Picture of 10 HP Hovercraft
I was looking for a project that my Grandson and I could build. together. We decided on a hovercraft after watching a TV special. Knowing absolutely nothing about hovercraft we researched the web on the subject  and found the Universal Hovercraft website to be the best source.
We had an old 10 HP Briggs horizontal shaft electric start engine from an old riding mower that looked like it would fit the bill.  We bought the plans for their UH10F craft. We liked it because it only uses one motor. Most hovercraft use a separate motor for lift and thrust. This one directs approximately 1/3 of the thrust air to provide both lift and inflating the skirt. Most of the materials could be found at the local builders supply.
The only parts we needed to buy from Universal Hovercraft were the Plans, propeller, propeller hub, and the skirt material. Although it busted our $500 budget we decided to purchase their materials kit which included all the epoxy,fiberglass , screws, and glue. The skirt is the heart of this thing and we didn't want to save penny's  on something this critical. It was a fun project for the both of us. It would be a great Father and Son project.
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fortneja3 years ago
I built a UH-10F myself back in high school. I was slowly putting together an instructable for it several years ago, but it was taking too long, so I gave up. I can send you my notes and photos if you want to elaborate on some of the steps.

I originally used the rope and pulley system specified in the plans for steering, but later modified the steering to use bicycle cable, which was much more durable and responsive.


I am trying to build an UH-10f.

it would be of great help if you could give me those notes which you prepared.

yhank you.

please get back to me at

Dear Fortneja, I just saw your post and wondered if I may take a look at your notes and photos for the UH 10F? I am about to build one and would grately appreciate
Thank you,
Dan Farncombe:
Very cool! How Much does it weigh?
mickydee (author)  hover_crafter3 years ago
I am not absolutely sure. I would guess about 125 lbs., maybe 150.. The engine and prop are the determining factor. The bulk of the craft is made of very light weight foam and 1/8" plywood. If you go to larger motor with electric start, you could double up on the foam quite easily.
Thats alot
Its awesome
Wow! Intresting
Jackylee2 months ago
Nice . I'm Vietnamese
Please sent me plans , I don't understand under the boat work . Thanks
Jackylee Jackylee2 months ago
Please share me plans thank you !
bdubu3 months ago

Great instructable Roland! Thanks for sharing! BTW, judging from your bio, I suspect you'd be right at home at the wheel of Rudy Heeman's hovercraft (

bbfly5 months ago

I have the plans for this hovercraft. Your assembly steps will make it easier for me to put it together. Thank you very much

ninjabatman6 months ago

this is super awsome

mickydeejr6 months ago

this is boss

coolboy1011 year ago
Hi there, I know this instructable is getting quite old now, but I am thinking of building a hovercraft as a school project, and this one seems relatively simple and your guide is really helpful! Unfortunately, being in the UK I cannot get the plans to this hovercraft easily or buy any of the kits, so would like to ask a few questions if that's ok.

1... How large were the pieces of plywood? The hovercraft is 10ft x 5ft and I can only find 8ft x 4ft plywood. Did you have to join more than one piece together? If so how did you do that?

2.... What parts of the hovercraft were actually fiberglassed? Not the whole thing presumably, just the joints?

3.... Is any type of foam acceptable? I have found some 50mm (2") Styrodur which is "extruded rigid polystyrene foam (XPS)" with a compressive strength of 300 Kn/m². Would this be acceptable do you think?

4... How powerful should the engine be? I have found a brand new 13hp engine for a good price. Would this be a good size or will it be overkill or too heavy?

Any help would be much appreciated! I am sure I will find many more questions needing answers, so if you could help that would be great.

Thank you!
SofiaM1 year ago
How big is this hovercraft? 4 by 8, or 5 by 10? Thank you
mickydee (author)  SofiaM1 year ago
The hovercraft is 5 x 10 overall. I bought it at a local builders supply in 4 x 8 sheets.. After it is covered with the 1x4 plywood and fiber glass the joints are all covered. Alternate the joints between the foam and plywood for strength.
SofiaM1 year ago
How big should the sheet of 1" styrofoam be? Thank you!
BoSkarr1 year ago
This is amazing. I plan to start one that want to hald more than one person. This is a great guide, as I can't become a member of universal hovercrafts because I am 14, don't have a job, and I don't have a phone. I have a couple friends who will help and I can't stress it enough how amazing your hovercraft looks.
you should enter the epilog challenge V if you can
shull32 years ago
Congratulations on a successful first build.
This is a great project for Father/Grandfather and Son/Grandson. Universal Hovercraft is a great company for DIY hovercraft projects. I build a UH12T4 with my high school soon back in 2002 -2006. We have had a great time with it and now belong to the Hoverclubofamerica. The club has great resources for recreational hovercrafting throughout the USA. Most of the members have either built or operate a homebuilt hovercraft. If you and your Grandson get into this hovering more be sure to check out the HCA. We sponsor over 20 events a year at many locations around the country.  Here is a map of the locations for the 2013 season. Hope to see you at out hovering this year!

Scott Hull

I was wondering if I could use any type of epoxy or is there a certain type that would work a lot better? What would you recommend.
mickydee (author)  phynicfirebird4 years ago
I always use the cheapest I can find. Tru to use something that is easy to mix, like a 2 to 1 or a 3 to 1 ratio. Any epoxy you can get will work. You will need about a gallon.
Mr. Dee, I'm stoked. I'm in the third world and this is the thing to have.
I can get most parts here
Can you tell me a ratio to increase the size to accommodate 2 people or 180 more pounds
Thank you....i am hoping to build my own from scratch this summer without any kits...the only problem i have is that since i am only 16 and do not currently have a job (wish i did) it is going to be hard to get the money but i am hoping to get a job real soon then start saving for the parts.
council cleanup days is your answer
gear7622 years ago
Your project is pretty sweet! I plan on building a hovercraft for a science fair at my school, but as of yet, no one has any description of how to put on the skirt or what size/how many holes to cut out for a 4ft by 8ft hovercraft. If you could maybe send me a few pictures of the skirt, as well as some basic instructions on how to put the skirt on and cut out the holes, that would be great! Thanks!
Xthinker2 years ago
I cant seem to find the website, can you post a link to it? I'm interested in making one
dirt_hawker2 years ago
How much do you and your grandson weigh? How would you describe the diffrence in weight and perfermance?
vlxwgn4 years ago
Do you have any more information on the skirt installation? Did the skirt you bought come with instructions? Other than that awesome :)
mickydee (author)  vlxwgn4 years ago
Yes the kit come with very good instructions on cutting and installing the skirt
I was lucky, Grandma is a seamstress and added her touches to it. Don't let that stop you
mrtomc mickydee2 years ago
I have a UH-10f that I purchased already built. It was never used. I had to fabricate a rudder stick and add a throttle cable. Both work great. I had it on the lake yesterday and it got 19 mph on the gps. The only trouble i have is that I get water in the skirt inflation hole and I have to drag it up on shore to drain it. There is a slit in the bag in the right rear that i used to drain the water. Should i make some ductwork to raise the intake hole to keep water out?
mickydee (author)  mrtomc2 years ago
I did not have that problem. Your center of gravity may be more to the rear than mine. Adding a riser around the port should fix your problem.
have fun
mickydee (author)  vlxwgn4 years ago
Good idea I don't think they had that one when I bought my plans
Does the skirt inflate when you start it or it stays inflated? Looks like fun!
mickydee (author)  bnsfwarbonnet2 years ago
A portion of the prop air is diverted to the skirt port and inflates when the engine is started. The craft wont sink when the engine is off because the deck is made of enough foam to keep it buoyant
It is a lot of fun Mickydee .
cod3hack3r2 years ago
When i grow up and have kids and hopefully grandkids, i hope i can do something like this with them, this is such a cool project, wonderful instructions too, and it came out great. This is great man, 10/10
mickydee (author)  cod3hack3r2 years ago
Thank you very much.
My grandson and I had a great summer working together.
We really got to know each other.
We both learned some new skills. That's what these instructables are all about.

