My Hovercraft Is Full of Eels
May 28, 2012 10:34 AM   Subscribe

Build a Hovercraft With Your Kids — When Jamie Hyneman and MeFi's Own™ Adam Savage built hovercrafts for Mythbusters, he realized that these floating-on-air vehicles were easy to make, not too expensive, and fun. So he built one with his kids. More diy hovercraft fun.
posted by netbros (47 comments total) 28 users marked this as a favorite
shit guys

hoverboards are here and they work on water
posted by LogicalDash at 10:49 AM on May 28, 2012

A coworker of mine made a hovercraft out of a leaf blower a few years ago. I couldn't stop imagining him poling it along the street like a hovercraft gondola. Which I don't think he actually did, but it's still a great image.
posted by rmd1023 at 10:50 AM on May 28, 2012 [1 favorite]

Forwarding this to my brother, who has two kids and a great joy for making their mother cringe. Should be fun! Thanks for the link!
posted by Mooski at 10:52 AM on May 28, 2012

I wish asavage was my dad.
posted by Cool Papa Bell at 10:54 AM on May 28, 2012 [3 favorites]

Sorry, but if you need to demonstrate your love for your kids by wasting a whole day building a hovercraft, assuming you can even find an unwary gardener who left his leaf blower in the back of his pickup while he runs into the coffee shop, you are trying way too hard.

Oh, and you know who has spare shower curtains just lying around waiting for a project? Serial murderers, that's who.

This whole thing is odd and overcompensating.
posted by Keith Talent at 11:01 AM on May 28, 2012 [3 favorites]

Hovercraft are fun, but there is a critical safety tip. In this sort, where you have no propulsive poer, flat surfaces are critical. You are on the closest thing to a frictionless surface you can make, and you will pick up speed rapidly on any grade.

If you have enough thrust and directional stability, you can handle grades. This won't.

The safety mechanism is the throttle. If you start to slide, pull back the throttle, which drops lift, and drag slows you down. Thus, the most important tip - you must have control of the lift engine.

No control + grade = some form of bad outcome, and how bad depends mostly on how much velocity gravity gave you before you hit something.
posted by eriko at 11:04 AM on May 28, 2012 [1 favorite]

One challenge in Junkyard Wars (AKA Scrapheap Challenge) was to build and race a hovercraft on a beach. One of them ended up blowing out its skirt and couldn't finish, but the other one worked really well.
posted by Chocolate Pickle at 11:09 AM on May 28, 2012 [1 favorite]

Sorry, but if you need to demonstrate your love for your kids by wasting a whole day building a hovercraft [...] you are trying way too hard.

Is there some version of this link I'm going to need to go look up in the Wayback Machine or something, because I'm not getting this. Much more annoying is the ten seconds of actual demonstration video bracketed by 60 seconds of ads that do involve an airline guilting working mothers into buying the Wi-Fi service so they can "be their real selves," which involves looking vaguely like Julianna Margolies and acting all nurturing over IM.

Now that I think of it, it does sort of suggest that the Wired ad server has a taxonomy node for "guilty parents."

Anyhow, in my neighborhood, you can harvest neglected leafblowers by the dozen: Everyone has moved on to pressure washers as the key signifier of seriousness about ones home. The only neighbor still using a leaf blower is the fellow with the bloodshot eyes who goes out into the street to stir up pollen at 7:30 a.m. Nobody with that savage a disregard for the sanctity of Saturday morning is going to extend any mercy to a would-be leafblower thief, so we'll avoid him in favor of easier pickings and probably still be able to use our whole Subaru in place of the lawn chair.
posted by mph at 11:29 AM on May 28, 2012

I too am angry about people doing fun things with their kids.
posted by middleclasstool at 11:45 AM on May 28, 2012 [33 favorites]

Wow, that is cool. What an awesome project for a family! But I think there should be encouragement to wear helmets and for the parent to try it out several times before letting the kids have a go.

Now where is my hover skateboard? Michael J Fox promised me one by now. Adam Savage, you're holding out on us.
posted by Chaussette and the Pussy Cats at 11:48 AM on May 28, 2012

Sorry, but if you need to demonstrate your love for your kids by wasting a whole day building a are trying way too hard.

