Trash Bag And Foam Board Hovercraft Doesn’t Fail To Succeed. Or Fail.

When you think of a vehicle that can do it all- water, land, ice, snow and more- the hovercraft often comes to mind. And while they might not be ubiquitous, hovercraft catch the imagination of many a hacker just as it has for [JamesWhomsley] of [ProjectAir]. [James] has built a small, but just big enough hovercraft as you can see in the video below the break.

Starting with a small RC proof of concept, [James] tested out some of his favorite construction materials: foam board, trash bags, duct tape, and our personal favorite: hot glue! After a successful run with the radio controlled model, [James] set out to build a hovercraft big enough to carry a human.

The resulting hovercraft was definitely enough to take a human for a spin, despite still using RC airplane parts for power. Sure, there were a couple of instances of parts going flying, foamboard being shredded, and loss of control. Even so, the trash bag air skirt stayed intact, and the aforementioned damage was nothing some tape and hot glue couldn’t fix. [James] was back on the air in no time.

Of course, some of the very reasons that we don’t see hovercraft roaming the streets come up in the video, namely off-camber paths. But the build itself is quite good, and for those of us who’ve wondered what it takes to make a hovercraft, this video shows how the sausage is made.

This isn’t the first garbage bag based hovercraft, and we featured another RC/Arduino controlled version just a while back.

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Radio Controlled Hovercraft Apes The SR.N1

Hovercraft never really caught on as regular transportation, but they are very cool. The Saunders-Roe SR.N1 was the very first practical example of the type, and served as a research vehicle to explore the dynamics of such vehicles. [mr_fid] was looking for a lockdown project, and set about crafting a radio controlled replica of his own.

The build is crafted out of a canny combination of plywood and balsa, the latter substituted in sections within the plywood hull to save weight. A pair of brushless outrunner motors are mounted in the central duct to provide lift, fitted with counter-rotating propellers in order to avoid torque effects on handling. Steering is via puff ports a la the original design, which allows the craft to spin very quickly in place to much amusement and no practical effect. The skirt is of a colorful design, carefully assembled out of polyurethane-coated nylon.

While it’s not the quickest way to build a hovercraft, it’s all the more beautiful for its attention to the details and function of the original prototype craft. We particularly like the sharp handling thanks to the puff port design. If you’re looking for a weirder design however, consider this Coanda Effect build. Video after the break.

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Foamboard Makes For A Light Hovercraft

If we are to believe many science fiction movies, one day throngs of people wearing skin-tight silver spandex jumpsuits will be riding around on hovercraft. Hovercraft haven’t really taken the world by storm, but [Fitim-Halimi] built his own model version and shows you how he did it. You can see the little craft moving in the video below.

In theory, a hovercraft is pretty simple, but in practice they are not as easy as they look. For one thing, you need a lot of air to fill the plenum chamber to get lift. That’s usually a noisy operation. The solution? In this case, a hairdryer gave up its motor for the cause. In addition, once floating on a near-frictionless cushion of air, you have to actually move without contacting the ground. Like many real hovercraft, this design uses another fan to push it along. You can see in the video that the designer uses Jedi hand motions to control the vehicle.

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Compact 3D Printed Hovercraft Is Loungeroom Floor Fun

Hovercraft come in all shapes and sizes. and while they’ve largely disappeared as a major commercial transit option, they remain popular in the hearts and minds of makers everywhere. [RCLifeOn’s] latest project concerns a compact, indoor-sized hovercraft piloted via FPV, and it looks to be brilliant fun.

The build consists of a 3D printed chassis, with a skirt cut out of a garbage bag and held on with press-fit clamps. Twin ducted fans are employed, one for propulsion, the other for levitation. A 5GHz FPV camera is nestled on top of the rear fan housing to provide a video feed for the pilot.

The craft was somewhat uncontrollable in initial testing. Tweaks to the weight distribution and the addition of a bigger rudder helped tame the rig. [RCLifeOn] also demonstrates a unique way of balancing damaged fan assemblies in the field; it’s a technique we’ll keep in the back of our mind for future use.

The trick to a good hovercraft build is light weight, big control surfaces, and a good skirt. You can even go off-book and use the Coanda effect, if you’re so inclined. Video after the break.