serice3 years ago
When type of epoxy die you use to coat the bottom of the hull with?
mickydee (author)  serice3 years ago
I used an epoxy called "System Three" medium temp. I bought a gallon on line, It is available from several sites. I liked it because it comes with attached plungers for accurate measuring and it cures overnight. Be sure to use the vacuum bagging procedure as spelled pout in my ible. You can use just about any two part epoxy you want, it is not critical. I used half a gallon for the whole project
i rember the first one i built, aha that was a awsome day i spent a whole week with my uncle sketching and looking at the gaint hover crafts called LCAC-landing craft, air cushioned”" used by the marines and they are amphibious by the way
Mr. walrus3 years ago
What kind of trailer did you use?
mickydee (author)  Mr. walrus3 years ago
My trailer is a 4 by 8 with removable side rails. It also has a dump feature with a pin in the front. I can literally drive it off the trailer, but it will not climb the incline by itself.
Two people can easily lift it onto the trailer. It could be easily winched on if the motor was left idling to provide a little lift.
WOW I wish my grandpa was this cool
yeah right???
arjun05203 years ago
dude where did u u get the motor from
Wahoo963 years ago
hey, im thinking of making my own,what engine (make/model) would you recomend??
Wahoo963 years ago
is it amphibious? how fast is it? and can you put a more powerful engine on it?
tdem3 years ago
Just a little warning. Not long ago, a man here in NZ was decapitated by his kit built hovercraft. Be careful!
voyageur10 tdem3 years ago
Don't leave us hanging! What happened exactly?
deobomb3 years ago
do you think it would work if i used a large inner tube and a small 110 atv motor to make a small one
ctz3 years ago
I was wondering if you could tell me the time it took you to build this amazing contraption.
avatar_i3 years ago
Forgive me if I missed this, and I am quite bad at math, but: How far and/or how long can you run this beauty on a gallon of gas? If you were to estimate the gallons per mile- as it were- what do you think it might come out to? My thinking here is to build one for one human and two 30~50 pound Dogs to
be traveling about.
Looks liks a blast to ride in, too! I only hope I can succcesfully built it!
Quite entertaining and instructive, and one of my top ten favourites!
They aren't quiet, it would most likely scare the poop out of your dogs.
i dont know about your mileage for one gallon but i can tell you if you weigh oh say 130 then you will probably need a separate engine for the skirt so it can lift you and your dogs at the same time
rocketman203 years ago
So that small rectangular hole fills the skirt and the big hole goes straight to the inside of the skirt which creates pressure and causes lift. That makes so much more since. Do you know the dimensions of the two holes.
cpeterkelly4 years ago
The only thing I've seen go 'very wrong' with one of these craft is if you take off your T-shirt because it's wet, or you're hot, or you think the photos will be better as a result. Then the next time you throttle up, the shirt becomes airborne, is sucked into the intake and causes your highRPM propeller blades to EXPLODE.

Or at least that's what I remember it seeming like. Eye protection on a hovercraft, even though the blades are behind you, is a good idea.
Usually these have a steel mesh screen on BOTH sides of the prop so that that never happens. I have seen lots without that safety feature and I assume that after 1 arm/limb is lost (Maybe 2+ in the case of extreme cases of stupidity/drunkenness) that it is fixed immediately.
The one I saw explode had a mesh screen - the fabric seemed as 'smoke' as it passed into the blades.
You mean steel fabric. The mesh I am talking about is the stuff made of pencil thick steel rods welded together about 1 inch apart. Like the stuff shopping carts are made of. but the most recent reminder of folks not taking safety as seriously as they should.
This is his "organized" shop. Its a single car garage, and by organized, I mean he didn't have tools piled 8 feet high like the 4 other buildings, which are all, DOUBLE garages. He taught me everything I know about any trade.

Again, he would still work here if safety was observed closer. I am probably rambling, sorry, ever sense it occurred I can't stop talking.
Yes, and unfortunately on July 26th this year we had an accident on my grandparents farm which could have been prevented by observing safety more closely. I was helping my grandpa put up barb wire fence and we had finished, I was closing a gate while he went to wash off the quad and trailer and it rolled on its side just behind the Quonset hut. Me and my grandma were the only ones there and the Ambulance took too long and he bled to death on the lawn. He was always a bit rammy around equipment and only ever wore a hard hat which doesn't fasten to your head. He loved working and tinkering though, and died doing what he loved I guess. If he had slowed down a bit and wore more appropriate safety gear it could have been avoided.

It is amazing how fast an accident can happen though there was only seconds that past.

Now we have his 8 (greedy) kids that want all of his tools to sell for money. My Grandma said I could take some, and I much rather have them and use them then let those greedy kids have them. The first thing they ask about is his bank account. I don't think they will ever get around to taking his tools. He has 5 buildings full of tools, and only one is organized. The amount is astounding. And even though it is organized, I am the only person that knows where a specific item is in it because I have been around him so long. I loved spending time with him.

It still feels unreal.

