So You've Always Wanted a Hovercraft... (Video)

Video So You've Always Wanted a Hovercraft... (Video) 66

Posted by Roblimo on Tuesday May 21, 2013 @02:22PM from the it's-all-about-the-air-cushion dept.

Video no longer available.

What little boy or girl never wanted a hovercraft? Something loud that could travel over water, pavement, maybe even over a plowed field or through a swamp? Ben King obviously wanted one, so after he grew up and got his PhD in physics and found a good job, he founded Lone Star Hovercraft. Timothy Lord interviewed Ben at the Austin Mini Maker Faire, and we also found some video of Ben flying (is that the right word?) one of his hovercraft on a lake that we spliced into the interview to liven it up a little. Vroom!

Ben: My name is Ben King. I’ve got a small company called Lone Star Hovercraft, and this is one of our prototypes we’ve been recently developing. It is built using what you will probably call pretty conventional construction techniques. It is just a thin layer of fiberglass on a foam core. So it is very light weight and very strong. The hovercraft itself the whole weighs about 150 lbs. And the engine about doubles that; it is about 300 lbs., ready to fly. So it is very strong, but very light weight. We are working on a few projects. We do some that are conventionally built; we are also working on some projects that are designed to be more like a quick build kit. Because these take anywhere from six months to even a couple of years to build. There are people who want to be on the water, and want to fly but don’t have quite that much time to build from scratch. So we are looking at both conventional hovercraft and also more of a kit type hovercraft just like quick assembly.

Tim: Now if this will take so many months to build, how long can it take to learn those techniques? This is your first one, is it your fifth one?

Ben: This is the third full-size hovercraft I built. I started with plans from a couple of companies, and they really spell out all the processes you use, all the materials so it is a good way to learn – building from plans. And I started even before that doing radio controlled hovercrafts, so everything from electric motors using radio controlled airplane parts up to engines on the leaf blowers and weed whackers and things like that.

Tim: How about that? You’ve got an engine back here. What kind of an engine is this?

Ben: This is a Generac brand engine it is 40 hp. It is a 1 liter V twin off of a basically it is the largest consumer grade generator you can get. And you could also source these engines relatively cheaply and they are very quiet, very reliable. And it is a really good power plant for a hovercraft this size.

Tim: Now you mentioned the idea of making kits. And you’ve got a model over here. Can you talk about modeling?

Ben: Sure, so this is a ½ scale mockup of a kit that I am working on. It is made entirely from a CNC router cut plywood. And the idea is it goes together much like a IKEA furniture, so it all slots and grooves. And there is really minimal measuring, minimal cutting - you basically will get the kit and put it together and hopefully, customize it to make it your own, with your own power plant, your own paint things like that. But the idea is to take a lot of the grueling work out of the process, and get you the fun part faster.

Tim: So what would people need to add if they bought a kit to make a hovercraft like this? What parts would you include and what parts would someone else need to buy?

Ben: We would try to include most of everything you would need for the full kit. So basically the whole kit, and then probably also the engine is an option, and then a reduction drive that slows the propeller down, propeller and then also the molded ducts so that is the duct in the back there, that will be part of the more or less standard kit. And for customization, you could add whatever kinds of controls you like, whatever kinds of paint jobs you like, things like that.

Tim: Now this boat, how maneuverable is it, compared to a canoe or a row boat?

Ben: It is very maneuverable once you have the knack for it, it takes a little bit of practice, but it is often compared to flying a bar of soap. So you have to look as far ahead as you can when on the water, or wherever you are and look for obstacles coming up, and you have to turn in advance, so it flies like a spaceship or an airboat, you turn and you push in the direction you want to go. And so you don’t have the steering that you are used to in a car or like the brakes where you have instant feedback. You really got to anticipate where you want to go and fly ahead about 10 seconds.

Tim: For propulsion, you have only got the thrust in one direction?

Ben: Right, right.

Tim: How much that of that motor’s 40 hp goes into actually lifting the craft?

Ben: About a third is the general rule of thumb. So about a third is directed beneath the craft and the lift air box that you see in the back. Part of that actually inflates this vinyl skirt, about 10 percent of the air, that’s actually sealed, so the remaining 90 percent goes beneath into the center of the craft, into what’s called the plenum that actually lifts it.

Tim: Is the skirt your own design as well? It is the whole thing?

Ben: It is pretty standard. It is called a bag skirt. So these are pretty standard designs.

Tim: And you described this as a homemade project? Is it literally built in your garage?

Ben: Built in the garage, yep. This is the third one. I’ve got a decent garage now, so I build there. The first one I built in a living room of a third floor apartment, and lowered it out the balcony window.

Tim: You must have a pretty big staff?

Ben: I had some buddies help me out. Yeah. So it is home built so it is built in the garage, and you really can make some pretty cool stuff just in the garage with everyday things you have around the house.

Tim: Now where are you going to actually drive your hovercraft?

Ben: Usually it is licensed as a boat, as you can see, it has got boat tags for the state of Texas. You can ride them pretty much on any reasonably flat surface, so grass, ice, mud. There aren’t a lot of public places you can ride, like on grass, or land. So generally they pick a lot of water. That is the most readily available place to go. So lakes and rivers.

Tim: Was licensing a hard thing to get done?

Ben: Not at all. In Texas, it is really very easy. You license it as a homemade vessel, you basically tell them how much power it has, how much it weighs, and that’s pretty much it.

Tim: And you are here at the Maker Faire, why so?

Ben: Well, I like the general atmosphere, it is really exciting, and also we’ve been doing this for a long time, using really conventional methods, and what I find is it is really exciting to see all the new tools that are becoming available, even just in the last two or three years. So we are already using a CNC router, we use water jet cutting, we are starting to get into 3D printing, so there is a lot of really cool technology here that can be used directly in making hovercraft and vehicles like this. So it is really cool to see what’s cutting edge and what people are doing.

Tim: I know you can’t pin down a price on a product that is not out for a while, but in general, what sort of price comparisons might somebody find in looking at a new hovercraft versus what you hope to do in making the kit?

Ben: We are hoping if you look around for production turnkey hovercraft they start at around $20,000 or a little bit less – it is pretty high for a weekend vehicle. We are hoping to come out with a kit that might be like a third to less than half maybe of that price. But with a little bit of labor, you can have a similar craft that is high performing at a pretty small fraction of the price.

Tim: Speaking of weekend, this isn’t your day job, is it?

Ben: No it is not. It is a side a small business along the side.

Tim: What’s your background and what do you do during daytime you work week?

Ben: So my background is in physics, I got my PhD in physics; I studied fluid dynamics so a lot of it really relates well working on props and engines is really exciting. So I work at an energy company during the day doing research.

Tim: Anything else people should know, if they want to find out more about this?

Ben: I am sorry

Tim: What would people need to know if they want to find out more about this?

Ben: Those who want to find out more, we try and keep our website pretty up to date, so it is www.lonestarhovercraft.com. So we’ve got several build logs that have complete start-to-finish construction pictures, we have a lot of work on engines, videos, things like that. So we try to make it a really useful resource for builders and people wanting to do their own craft. So that is the best source.

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