I know you! You're the parents of all those people I used to work with who were utterly blown away that I could do amazing, superhuman things like cut threads in a piece of metal with a three dollar tap from the hardware store, or who needed me to explain to them how to fix their three way light switch or their washing machine drain or their garage door opener or how they could build this really awesome lamp they saw on the internet, aren't you?

In other news: Get in line guys!
posted by Kid Charlemagne at 11:56 AM on May 28, 2012 [5 favorites]

I remember making a working model of a hovercraft out of an old umbrella, plywood, some spare RC car motors, and a couple of RC plane props, with my dad, for a class project (one of the kids in the class thought all it was doing was inflating a balloon underneath, until it slid across the classroom floor). That was a lot of fun, but of course I couldn't ride it which would be super awesome.

I like his solution to keep the skirt from blowing out and deflating, very elegant.
posted by deliquescent at 12:01 PM on May 28, 2012

I got one commercial, 5 seconds of hovercraft, 2 seconds of another commercial before pulling out.
posted by uraniumwilly at 12:04 PM on May 28, 2012 [1 favorite]

I wish there was some sort of control mechanism included such as a blower with flaps, but I suppose that would (greatly?) increase complexity and expense.
posted by Phreesh at 12:06 PM on May 28, 2012

A second leaf blower rotating on a vertical axis and blowing parallel to the ground would give some controllable thrust, but again, the thrust would have to overcome the grade.
posted by Jesse Hughson at 12:14 PM on May 28, 2012

the thrust would have to overcome the grade

that's what she said
posted by found missing at 12:18 PM on May 28, 2012 [4 favorites]

I'm so building this.

All you need for directional thrust is a brushless model aircraft motor, LiPo batteries, and something to stop the prop from cutting you into small pieces.
posted by unSane at 12:53 PM on May 28, 2012

I have always wanted to make one of these things. (They're not really a new design by the way, there are a thousand variations on the plywood-and-leafblower hovercraft plan.) It's one of those projects that I've never quite had the time, space, and tools for. Someday, when I have a proper workshop or at least a garage or a back yard, I will make one for my kids. Ideally it will be steerable, and there will be two of them so they can have races.
posted by Scientist at 1:09 PM on May 28, 2012

Did he order the plans from an ad in the back of Boy's Life magazine?
posted by cosmic.osmo at 1:22 PM on May 28, 2012 [6 favorites]

Looks like fun, in a perfectly level parking lot.

The video sucks. 30 second ad, followed by 10 seconds of a guy drifting into the frame. wow.

Save the video guys, show me a drawing or photos of what you built.
posted by Marky at 2:50 PM on May 28, 2012

This kind of hovercraft would be perfect for street air hockey.
posted by Sys Rq at 3:36 PM on May 28, 2012 [1 favorite]

I want to build this under all the chairs around the pool and not tell anyone on the 4th of July, when I fire them all up at once. Wheee!
posted by xingcat at 3:58 PM on May 28, 2012 [4 favorites]

That's all well and fine; what I need to know is if the hovercrafts are full of eels. Oops, just caught the title, well played.
posted by Jaymzifer at 4:15 PM on May 28, 2012

I want to give this a try. I've wanted to build a hovercraft since I saw the aforementioned ads in Boy's Life.
posted by drezdn at 5:05 PM on May 28, 2012

The hovercraft in the back of Boy's Life taunted me as well, looking so perfectly plausible that I thought maybe someday I'd build one, along with a real laser gun and that air car that turned out to be about nine inches across when a foolish kid with a pliable parent placed the order and waited his six to eight weeks for...well, that's no fun at all.

Fortunately, despite the complete absence to this present day of a hovercraft in my life, my father was odd and overcompensating, too, though his madness lay in an altogether more electrical direction. He was the first person to point out that if you trudge down to the high tension pylons with a four-foot Deluxe Cool White fluorescent tube on the right sort of night, when the wires hiss and crackle overhead with more energy than you'll use in a lifetime, you can raise the tube overhead, give it a little wave, and see it flicker into a sort of magical half-life, connected to nothing at all.