It goes to show, safety should be observed, if its not, things can go wrong so fast, its unbelievable...
mickydee (author)  Wesley6664 years ago
We were aware of the safety hazard. and before we took it to the lake we installed a wire mesh screen on the intake side of the prop. It may not show in the picture but it is there
I would definitely suggest putting something on the back as well. I know someone who is missing pieces of his right arm and hand due to an accident with a prop, not a hovercraft prop, but none the less, the more you can cut off of possible outside contact the better, and this can be completely closed in. Its a suggestion, but not necessary.
flarsson3 years ago
I'd install a fan guard of somekind, wouldn't be too nice to get something driven trough my neck. Anyways great project :)
wht not put a larger motor/prop and get more lift and speed? I guess it would work...I may try this
MAKE A VIDEO!!!!!!!!!!!!!!!!!!!!!!!!!!
gellis13 years ago
hello, i am about 15 and wanted to build a hovercraft with my friend and this looks awesome, but I am only a beginner DIYer so I don't have much experience, also do not have an engine and we are both a little strapped for cash (the 500$ budget is totally do-able but i wasn't sure if that included the engine or not). would this still be possible for us to build! also does it work well on land? (thats another must for us!) but great project anyway! thanks!
SIRJAMES093 years ago
I have windows vista os & I had no sound either, so I doubt that it is anything to do with your MAC. It has to be an Instructables malfunction or something....

Now about the boat.
I love it! I can see me building this but rigging it up for fishing all day! 8=D
It looks like it was a blast to play in!

TY for sharing!
SIRJAMES093 years ago
I'm droolin' over your workshop....wish I had one like that.
nibbler1253 years ago
I have been building basicly the same hovercraft. The only exception is mine has a seprate lift and thrust engine. One of my dads friends built one and later modified it to have twin engines. he said the speed wasnt increased much but its allot easyer to move around. I havent mounted my thrust engine yet but I just did my first lift test with great sucess. At half throttle I could easly be pushed around the yard whyle sitting in the craft. Or gain speed going down a hill
rocketman203 years ago
Do you know how many holes and how big they are on the inside of the skirt.
mickydee (author)  rocketman203 years ago
I don't know what you mean by holes! There are no holes in the skirt exept for the screw holes to hold the skirt to the wooden strips. The total screws are around 200 with about 75 on the inside and 100 or so on the outside. I didn't have any problems with the skirt tearing or coming loose. .The skirt inflated at just above idle and the craft lifted up about 3 to 4 inchs. I hope this answers your question
mickeydee, rocketman20 is talking about another common design for hovercrafts. Instead of having a hole in the base for air to be pumped into and then a second hole for air to go into the skirt, there is just one hole to fill up the skirt. The skirt then has numerous smaller holes around the perimeter facing in to pump air out of the skirt and underneath the craft therefore providing the necessary lift.
husamwadi3 years ago
what was the maximum speed
MRHint3 years ago
sdobbie4 years ago
It would be better if it was powered by lithium polymer batteries and a big brushless motor.
mickydee (author)  sdobbie4 years ago
We planned this to be a low budget project. Batteries , controller, and a motor would be cost prohibitive.
Fossil fuel powered internal combustion engines are environmentally prohibitive. Unless you power them with bio diesel or hydrogen gas.
Galt sdobbie4 years ago
Honestly...this is the sort of poorly thought out statement that I find offensive and beyond the pall of "being nice". Suggesting that someone replace one environmental negative with a greater negative is both irresponsible and just plain...uh, what's the word...significantly less than intelligent.

Costs and hazards of processing hydrogen into usable fuel, the entire ethanol tax payer funded lie and the environmental damage that making it does, the lack of real competitive energy per any unit of measure known between lack luster biocrap and petroleum, you just repeat this stuff 'cuz you saw it on the tellie? The media making something a 'Green' darling usually just means that one of their owners has an interest in the company getting grants of our dough to make them richer.

Mickey, awesome build, and thanks for the wonderful Instructable. I'm kicking around a couple of similar kinds of projects for this summer with my son. If I can figure out a way to concentrate the radioactive isotopes from our aquifer and now dairy products ( that our President told us weren't a problem and couldn't possibly endanger us), maybe we could make a glow in the dark one that ran on gamma rays.

sdobbie, you are right about one thing. Eventually the dollar cost of building wind turbines and solar arrays will out produce their initial investment, but not necessarily the environmental impact of their manufacturing. The other issue that promises to make spending dollars today a good idea is simply that as the Federal Reserve continues to crank trillions into the money supply the increased prices (it's been inflation in the past but now because we have Obama it's ...well just don't call it inflation) that we pay will continue out of control. The effect of increasing the money supply by %6 and then pointing to the stock market gains of %5 and calling it a positive move toward recovery is actually dumber than hydrogen fuel. BTW...not against keeping the planet from becoming a toxic landfill, but look at the people getting rich off of steering sheeple into these 'Green' cul-de-sacs of idiocy. Hydrogen is getting a big push to avoid committing to the already available and totally viable electric car. How else is Exxon and GM supposed to make money? When "The Terminator" and George Bush are doing public relations special appearances to roll out something as stupid as hydrogen fuel, everyone should be grabbing their wallets and covering their bums, 'cuz something really really bad is already in the works.

Mickey you can kill my share of the ozone layer with your irresponsible environmental nightmare. I don't care if you and your grandson are worse than B.P., I like what you guys built together. ; )

mmeadway Galt4 years ago
Galt; You hit the nail on the head, especially the part about money supply. As someone professionally interested in biofuels, I have to agree with your assessment of hydrogen as well -- it's not practical. Besides which, we already have a very handy way of transporting usable hydrogen called "methane", and there are ways of cracking the methane to produce residual carbon and free hydrogen -- but not in a production mobile platform. Still, burning methane (natural gas) for vehicles is actually very practical and is far less polluting than gasoline. It's a good intermediate step, and there's a lot of natural gas handy domestically. All that said, let's assume that sdobbie is being serious (I'm struggling with that) and look at the alternatives for hobby projects.

My $0.02:

For a real-world example, let's use the Hyundai Sonata Hybrid. This uses a 5.3 amp-hour, 270-volt battery pack that weighs about 96 lbs and costs about $10,000. This battery can supply about 1.4 kilowatt-hours (5.3 amp-hours times 270 volts) of energy (very approximate), or roughly 5 MJ (megajoules) before discharging (3.6 MJ per Kwh). Going back to energy densities, that means the battery pack is worth about 411 grams of gasoline (assuming gasoline is converted at 25% efficiency, or 12.5 MJ per Kg). At about 3.2 Kg per gallon, that means it's about 0.128 gallons of gasoline on a full charge. Gasoline therefore provides close to ten times the energy density of the batteries even at low efficiency, at a very small fraction of the cost.

The inevitable question comes up, which is "why can these cars go so far on the batteries with such small batteries?", and the answer is that you don't need all 40 HP provided by the Sonata's electric motor all the time. Usually, you need a fraction of it so the demand on the battery is lower. There's a huge difference in the horsepower required to maintain 30 MPH versus 60 MPH. Incidentally, it's interesting to note that the Volkswagen bug had a 36 HP engine, got nearly 30 MPG and topped out at about 60 MPH. The Hyundai Sonata Hybrid has a 40 HP electric motor. Hmmm.

