving the centre of lift pressure over and tending to raise the craft Calculation of the Lifting Pressure 3. The least we can say is that designing a hovercraft skirt from scratch can be confusing. 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). print now Tags LRTee: Last Resort 22mm . If you follow the instructions, draw it up in section full size and then measure all the sides and diagonals you will have enough to draw up the pattern. It is possible that some water gets inside the rear of the skirt when you operate it on water. Draw two horizontal and vertical axes which pass through the center of the semi-circle drawn previously. 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). The diagram in Figure 1 shows some of the key parts of a commercial hovercraft. Use this arc length to divide the rest of the skirt. cushion. On a hovercraft the only thing that touches the ground is the skirt. Homepage: www.neoterichovercraft.com / www.rescuehovercraft.com 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. 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. This drive for excellence in engineering is reflected in every Hovercraft component, including its skirt system. Remember that you will need one template for each angle value on your hull. Hovercraft's skirt . Team involved in high speed filiming exercise. The skirt confines the pressurized air that supports the weight of the craft. Urethane coated nylon fabric, 710gsm 20.9oz or 1200gsm 35.4oz/yd, STABOND 2-PART ADHESIVE for inflatable boats, or hovercraft skirts UK-148, quart, Vanguard hovercraft skirt, cut, ready to glue, Robo Scissors, carbon and glass, with two blades, charger/AC adapter, Completed vinyl skirt for Vanguard (14ft x 7ft) - color gray. About: My name is Tho, I'm the creator and owner of diy-hovercraft.com. The skirt is in excellent condition and skirt patterns are included to make new future skirts. that will fully satisfy your specifications. The steering is a PWC type steering system with a push-pull cable moving two rudders. 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 ). Once your dot is drawn, erase the two lines that you used to place it, to make your work easier. 1 shows a hovercraft having a central hull that carries a passenger cabin 4. If necessary, add a last dot "manually" at the very end of the skirt, like I did. Special thanks to Ian Smith, who created a large part of this tutorial, for giving me the authorization to improve and republish it. EP, Kind code of ref document: From this single shape, you can design all the corners templates you need, so be sure to save it or copy it. Backed by a long history of laboratory development and on-craft experience, we can match compounds and materials to accommodate specific needs for varying degrees of ozone and oil contamination, abrasion and flagellation that may be encountered during use. Repeat the same operation for all your hull sides. however, be few enough panels to make construction of the skirt fairly 5. I'm guessing it's stiff as I know of no soft foam which will not act like an open celled sponge and absorb water. The hull is typically made of aluminium, fiberglass or plastic or a combination of them. This is certainly the most difficult step of the build : you will have to work in a smaller and smaller space as you tape the skirt. To learn more about the management of your personal data and to exercise your rights, please refer to the. The figure includes a view of an inner bag panel shown laid out flat and a section through the attachment at the finger top edge; and. And since most of our hovercraft work fine without a skirt, our skirts can be detached and reattached with ease. Checkmate Flexible Engineering is, arguably, the worlds leading manufacturer of air cushion vehicle skirt components, including parts for hovercraft and surface effect ships. Let's say we have made the template for the rear of a RC hovercraft with a 25 cm hull width. contact point where the skirt touches the ground moves. Therefore, you need to set these strips first. This helps to prevent uncontrolled leakage from the bag to the cushion that might lead to an undesirable loss of pressure differential between the bag and cushion. And while they might not be ubiquitous, hovercraft catch. Often it is This inner bag portion typically has holes punched in it to allow air supplied by the lift fan to the bag region of the skirt to pass from the bag region to the finger region and finally to the main cushion. Therefore, you will need to use two different templates for the right and left sides of these skirt pieces. 1983 The 1000TD. It must keep the skirt in place without hindering its inflation. From here, we need to put the skirt pieces together, either by sewing them or soldering them. pressure on the collapse of the skirt to provide stability, ie., when Taking a look at the skirts! In the same way, sew / solder all the corners together to complete the skirt. Bean Bag Chair. Design. 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. At least 2" from the edge of the smaller circle but still in the reinforced area, cut 6 holes in the plastic. Join the dots, et voil, you have your template, ready to be reproduced on a piece of cardboard. For example, to develop a section through the side skirt geometry, deciding First of all, choose the material for your skirt : for my RC hovercrafts, I use trash bag pieces which can be melted and joined together using a soldering gun, or K-way pieces which can be sewn together. Hovercraft Consultants Ltd was founded, specialising in hovercraft skirt design. A bag skirt can be thought of as being formed from a continuous tube (e.g. The Hovercraft narrow Side Segment Skirt System comes in black, but you can also Therefore, you need to set these strips first. Keep in mind a few things. 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. 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. Note that the diagonal musn't come too close to your semi-circle, draw your vertical axis accordingly. Use roughly 5 screws to get a tight fit. pitch (fore and aft) and roll (side to side) stiffness of the air Draw three horizontal lines like shown and a vertical axis. 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. Finally, you obtain a vertical cut of your skirt : this is what your skirt will look like when inflated. A self-propelled hovercraft having a body or hull around the periphery of which is a segmented skirt. All rights reserved. ground all the way around the craft. The fingers are preferably attached to the panels. A diaphragm in the front segments prevents them from collapsing and tucking under in the event of a plow-in; the segments stay expanded, delivering vital lift air to the front of the craft, which considerably lessens the consequences of a plow-in. 2 shows a section from the skirt of the hovercraft of fig. preferable to replace the entire skirt system rather than to replace individual segments; it The Russians with the Mars hovercraft have a stacked skirt, the top one is Zodiac-like and foam filled. Page 1 of 2 1 2 Next > Joined: Aug 2011 Posts: 91 Likes: 4, Points: 8, Legacy Rep: 49 Location: Fidalgo Island, WA rubenova . (not shown). If you used it to make your own skirt, please post a picture, it will be a great reward for my work :-). 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. The angles will depend on many factors, the width of the skirt segment, the hover height, the angle of your planing surfaces etc. From this single shape, you can design all the corners templates you need, so be sure to save it or copy it. Repeat this process to get all your dots. I don't know if it's rigid stiff foam or soft like a matress. Ref document number: For example, the panels may overlap more towards an inner (hull attachment) edge than they do towards and outboard edge (e.g. again, see this page for more explanations. The Hovercraft narrow Front Segment Skirt System has extended inner diaphragm only the three main types will be ones. This is why we don't need skirt attachments for the front nor for the rear. fore extra cushion area and thus more lift is provided at that side, Each finger is open to the air cushion on the inner side and is inflated out against its neighbouring fingers by cushion pressure. 3. You don't need to know the angles. Assuming your hovercraft doesn't grow and shrink area due to skirt changes, the disk size is always the same. The hovercraft skirt is made from a flexible waterproof . Use your compass to measure the distance between the penultimate dot and the last dot on the profile of the skirt, at the bottom left, and use this length as your last "X" gap. The final stage is the development of to get more precision - in that case you will get 15 sectors. Hovercraft are hybrid vessels operated by a pilot as an aircraft rather than a captain as a marine vessel. over obstacles so as to keep the loss of cushion air to a minimum. The newer skirt designs dont spray as much water as the old ones do. //-->, Service So ends this tutorial on how to design and assemble a custom skirt, from your own hovercraft hull dimensions.