Of course, my father had roots in radio, having worked his way up from the kid who changed the aircraft warning bulbs in the little AM radio station in Thomson, Georgia back in the early fifties to an occasional overnight DJ, slipping proper longhair music into the syrupy sea of gospel and Montovani, and had a ham shack in every home he had, including ours. He'd briefly been an occasional tympanist and pickup thereminist for the Birmingham orchestra while supporting himself as the consort of a wealthy older woman around town, working off thoroughly falsified credentials in the field and a natural musical bent, and when I started to go science-mad, he sat me down and walked me through the process of building a theremin, from hand-winding coils to getting the goddamn thing's drifty heterodyning to settle down.

He'd always talk about Tesla with a kind of distant reverence, and even then, Tesla was sort of the figure that existed like the minor characters in the Bible—full of miracles and not much corroboration. He'd already procured an enormous neon transformer that we used to build a Jacob's Ladder, as well as many of the more obscure parts for projects in the entirely intriguing book Things A Boy Can Do With Electricity, which was old enough that a number of the projects called for Model T parts and other technical debris of that era, so he was along for the ride all through my youthful obsessions.

I'd found another amazing book from before my time, Bob Brown's wonderful Science Treasures: Let's Repeat The Great Experiments (long, long out of print, alas), which laid out very specific plans for a simple Tesla coil of an older design that I understand is...erm...counter-indicated these days, largely because the author promoted, and illustrated with glorious black-and-white dreamscapes, putting a hand directly onto the top of the secondary coil so that you could do amazing things like raise a hand while wearing five modified thimbles and cast lightning into the air like anyone but an odd and not very popular kid.

We built one for the school's science fair, and it was one of those key moments in my life where my fussy, lazy, complaining instincts all went dead quiet in the face the possibility of throwing actual lightning bolts. My dad was dead set that everything to the project would be my own work, not one of those embarrassingly pristine daddy-built showpieces, and he made me draw up proper diagrams for each things, down to drilling me on the proper handwriting of a draftsman. The plan in the book was clear and precise, and we made few changes. Dad did decide that the coil needed a better safety enclosure than the dull black box Bob Brown suggested, and he did the plexiglas work because everything I did with plastics and glue ended up in tragedies with B-17G model kits looking half-crashed at completion with landing gear glued inadvertently into my hair.

My primary coil looked like hell because I was vibrant with impatience at that age, and the ball my father found to be the ball top of the secondary coil was a copper toilet float, something that mortified me until I realized that virtually no one in my age group have ever been curious enough to look into the toilet tank.

We fired it up in the 'shop, the building my father had constructed in the back yard out of wood he'd salvaged from a gas station being torn down on Fort Meade, and it was a monstrous, crackling, wonderful thing, like my Jacob's Ladder and yet existing on a whole other level. Dad flipped off the huge fluorescent fixture overhead, but it stayed lit as the spark gap in the coil sang the song of oxygen changing into ozone.

"Let's try to throw a lightning bolt," he said, with the kind of muted childhood glee that was hidden just below the surface, below his trappings of businessman, salesman, and parent. He switched off the coil, had me take the switch, and put a hairy paw on the toilet float while holding a nail jutting from a closed fist with the other. "Try it, but if I look like I'm gettin' electrocuted, turn it off again, okay?"

It took a moment to rally my nerves and convince myself that I was not going to electrocute my father because the book said it was perfectly safe, and I flipped the large switch in the base of the coil's cabinet.

My father did not die, and a two-inch arc played in the air from the tip of the nail.

It was magic of the best sort, because it was real.

When it was my turn, I put on the thimble I'd modified by soldering a needle to the side, put my hand gingerly on the toilet float, raised my hand with the thimble in a we're-number-one gesture, and nodded.

I hardly feel the electricity, but I could feel the world spinning on its axis.

The little spark crackled and darted through the chemical soup of the air in the room, and I was briefly the most fully realized human being that ever existed or ever would.

It's just a little spark after all, but that's all we are, and it is too easy to hide that.

"That was the best thing ever," I said, but I was already planning more and more ventures.

The neighbors hated the damn thing, of course, because the old-style spark gap at the core of the coil disrupted television throughout the whole neighborhood, and it would eventually bring about the first of the two visits I was to receive from the FCC before my brief and erratic career as a scientist would end.