When you do the math, you can see the problems. This is why I get upset with people who airily suggest that we switch to electric vehicles, and that the costs can be scaled with mass-production techniques. It does not work; the physics are against you to begin with. You can't put enough batteries at a low enough cost into a vehicle to make it work. You need at least five times the energy density we can now achieve, and even the upcoming nanowire batteries are only about double the density of the best batteries currently made.  We can also get into arguments about wind power, but given the usable capacity versus the nameplate capacity and the unpredictable power outputs, wind power is just not going to replace base-load sources.  Solar is far better, but very expensive ($8 per watt of capacity, installed cost).

So, for sdobbie to suggest lithium polymer batteries is fine, but cost and lack of energy density (not to mention some very real explosion hazards which have prompted warnings in the R/C model industry) make them impractical for mid-scale power requirements, like small horsepower motors on project vehicles. If you're really worried about the environment, use methanol or ethanol after retrofitting your small engine. Of course, now you have to worry about aldehydes in the exhaust, but that's another story :-) Natural gas would work, but there are some very strict regulations on how tanks can be mounted due to the pressures involved (3,000 PSI or more) and the safety requirements.

Thought I'd at least attempt a practical observation or two...

Its just so sad that environmentally friendly solutions are just so impractical.
I respectfully suggest that there is an error in your suppositions.

In the long term, environmentally-friendly methods are very practical. However, you are talking about changing the distribution of work and the energy conversion points, and retrofitting existing engine technology to work with different methods of energy transport.   All of that takes time, money and engineering, and there has to be a market incentive to make it happen.  Methanol, for example, is a very easy fuel to make using several methods (including catalytic reactions with steam and carbon), and it could replace gasoline so long as we are willing to modify existing engines and fuel systems. The biggest problem is infrastructure; you cannot just pump methanol down a pipe that used to be used for gasoline; the seals, pumps and valves have to be modified. Mathanol is just one of the possible solutions though. Just as solar power is another for baseload power, if you can figure out a way to economically operate when it's dark or cloudy. A lot of people believe that nuclear is a horrible thing, but there are other reactor designs and nuclear fuels that do not pose the dangers of uranium; these have not been pursued for thirty years, and perhaps now it makes sense to do so. Take a look at using thorium instead of uranium as an

I think we need to concentrate on solutions that require only incremental technological changes, not wholesale changes to as-yet unavailable technologies. Hydrogen is an enormous change; a cleaner liquid fuel is much more viable. So, I'm optimistic about environmentally safe power (both electrical and vehicular), but I get a little irritated when a solution is promoted without thought to costs, consequences or infrastructure. That's why I don't like batteries -- all technical reasons aside, most batteries contain large amounts of toxic chemicals and require a lot of energy to make (and the industrial waste produced is terrible). Something like an alcohol-based fuel would be far preferable, and its costs would be affordable even for the hobbyist. But, there are other possibilities too; butanol, esterfied vegetable oils (so-called "biodiesel"), and so on. What we need is for one of these alternatives to become economically and technically viable given our current infrastructure. Remember, you've probably got twenty years of changeover in the works once something is settled on. It will take that long for much of the existing fleet to wear out and get replaced by newer vehicles using the new fuels.

Here's a thought: Why not do a project to convert a four-cycle lawnmower engine to the use of methanol or ethanol, and publish the results here? Include a way to handle the aldehydes in the output (ethanol-based engines produce different types of pollution than hydrocarbon-based engines).  This is a far better way to go about things, and I think it would be informative for everyone here. Remember, many modern products and technologies started as a backyard idea that someone messed with for a long time before it became viable. Even the bicycle was a tinkerer's project before it became the number one form of individual transportation. In short, if you have a PRACTICAL solution that you can demonstrate, it's worth investigating and duplicating.
I can see where you are coming from there. But i have never seen an electric or alcohol powered car in my life. They are working on nuclear fusion in France i think but I am not sure if that one would ever work. To be honest this whole discussion has came about because I absolutely despise fossil fuels. The hovercraft is very cleverly made though.
U MEAN TO SAY U NEVER SAW ANY RACE CARS? Like alcohol dragsters?
Fusion is a long-term solution that is at least ten years if not twenty years down the road.  It's a worthwhile goal, but there are some major headaches to solve (like neutron flux) aside from the general confinement and temperature issues.  I'm sure it will eventually happen, but we need solutions for the short term.

Alchohol powered cars are used for the Indy 500, as an example.  These are fueled by methanol, which permits extremely high compression ratios and therefore more power per cubic inch.  The other advantage is that methanol fires are water-extinguishable.  In fact, aside from the problem that methanol causes nerve damage if ingested, it's one of the safer fuels out there.  Ethanol of course is also relatively safe (lower nerve toxicity), but more difficult to make in bulk, and ethanol production competes with food production.

My suggestion is that if you despise fossil fuels, start working on a solution!  I got interested in alternative fuels because I'd like to see the U.S. obtain energy independence, a goal that I think is very achievable.  I may not be the guy that makes it happen, but I can at least contribute something to the effort.  And again, it is usually the hobbyist that comes up with the first implementation of something that is practical and inexpensive, albeit unrefined.

Here's a thought for you:  All of us, tinkerers or simply commuters, have to deal now with $4 per gallon gasoline, and likely $5 per gallon by the end of the year.  If methanol (for example) can be used at a lower price, what would be required to convert a small engine to use it?  If that is a reasonable project to pursue, I'd say go for it.  If it can be presented as a way to reduce the cost of operating things like this hovercraft, then so much the better.  Methanol is available for about $3.30 per gallon in 55-gallon drums; that's cheaper than even discount unleaded here in Texas ($3.65 per gallon), and far less expensive than diesel ($3.90).

It would be a shame to build something like a hovercraft or a boat (or anything else that requires an I/C engine) and not be able to use it except once in a while because the fuel costs are so high.  Perhaps all of us collectively can come up with ways around that, while promoting environmentally positive technologies.  As I said before, there has to be a market incentive.  With petroleum climbing out of sight, perhaps now is the time.
Cubie2 mmeadway4 years ago
my main concern about using natural resources is if we use our food for car fuel what about eating it? And even if the food is unfit for US to eat what about food for livestock? World hunger has drastically increased since the common use of "eco friendly" fuel.
Yeah, it's eco friendly. But isn't the whole point of eco friendly to keep the earth in good shape and thereby keep us around longer? This is not a people friendly solution- not an eco friendly solution.
Don't get me wrong, I appreciate the people working on less environmentally taxing fuel- I just think there's a better way.
I can see that we will eventually have to try something else because fossil fuels will eventually become too expensive for most of us to afford. Petrol in scotland is around £1.30 per litre now. So we are either all going to have to get on our bikes or get the horses and carts out if this continues without a solution for everyone.
I like your comments. I would be interested to know what you know or think about fuels cells which are supposed to be more efficient and lighter than other batteries. i.e. lead cell. I am asking as I am truly ignorant in this area.
I'm glad you like the comments; I'm by no means an expert on all of this stuff and there are a lot of smarter people than I working on these things. My interest is practical; I think we need to get away from imported energy sources which means that there's a wide variety of stuff we need to implement, and I've started a business to work on conversion of biomass (cellulose) to gasoline, diesel and methanol using catalytic reactions. There's a lot of work to do, but I think we can achieve energy independence without forcing our entire vehicle fleet to retool, or having to throw out our appliances and start over. We also need the boost to the economy that a domestic energy production industry would provide.

