My interest in hovercrafts was first incited by Junkyard Wars. I absolutely loved that show. From the constantly changing cast of characters to the equally unique challenge posed every week, I couldn't get enough of the weekly scrap heap showdown. I really wanted to make my own version of whatever the teams where creating any given week, but the hovercrafts really caught my attention. Something about the odd way hovercrafts slide across the ground like everything is covered in ice caused dreams of such a machine for me to pilot. I'm a little big to ride the radio controlled hovercraft that resulted from my obsession, but it's still a fun vehicle to drive around...
For a dimensioned drawing, check out my website: thewidgetforge.com
For a dimensioned drawing, check out my website: thewidgetforge.com
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The design is based around an 0.049 cubic inch un-throttled Cox engine that came off a control line airplane. It is very powerful for its size and can really move the craft along. Unfortunately, the downside is often difficult to start, especially if you feel the urge to run the craft in the cool air of fall. The glow plugs which cost about $10 and are difficult to find also burn out very easily. There is a fine line between enough juice to start the engine and a fried plug. It would help to have a larger, throttled engine for the greater control and less finicky starts. If you're interested in a Cox engine, eBay has many on sale, often in lots with plenty of extra parts included.
To help with the control issues of an un-throttled engine, I came up with the most unique part of the design: The radio controlled deflector which splits the air between thrust and lifting. It can deflect a maximum of 50 percent of the available thrust to the lift the craft or close off the lift duct completely. While it lets you control the ride height of the craft to some extent, it is most useful for panic stopping by completely cutting off air to the skirt, allowing the craft slid to a stop on the ground.
Steering consists of two balsa uprights which support the two rudders. The rudders are two inches wide and provide plenty of maneuverability, although more rudder surface would probably make it even more maneuverable. A cowling would likely make the rudders more effective too, but the hovercraft is very maneuverable as it is, so it isn't really worth the added frustration in starting the engine to add one.
Materials and Parts
The body is pink insulating foam from a local home center. This stuff works great for this purpose: it is easy to work with and quite stiff on its own. It comes in a variety of thicknesses and usually two foot by eight foot sections. The one inch thick foam is plenty strong for a craft this size. The rest of the structure is made of 1/8 inch thick balsa and, for the engine mount, 1/8 inch plywood from a local craft store.
The remote control system is a two channel set-up meant for cars, boats or other crafts that ride on the surface. It has a range of about 100 feet which is plenty for this hovercraft. The 2 oz fuel tank, fuel lines, fuel, control horns and pusher prop were all bought online at an RC specialty site.
To help with the control issues of an un-throttled engine, I came up with the most unique part of the design: The radio controlled deflector which splits the air between thrust and lifting. It can deflect a maximum of 50 percent of the available thrust to the lift the craft or close off the lift duct completely. While it lets you control the ride height of the craft to some extent, it is most useful for panic stopping by completely cutting off air to the skirt, allowing the craft slid to a stop on the ground.
Steering consists of two balsa uprights which support the two rudders. The rudders are two inches wide and provide plenty of maneuverability, although more rudder surface would probably make it even more maneuverable. A cowling would likely make the rudders more effective too, but the hovercraft is very maneuverable as it is, so it isn't really worth the added frustration in starting the engine to add one.
Materials and Parts
The body is pink insulating foam from a local home center. This stuff works great for this purpose: it is easy to work with and quite stiff on its own. It comes in a variety of thicknesses and usually two foot by eight foot sections. The one inch thick foam is plenty strong for a craft this size. The rest of the structure is made of 1/8 inch thick balsa and, for the engine mount, 1/8 inch plywood from a local craft store.
The remote control system is a two channel set-up meant for cars, boats or other crafts that ride on the surface. It has a range of about 100 feet which is plenty for this hovercraft. The 2 oz fuel tank, fuel lines, fuel, control horns and pusher prop were all bought online at an RC specialty site.
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They also sell it at the Harbor Freight stores for less then 10.00, if you are fortunate to have this kind of store near you. I don't. so I paid the premium price, but have more than got my money's worth for the many projects I have used this on.
One caution when using this wire, it is possible for it to "break", when making tight bends and will leave a wickedly sharp end when it does, so use with care, and use safety glasses when working with stiff wire, as it can easily poke you in an eye or other places for that matter..
Just thought of another use that I have used coat hangers for, and that is to put a straight length into a drill and use it to mark holes like when locating a place to run cables, heating ducts, etc This will drill through the depth of a 2x12 easily, so it will drill through your floor like butter and just leave a tiny hole if you cannot use that location.This flag wire should work well for this application. This is a great tool when working alone, as you can make up a bunch of them about 12" long, drill them in to the floor to mark your locations, remove the drill with them still in the floor, and then go locate the other end in the basement, crawlspace, and make sure that you are in a good spot before making a larger hole. Use a side cutter or like tool to cut the rod end at an angle to make it drill better. You will be amazed at how well it drills through most any floor, and even allows you to drill in tight places, as you can literally drill around corners, the wire is that flexable.
Well, they don't call me "motor mouth" for nuthin.......
Dan