At the science fair, though, I killed. It wasn't hard when every other kid showed up with a sad papier mache volcano that belched vile orange baking soda lava in what wasn't remotely a science experiment, so I went straight through to the big city science fair. I'd done some experimentation, too, but nothing really new, so I ended up getting an honorable mention for my craftsmanship and showmanship, despite the fact that I had caused a near-panic at the fair whilst demonstrating my lighting-throwing prowess. In mid-throw, I leaned against the wooden folding table, which had a fluted aluminum band in those days, and a substantial arc leapt through the crotch of my Toughskins to the metal band, which then zapped its way down the entire row of tables, shocking dozens of young scientists and the general public as well.

Still, I'd never won anything. I was featured in the local paper!

Doesn't sound like much, but I was the second most unpopular kid in Scaggsville, Maryland, and I came back to my school as a victor in the cause of showing the world exactly what kind of stuff we were made of at Hammond Middle School. Carted the Tesla coil back to school with me and I was asked to demonstrate for every science class. I was such a blowhard, even then, that during one demonstration, when I was screwing a lightbulb into a little apparatus I'd built to show the effects of high voltage on a lightbulb, I broke the bulb in my hand, cut myself to bloody ribbons, and just carried on anyway, with my medicine show flourishes throwing a spray of blood along with lightning.

I did not become a scientist. Turns out I'm not really smart enough, a fact that I'd reinforce later in my time at Explorer Post 1275, where actual smart kids did amazing things while I stood in the background because I didn't have a damn clue how to write code on a VAX 11/780.

My father backed me up in my gearhead pursuits, though, until I decided that only the Frenchest of French cars would do, and he'd look in the engine compartment of my Citroën and just scowl. The Tesla coil ended up dismantled, to better fit in the attic, then was raided for parts in what would bring on my second, and more serious, visit from the FCC, and eventually it was gone, except for the original neon transformer, which is sitting on the bookshelf about six feet west of where I am right now.

I did not become a scientist, but when my old career path faltered and my intended one proved to be completely disconnected from a means by which it could be used to produce something that could be exchanged for goods and services, I ended up finding out that the whole time I'd been sighing and rolling my eyes and impatiently trying to speed things up on the projects I did with my father, I'd actually been learning something, just like he said.

What I do now to pay my bills is nothing like science, but I've fallen into a field where the facility for understanding problems, conceiving solutions, and making things better serves me very, very well. In my next career, whatever that turns out to be, I suspect I'll do just fine, and if the bottom falls out of the economy, again, I know how to build stuff and fix stuff and make things, and there's always going to be a market for that.

My father died almost fifteen years ago and never really got the chance to see where that spark of playful inspiration would lead for me, except in the early form of my first big performance pieces, when I'd fire up the synthesizers on a dark stage, step up to a microphone, and do my level best to set the electricity free again. It just takes a few moments like this—of walking kids through the process of turning impossible magic into real things that can be done by real people—to make all the difference in the world.

Just think what we could do next.
posted by sonascope at 5:43 PM on May 28, 2012 [99 favorites]

I too am angry about people doing fun things with their kids.

Me, too.

(Eek. Some dads are a tad on the defensive/judgmental side when it comes to how other dad's should relate to their kids, it seems.)
posted by saulgoodman at 5:47 PM on May 28, 2012

sonascope: "It just takes a few moments like this—of walking kids through the process of turning impossible magic into real things that can be done by real people—to make all the difference in the world."

posted by Tchad at 6:07 PM on May 28, 2012

The conversation started like this:

"Hey Adam, wanna write an article for us about all the cool shit you do with your kids?"

"Umm, yeah, about that... The thing is I'm kinda not really the type of dad you imagine that I am. I don't do tons of cool projects with my kids. I should do more. I feel like an asshole, but I've only done like 4 or 5 craft days with them, like , ever. "

"Like what?"

Then I listed the three things that I could remember doing, they asked me to write them up, and I did.
Perception does not equal reality.