Fuel cells have a lot of promise, but the difficulty is the fuel; hydrogen is the preferred fuel with all the problems that go with it. Fuel cells themselves are very efficient and trouble free, it's the reactants (oxygen and hydrogen) that are the hard part. In order to run a fuel cell on methanol, for example, you need a "cracker" to extract the hydrogen from methanol (methanol crackers are the cheapest and easiest), and an air compressor (atmospheric oxygen partial pressure is too low for direct usage). This reduces efficiency, decreases reliability and makes it expensive. That primarily is why fuel cells haven't really caught on. There's a lot of infrastructure "glue" that's needed.

There is research on better crackers, but so far nothing really practical has emerged. Hydrogen has a LOT of energy per kg -- 108 megajoules vs. 47 for gasoline -- but it is really hard to store and transport. It has a tendency to leak through metals, and of course it is highly flammable. It has a nasty tendency to autoignite when combined with air and exposed to sunlight. It also has an invisible flame (well, it emits ultraviolet), which makes it difficult to work with. Concentrations of 4% to 74% in air are explosive, which is an extremely wide range; by contrast, natural gas is explosive at concentrations of 5% to 15%. So it's not easy to handle and it can be extremely dangerous. I do not like the idea of hydrogen tanks on the road.

In the meantime, car companies are producing fuel cell vehicles, but you have to have a source of hydrogen for them to run on. Honda has a decent fuel cell vehicle, available only in southern California because that's the only place there are practical hydrogen service stations. Hydrogen is stored at 5,000 PSI (wow), and regenerative braking with a battery pack is used to recapture energy and extend the vehicle range (about 240 miles on a tank of hydrogen). It uses a 100 KW fuel cell stack, which is fairly large; that's 10 times the size you'd need for a typical house. Interesting technology, and Honda has done a very nice job on the vehicle. Honda also sells natural-gas powered vehicles, so they have taken a lot of initiative in the market -- my hat is off to them for that.

There's some talk of using electrolyzers and hydrogen storage at wind farms to store wind energy for later use, with fuel cells used to convert the hydrogen and oxygen. The overall efficiency is supposed to be about 50 percent. There's been research, but there are some major safety issues, since large quantities of hydrogen and oxygen stored in close proximity has a disconcerting property of going "boom" at the wrong times.

There are very small fuel cells available to power laptops and cell phones, that use mini-bottles (like the mini butane torch bottles) or cartridges for the oxygen and hydrogen. There's not enough hydrogen to cause problems, and the power output doesn't have to be high. The cost is high though.

Last but not least, there is a real push for "community" fuel cells that would power a few dozen homes. You can also get a fuel cell that will power a house using natural gas (a cracker is used to separate the hydrogen and oxygen from methane). Carbon buildup in the cracker is the primary maintenance issue, and the membranes in the cells have to be replaced after a number of years. These are very promising units, and I would expect them to do well as remote power units once the cost comes down. Here in Texas farm country, they would be perfect for running oil wells or remote households (an oil well needs a 30 KW power supply for the pump motor, and your electric bill can exceed $3,000 per month). Natural gas would be the fuel, and that is easily transported and stored (LNG or compressed). So, there's interest and a market -- cost is the problem.

Hope this is useful information :-)

I apologize to everyone for the lengthy comments....I kinda get going on this stuff :-)
Thank you for your swift response. You say you are not an expert but I loved the wealth of information you have given me. What is your field of endeavour? How did you come by all this information?
mickydee (author)  Galt4 years ago
I am overwhelmed by all the comments that have arisen over my little project using a fossil fuel engine. In all honesty my craft probably won't use as much gas as the average lawn mower will use in one month. I try to answer most of the comments directed to me, but I am going to stay away from these types of subjects. Since the average tinkerer doesn't have access to other types of propulsion at this time I think I will just muddle around will what I can get. Someday when the battery technology improves I would love to move into electric cars and such. They are just now offering airplane kits that are electric powered. I think you gave us a compliment but I am not quite sure.
Regards mickydee
It is ridiculous.

I believe that anything that is considered a "toy" doesn't need to be efficient, as it's a luxury and whatever amount you want to spend on it is your choice, and however responsible you want to be with the environment is your own choice too.
Go hug dirt if you want and live the lie its a semi-free country for now.
But get a life and let a father enjoy doing something with his son. That alone makes it very worth while. and Until Obama the First drives around in a prius and ditches Air FOrce One for Commercial. Dont expect everyone to get caught up in your zeal. Petroleum and coal used to be green.
They were never green because they produce GREENHOUSE GASES which KILL the OZONE LAYER! So, you get a life. Nice hovercraft by the way.
another brainless koolaid drinker try researching a bit for yuorself and see that the ozone layer naturally thins in cycles based on solar activity GLOBAL WARMING DOES NOT EXIST
Why'd you reply to my comment?

Accident, I hope.

There is no such thing as a "free country", but it is what it is.

I never said anything about this being bad. I meant it's ridiculous the people saying it is.

Re-read my comment.
sdobbie Bartboy4 years ago
I did not reply to any comment.
Bartboy sdobbie4 years ago
Yes, you replied to "Amaineman57"'s comment.

sdobbie Bartboy4 years ago
I can not see that anywhere on this page.
Bartboy sdobbie4 years ago
Either your computer is glitched, or you don't understand how the website works.
Screen shot 2011-04-18 at 4.49.12 PM.png
sdobbie Bartboy4 years ago
Oh, i see now. I thought that you were addressing me there. I am only new to the site so did not fully understand the commenting system.
Bartboy sdobbie4 years ago
I figured :P
do you get the staircase design now?
If two comments are lined up with each other, they're replying to the same thing. So if they're all the way to the left, they're replying to the instructable.
grt57 mickydee4 years ago
Keep on keepin' on Mano! Great project, thanks for sharing your experience and expertise.


Galt mickydee4 years ago
T'was that. Sorry for the diatribe. Something of a conditioned reflex to evidence that the money handlers propaganda machine is so effective at promoting their next fiasco at our expense. The image of Arnold driving up to open Cali's newest hydrogen station in a million dollar H powered Hummer, and 'W' stumbling and bumbling around to come up with something as profound as "this hydrogen stuff is good" just sets me off on the rant path. Proponents of ethanol have the same effect.