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Coandă Effect Makes A Better Hovercraft Than A Quadcopter

Leaving no stone unturned in his quest for alternative and improbable ways to generate lift, [Tom Stanton] has come up with some interesting aircraft over the years. But this time he isn’t exactly flying, with this unusual Coandă effect hovercraft.

If you’re not familiar with the Coandă effect, neither were we until [Tom] tried to harness it for a quadcopter. The idea is that air moving at high speed across a curved surface will tend to follow it, meaning that lift can be generated. [Tom]’s original Coandă-copter was a bit of a bust – yes, there was lift, but it wasn’t much and wasn’t easy to control. He did notice that there was a strong ground effect, though, and that led him to design the hovercraft. Traditional hovercraft use fans to pressurize a plenum under the craft, lifting it on a low-friction cushion of air. The Coandă hovercraft uses the airflow over the curved hull to generate lift, which it does surprisingly well. The hovercraft proved to be pretty peppy once [Tom] got the hang of controlling it, although it seemed prone to lifting off as it maneuvered over bumps in his backyard. We wonder if a control algorithm could be devised to reduce the throttle if an accelerometer detects lift-off; that might make keeping the craft on the ground a bit easier.

As always, we appreciate [Tom]’s builds as well as his high-quality presentation. But if oddball quadcopters or hovercraft aren’t quite your thing, you can always put the Coandă effect to use levitating screwdrivers and the like.

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A Garbage Bag Skirt Is Fit For A Hovercraft

The hovercraft is an entertaining but much maligned form of transport. While they have military applications and at times have even run as ferries across the English Channel, fundamental issues with steering and braking have prevented us all driving them to work on a regular basis. They do make great toys however, and [HowToMechatronics] has built an excellent example.

The build is primarily a 3D printed affair, with the hull, ducting, and even the propellers being made in this way. The craft is sized to be readily printable on a 30cm square build platform, making it accessible to most printer owners. Drive is via brushless motors, and control is achieved using their previously-featured self-built NRF24L01 radio control transmitter.

What stands out among most other hovercraft builds we see here is the functioning skirt. It’s constructed from a garbage bag, and held on to the hull with a 3D printed clamping ring. Most quick builds omit a skirt and make up for it with light weight and high power, so its nice to see one implemented here. We’d love to see how well the craft works on the water, though it holds up well on the concrete.

Finished in a camouflage paint scheme, the craft looks the part, and handles well too. We’d consider a small correction to the center of gravity, but it’s nothing a little ballast wouldn’t fix. Video after the break. Continue reading “A Garbage Bag Skirt Is Fit For A Hovercraft”

Single Motor, Single Piece 3D Printed Hovercraft

RC hovercrafts offer all sorts of design options which make them interesting projects to explore. There are dual-motor ones where one motor provides lift while the other does the thrust. For steering, the thrust motor can swivel or you can place a rudder behind it. And there are single-motor ones where one motor does all the work. In that case, the airflow from the motor blades has to be redirected to under the hovercraft somehow, while also being vectored out the back and steered.

[Tom Stanton] decided to make a single-motor hovercraft using only a single 3D printed piece for the main structure. His goals were to keep it as simple as possible, lightweight, and inexpensive. Some of the air from the blades is directed via ducting printed into the structure to the underside while the remainder flows backward past a steering rudder. He even managed to share a bolt between the rudder’s servo and the motor mount. Another goal was to need no support structure for the printing, though he did get some stringing which he cleaned up easily by blasting them with a heat gun.

From initial testing, he found that it didn’t steer well. He suspected the rudder wasn’t redirecting the air to enough of a sideways angle. The solution he came up with was pretty ingenious, switching to a wedge-shaped rudder. In the video below he gives a the side-by-side comparison of the two rudders which shows a huge difference in the angle at which the air should be redirected, and further testing proved that it now steered great.

Another issue he attacks in the video below was a tendency for the hovercraft to dip to one side. He solves this with some iterative changes to the skirt, but we’ll leave it to you to watch the video for the details. The ease of assembly and the figure-eight drift course he demonstrates at the end shows that he succeeded wonderfully with his design goals.

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