Sonascope, your post is why I love MeFi.
posted by asavage at 6:08 PM on May 28, 2012 [21 favorites]

My husband and I loved the hovercraft episode of mythbusters! The wired article is great, makes me hope when my baby is old enough we have a garage or workshop to build fun projects in.
posted by HMSSM at 6:11 PM on May 28, 2012

In an alternate universe where genies are real, Adam Savage's son Cool Papa Bell kicks himself for his lame wish while assembling yet another macramé pot holder.
posted by dr_dank at 6:18 PM on May 28, 2012

"Umm, yeah, about that... The thing is I'm kinda not really the type of dad you imagine that I am. I don't do tons of cool projects with my kids. I should do more. I feel like an asshole, but I've only done like 4 or 5 craft days with them, like , ever. "

The only asshole is the guy who doesn't wish he spent more time with his kids. Building a hovercraft goes a long way, asavage.
posted by Rock Steady at 6:21 PM on May 28, 2012 [1 favorite]

My hovercraft is full of....damn it!
posted by neuron at 6:37 PM on May 28, 2012

Are there anymore pictures of this thing? I saw the article a couple days ago and I'm unable to put the description to a plan of what goes where. Even a single picture of the underside would be most illuminating.
posted by Mitheral at 6:47 PM on May 28, 2012

I remain in awe of hovercraft ever since seeing them on Blue Peter as a child. Hat tip to Christopher Cockerell.
posted by arcticseal at 7:09 PM on May 28, 2012

One thing that wasn't immediately clear to me from the Wired article, asavage, if you're still around. I've got a small, fairly low-powered, electric leaf-blower. Would that potentially work for making one of these things or are there certain minimal blower engine specs to look for?
posted by saulgoodman at 8:24 PM on May 28, 2012

We built one about ten years ago for our son's science project, too. Used a shopvac, plywood circle with a folding chair bolted to the bottom, bicycle tire tube, and a piece of heavy plastic for the skirt. It worked GREAT, but was not the safest thing in the world. It went really fast. The kid was the hit of the seventh grade for a day.
posted by raisingsand at 8:47 PM on May 28, 2012

Thanks for sharing that, sonascope.
posted by Songdog at 8:54 PM on May 28, 2012

Holy crap, you mean leafblowers actually are good for something?
posted by louche mustachio at 12:48 AM on May 29, 2012 [1 favorite]

I wish sonascope was my dad!
posted by a humble nudibranch at 1:07 AM on May 29, 2012 [1 favorite]

Saulgoodman, I tried with an electric blower, but diidn't have enough oomph- couldn't get pff the ground.
posted by jenkinsEar at 5:38 AM on May 29, 2012

I'm doing a soapbox racer with my oldest right now - obviously I have to step up my game!
posted by Harald74 at 6:54 AM on May 29, 2012

Start simple. I had some time with my son and we made a bird house. A stupid, simple, craptacular birdhouse. He's 5, so he was able to help mark off the cuts, which I did. I let him drill the small holes (for the perch and holding on the bottom) and he was in hog heaven. See that smile? Yeah, that's the reward. He also liked putting the pencil behind his ear.

Keep it simple and in their interests. I went on a lunch date with my daughter and took a ton of photos because the light wasn't bad. We went to a drug store and she picked the ones that she thought her mom would like best and we put them into a frame that she chose.

Kites. If you live in a place that has good wind, make kites. You can knock one out in a half hour using wrapping paper, dowels, tape and string. And if you start down the road of larger kites, you can start doing photography from the kite. It is a good era to live in when cheap, decent photographic equipment is so portable. You can loft a few ounces of plastic and batteries and capture a half hour of video for about $30. That is effing amazing.
posted by plinth at 7:17 AM on May 29, 2012 [4 favorites]

Saulgoodman, I tried with an electric blower, but diidn't have enough oomph- couldn't get pff the ground.

That's what I figured--mine doesn't seem to have anywhere near enough thrust for something like this. I guess I could try to run the numbers myself, but I was hoping for a pro-tip...
posted by saulgoodman at 8:32 AM on May 29, 2012

When my son was about 9 yrs old he made a hovercraft at Science Camp out of a CD, a pop top from a water bottle, a balloon and some duct tape. It floated all over our dining room table and impressed the heck out of me.
posted by ThatCanadianGirl at 8:52 AM on May 29, 2012 [1 favorite]

ThatCanadianGirl, do you have any more details? Or a picture or sketch? I know some Cub Scouts who would really dig that.....
posted by wenestvedt at 1:13 PM on May 30, 2012

Oh, good heavens, I was obviously overthinking it!
posted by wenestvedt at 1:14 PM on May 30, 2012

Yep, wenestvedt, that's pretty much the one!
posted by ThatCanadianGirl at 6:23 PM on May 30, 2012

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