As to hovercraft not having a very practical use, I beg to differ. They are tough to beat for amphibious landings, should you have any plans to invade a neighboring land, and they do make a dandy means of rescue on a variety of surfaces that are inhospitable to traditional water craft. Other than that they just look like they'd be a blast to run around in. Great job Mickey! In the end, the shared process and the resultant fun that you and your grandson will enjoy are I'm sure priceless.
It was not really a complement or insult. It was more food for thought really.
sdobbie Galt4 years ago
Did you know that on You Tube someone ran a petrol generator completely on hydrogen and oxygen that the generator made itself from water? I am not completely sure if the video is fake or not but they claimed to have powered a 200 watt load with it. No use for hovercrafts but its just a thought that maybe this technology does have some uses.

Unless someone verifies those claims through a testing lab, I would refuse to believe it.  You cannot get something for nothing, which is what they are claiming if I understand things correctly.  There are no easy solutions to the energy question.

I doubt very much that the video shows anything legitimate.  Most of the time these "breakthroughs" turn out to be measurement errors, a lack of understanding of the results, or someone fudging things behind the scenes.

I would love to be proven wrong, but very few of these "inventors" have ever submitted to rigorous third-party verification of their claims, and those that have discovered they'd made mistakes.

Water itself contains latent energy so i am sure that's got something to do with it. They must have a very efficient hho drycell and pwm controller. Or they are just messing about. Funnily enough, when I asked them about it, i recieved no reply so that makes me suspicious.
Water is an extremely stable compound, and that's why you have to ADD energy to the system to get it to split. There have been attempts to make this happen a bit easier, from heating the water (extremely hot water electrolyzes easier) or using various catalysts. The bottom line is that water is a very impractical source of hydrogen for anything but a fixed installation precisely because of the amount of energy needed. You would be better off avoiding the conversion losses and using the original energy source itself.
espdp2 sdobbie4 years ago
But LITHIUM batteries drowning in a lake are fine! :-)

Be careful, and I would love to see your 'ible when you get finished.
jlong-3 sdobbie4 years ago
Because the environmental impact of creating Lithium Polymer batteries is so low, not to mention the eventual resources needed to properly recycle them after the fact.
Why not just say throw a nuke engine on there.

If you hadn't noticed, it's a weekend FUN project. You want a hovercraft powered by lithium batteries and a brushless motor...hey fill your boots. Once you finish it let us know the costs and post up an instructable.

BTW great job MickyDee. I'm going to give this a shot sometime over the summer. I have an older 12HP Toro riding mower in the barn I've been trying to figure out what to do with. This looks like a great project especially with the ready made kits from universal hovercraft. Very cool!

No such thing as miniturised nuclear reactors as far as i've heard.
i could supply uranium, but of course i cannot sell it to you for that would be illega,l, you can have it, though you will pay ythe water bill for it, because if the uranium is in my tapwater.
I live in Utah where there's a LARGE source of uranium. Perhaps I could hook you up with some. ;)
Jk, that would be beyond illegal.
There is no uranium in tap water, the water is just radioactive!
well batteries take ages to charge and can be really dangerous as hightekrednek2396 said when they get wet. i find a petrol motor great as you can quickely refill it and it is far safer that a large amount of batteries. also, batteries can create a weight issue. i think how he did it was perfectly fine
Or he could have used a tank of hydrogen and burned the hydrogen in the engine. As if it was a normal gas engine.
Instead of batteries couldnt you use a solar panel and some super capacitors then you solved the battery problems.

And lipo batteries arnt cheap and very dangerous to people who don't know how to use them properly. And if water gets on them you better be able to get away from that boat immediatly or it's going to get very bad quick.
jlprice sdobbie4 years ago
What do you mean it would be better? Why would it be better?

If that were actually physically possible that would be a great idea. But of course it isn't possible and you don't know the difference.

Before you poke at other peoples work you should at least Google or check wikipedia for technical parameters. or rent a clue perhaps.

This is a great instructable. I look forward to seeing more about this project.

Why? Added cost and weight and limited running time would be better? Other than getting a warm fuzzy about it being "green" I don't know why else you'd bother.
Or maybe just 'cuz we have a leftover DC 1/4 hp motor laying around? :)
lol :) I supposed that's about as good of a reason as any! But the batteries cost a fortune right? If I were going to buy that many batteries I'd put them in a VW bug that I could drive everyday. Green or not, these gas prices are RIDICULOUS! :)
There are lots of plans out there for RC or model electric hovercraft but I don't see any adult sized. Is this even practical?
jackhg4 years ago

great project, looks good, I am happy the project worked well for your group, nobody was hurt, everybody had fun with hc.

let us know what you doing in the future

mickydee (author)  jackhg4 years ago
I would like to play with my Arduino Uno and try to build a balancing robot.
It's funny you mention the Arduino... I am in the middle of building a model hovercraft that will be semi-autonomousand plan to use the arduino uno as a system to help prevent crashes and aid in properly steering the craft as I'm sure you discovered it can be a little tricky steering.. for me if felt somewhat like driving a rear wheel drive car on an ice rink. Once I have my prototype all worked out I plan on scaling it up for use on a Universal design hovercraft... tghey really are the best. If you watch any hovercraft races you'll notice they are always among the top performers. As a side note in my quest for all things hovercraft I discovered goldstein hovercrafts llc sells some wonderful low priced kits for experimenting with hover-crafts and I highly recommend their R/C kit, it is a blast and I put the kit together in less than hour, they include tons of spare bodies and parts to encourage experimenting . I'll see if I can throw together an instructable on the model unit and hope to have a full size craft as cool as yours for my son when he is old enough! Kudos on a GREAT instructable!
mickydee (author)  mark4293 years ago
have fun! I think making a model would be a blast. I checked out the Golstein site and it looks like a bargain. The kit would save you all the trouble of finding motors and props, and ducts. I would prefer a larger model myself . Let me know your progress
Great Hovercraft! Please let me know as soon as you build or have instructables on your balancing robot. I have just bought an Arduino Uno and was wondering what to do with it!
steven13243 years ago
On my iMac, there is no sound.... I wonder why? Maybe instructables doesn't work perfectly with macs. I usually have to work around lots of problems.
Xx5mike5xX4 years ago
Could you please explain this step a little more detailed? It is kind of hard to understand what to do.
mickydee (author)  Xx5mike5xX4 years ago
The main purpose in bagging is to make sure the fiberglass is pulled tightly down to the work, eliminating air bubbles.
1. after thoroughly wetting the area and laying on the fiberglass cloth cover it with a thin plastic sheet. the kind you buy at the hardware store. you can even use painters drop cloths. this prevents the epeoy from sticking to anything.
2. cover this with an old blanket. This step adds weight to help the vacuum to pull into tight places like corners.
3. Now cover the entire thing with another layer of thin plastic sheet. It must be a little larger than the first one because you have to tape it to the floor. Cut a slit to insert the suction hose of a shop vac just under the last plastic sheet.
4. Turn on the shop vac and you will see the top sheet pulling down tight against the blanket. Over a little time it will pull down even tighter as all the air is pulled out. It is really fun to watch. After a couple hours you can turn off the shop vac.

5. Let it sit over nite and when you remove the plastic and blanket you will see a nice smooth area. The plastic film wont stick to the work and will leave a nice smooth finish.

I hope this helps you understand
Dear Sir:
Your instructable is both complete and easy to follow.
Thank you for such a well explained instructable.
Jesse M.
This is great!! The point of the blanket, though, is not to add weight. It's to create a channel through which the air can be sucked. Without the blanket, the two sheets of plastic will be sucked together close to the vacuum hose and the rest of the plastic will be unaffected. Great instructable!
pdagrizley3 years ago
i love both your instructables because they are complex and really well written
rocketman204 years ago
How much does it weigh
Thats a sweet ride you have there! I'm glad I came across this instructable, I saw a hovercraft on the Auction Hunters show a few weeks ago and have been dying to get one. Now I'll be able to make one myself :)
Cubie24 years ago
Wow. Totally unrealistic for me to build right now but I commend your work- that's awesome!!!
mickydee (author)  Cubie24 years ago
Thanks I really appreciate your comment
Maybe a couple removable rudders under the craft for driving it on water would help improve stability. they wouldn't have to turn I doubt so they could easily be removable.

All in all incredible build you guys did amazing work on this.
mickydee (author)  the_burrito_master4 years ago
I thought about that remembering my sailboat days. Lowering the center board. Without it sailing would be extremely difficult. Maybe if they were hinged to allow the to rise up when you pass over dry land.
thanks for the comment
Hmm possibly, I don't think it would be to difficult that way, tho there would have to be some extra small slots sticking up from the main hull.

tho then they woulndn't be easy rig up as a rudder.
now i need to wait until the blades on the 10hp wood chipper to get destroyed
peltierd4 years ago
What's the total weight? I'm curious about the power/weight ratio and I can't find any recommendations.
mickydee (author)  peltierd4 years ago
I didn't weigh it but it was really light. The fiberglass can really add up if you are not careful. I plan an instructable on how to lay up fiberglass with a minimum of weight
Galt mickydee4 years ago
I've used strip layups on stations strung along a strong back, and stitch and glue to build kayaks that were finished with single plies of differing kinds of cloth sandwiching the wood with great success. Temporary hot glue mounting of Western Red Cedar strips on plywood forms with a single layer of cloth on each side has proved the best combination of strength to weight for my prodigious posterior in a water craft. 18' sea kayak weighed less than 40 lbs. using epoxy resin. The methods are all pretty well tried and true in the small boat / kayak / canoe building hobby. How about a strip built hovercraft styled like the mini-sub from the Seaview? A sort of Amish meets Starship Enterprise look. Your build did kind of evoke the Seaview thing for me when I first looked at it. Once again...very cool!

Also had a thought on alternate power (no not another diatribe about the evils of ethanol). My great uncle still builds and flies ultralights down in Florida using Rotax/Bombadier engines I believe it was. I'm not up on all of the choices, and fully realize that you already had an engine that you were re-purposing, but the power to weight ratios of some of the snow mobile and motorcycle engines look pretty sweet. How about an old earth unfriendly two stroke?
mickydee (author)  Galt4 years ago
You are absolutely right about the Rotax engines. The power to weight ratio is terrific. I am quite familiar with them as I have built small airplanes using them.
They are however pretty expensive. Most of the factory built hovercraft use either the Rotax 503 (48hp), or the 583 (65hp). These engines are aircooled and only for the very serious builder. I wanted to keep mine simple and cheap
Google, "Universal Hovercraft" and click the UH-10F model on the side, it has all the specs as well as parts from just instructions, to buying the whole kit. Good site.
branonls4 years ago
Awesome build! My only question is: Where are the rockets and machine guns?
mickydee (author)  branonls4 years ago
they are hidden just like the flame thrower and the smoke maker
And the grenade launcher an chainsaws.
jlkinetics4 years ago
Adding little wings will greatly help lift when at speed. Even the tiniest surface area of an aerofoil will make a substantial amount of lift due to ground effect.

Just a thought, great instructable!
mickydee (author)  jlkinetics4 years ago
Good idea. They eould have to be easily removable though . The trailer is only so wide
Perhaps you could add one similarly to an airplane. It shouldn't be all that much work and could also be trimmed for different pilot weight. A slot could be cut in the rudder to allow room for it. I think of it this way because it looks like it has a rearward C of G and that adding an aerofoil to the rear behind the prop could even provide lift at low speeds and wouldn't alter the center of pressure much as it goes through the air.
ArtfulAl4 years ago
looks like the mach 5 from speed racer! only in hovercraft form!
Could it hydrodisplace water?

aka could you drive it on water?
mickydee (author)  instructoman994 years ago
It runs best on water
epic sonic4 years ago
astrong04 years ago want to make one..... what do you think could be done if a 1998 ford explorer 4.8 litre engine would be able to do? probably fly with some wings.
espdp2 astrong04 years ago
Universal Hovercraft sells a "ground effects kit" that adds wings to these things - at least to the bigger models - and lets them cruise at 4-6 feet and "jump" up to 20 feet vertical to clear obstacles!

$60k++ though...
mickydee (author)  astrong04 years ago
Wow what a beast that would be. It would have to be BIG to support all that weight.
Marsh4 years ago
It's pretty good, but it looks like you could use some more horsepower and a prop that will move more air. An easy swap that will dramatically improve performance.
mickydee (author)  Marsh4 years ago
You ae probably right, but I didn't want too much power because I wanted the kids around here to be able to drive it. It is built to take up to 15 HP.
Is the paint scheme based on the mach 5 from the Speed Racer cartoon? Reminds me of that.
mickydee (author)  stagebuilder4 years ago
No the paint scheme is because I only used straight lines. Curves are too hard to tape
The spaces between the lines are the width of the tape I had handy at the time
haryanto4 years ago
It's a good idea and I like to see your another post.And I hope someday someone will make a magnetic anti gravitation,any idea?
Maybe you could be using superconductive magnets,like the ones used in the Cern accelerator.The only problem is how to keep them cool(1K)and make them lightweight an compact.This is my presentation of what antigravity hovercraft should use for levitattion.Any one has more ideas???

I think,at first we should know how gravity work more than just light weight gas in a baloon.Without our consciousness we are all swim in the sea of gravity.
FyreAntz4 years ago
That's how you make those epic memories! Fantastic 'Ible! Thanks for sharing!
gamer70014 years ago
dude, like i need to see a video of that thing. it looks awesome!
calenso4 years ago
What do you do to prevent hands going into the prop? Can you screen the shroud, both sides?
mickydee (author)  calenso4 years ago
I put a wire fencing screen on the inlet side right behind the seat. I didn't screen the back side. The rudders keep you from getting close to the prop and it just seemed like unnecessary weight. You would have to try real hard to get your arms in there
Vinsu4 years ago
Looks pretty fast! Nice!
awesome, I have been looking at this kit for years now. That and the base model below it that uses just a lawn mower engine.
mickydee (author)  iminthebathroom4 years ago
Looks like a good one and the cost is just right
EmmettO4 years ago
I've never seen such a simple approach to vacuum bagging! Did you come up with this or was it in the instructions for the hovercraft?

The fiberglassing could really be an instructable all by itself!
mickydee (author)  EmmettO4 years ago
I think it described it some what in the plans, but I have been using this process for a long time. I built a 125 HP Fiberglass aircraft a few years ago and this was really important in the construction.
I love your work! I did this with my dad a while back and we had a great time. I actually bought plans from universal hovercraft that are still sitting under my bed... we ended up ditching everything except the overall dimension and built it ourselves.

We ended up using a thin skin and ribs to support the craft, and our skirt material was a rubber backed ripstop nylon (EXTREMELY durable stuff!)

overall a very fun project, I'm sure you two had a blast with this! You should look around the webs and try and find a "hover-in" where hovercraft hobbyists come to show off their hovercrafts. It's a BLAST to have 20 or so hovercrafts out on a lake puttering around, especially when the guys with jet engines mounted on their craft get out to show how it's done at ~80mph.
mickydee (author)  thecheatscalc4 years ago
Thanks! Bye the way I really enjoyed your Sterling Engine ible Great job
You said you didn't know how fist it went but could you give me a rough estimate.
mickydee (author)  coolpizzadude4 years ago
This is just a guess, I would estimate the speed over water to be 20 mph. I never took it to a place where I could let it out on dry land.
rimar20004 years ago
You have done an excellent work, congratulations.

I always ask me how do those vehicles brake.
mickydee (author)  rimar20004 years ago
Braking i real complicated you have to pull back un the throttle and squat
Pardon, I don't understand the word mickydee, and Google Translator don't help me.

Is it the propeller thrust reversible in some way? That could help, I think to brake quickly is more important than getting a good speed. Anyway, the genuine "all surface" condition is very valuable. Can the vehicle go up a soft uphill? (ie, a beach)
Basically the problem is this, you're floating on a basically frictionless surface

(if out of water, in water there's drag effects associated with the surface tension, it creates a bowl that you're constantly trying to get out of IE an uphill in every direction. Once you exceed the wave speed of the water, you escape the 'lip' of this bowl and drag is dramatically reduced.)

When floating on a frictionless surface, if the surface is slanted, you move in that direction, AND the thrust from the back is your main form of acceleration/deceleration. If you're on a flat hard surface, say a parking lot, the only way you're stopping is this:

1-throw an anchor to drag you to a stop
2-reduce lift until the skirt drags and you slow to a stop (or put rubber/plastic blocks on the bottom to keep the skirt from bearing the brunt but the pads instead drag)
3- turn the craft around and use the propulsion to slow you to a stop.

When you're on water, because of the previously mentioned "bowl" effect, you'll naturally slow down a good bit as it is, but if you reduce lift enough, the skirt will begin to drag and you'll quickly be reduced below wavespeed of the water, which will further slow you down.

Ideally though you just use the back thrust until you're slow enough to drag to a stop without harming your craft.
Sorry to double post, but I left out something, YES hovercrafts can go up a low slope, it's all determined by the amount of thrust you have. If you have a 400lb total mass and you're going up a 10degree slope, there's a force down the slope

400*sin(10) = 70lb thrust needed to stay stationary (or at a constant velocity).

So, in reverse, if you're able to output maybe 30lb thrust, it's

inversesin(70/400) so about a 4 degree slope. etc

However, most the time you build up a good speed before hitting the slope so that it gets you over the slope before your momentum is burned up.
mickydee (author)  thecheatscalc4 years ago
Boy are you over my head with those calculations. I will run them by my grandson when he comes home from college next month. He is majoring in physics with a minor in math and computer science at Duke. I am really proud of him
Mickydee, great project. And what says the most about it is that you took the time to do it with your grandson.

Gotta looks pretty cool! Thinking this might be something that my son and I might like to try. We have a pond near the house...
Thanks for the info. I still think it is a rather dangerous form of transport. The risk is boosted for the fact that having low friction, is easier get a high speed.
Because they are so dangerous that's why the U.S. Navy and Coast Guard use them and not civilians right? Some people are so dumb about things they don't understand. You have the internet, use it! This is not some strange technology that aliens have shared with us recently. It has been commercially available at least since the 1960's.
Thanks for the praise, you are very gentle and polite.
I'd just say that there's a reason they're not used for everyday travel :P

BUT there are some uses where the hovercraft is ideal, EG going up rivers/rapids, open water, or amphibious uses.

It's fortunate that most lakes are usually not crowded!
mickydee (author)  thecheatscalc4 years ago
You are right. When we built this thing we planned to use it on water only. I don,t have a place to run it on dry land. It stops fine when we chop throttle on thr water with no damage to the skirt.
The word "mickydee" is the poster's name. He was basically signing his comment. It wasn't part of the instructions. :D
Yes, I am a dumb old man... Thanks.
You are not! Believe me, lots of people can misread things online- it definitely doesn't mean you're dumb. *smiles*
nerys rimar20004 years ago
no mickydee is his NAME :-)

basically when you cut power the HOVERCRAFT will squat as less air goes to the cushion dramatically increasing your "drag" in the water and on land and killing your thrust slowing you down.

there are no real "brakes".
rimar2000 nerys4 years ago
Thanks for the info. Really hovercraft is a dangerous vehicle. Very fun, but dangerous.
skaar rimar20004 years ago
not terribly dangerous, lots less dangerous than a wheeled atv.
Commercially produced hovercraft have two scoops, one on each side on the fan. They don't obstruct the fan when going forward, but upon pulling back on the lever, they force alot of air 180degrees to stop the vehicle, and it stops it quite quickly. I built one of these awhile back, the UH-10F and I used the scoops for braking. And I was going to post instructions on my blog but they were not happy with me. The odd thing was I didn't use anything of theirs, I used a picture from their website and had to calculate everything from their pictures, but I guess that is close enough to copying for them, and it looked identical to theirs. I guess that is understandable, they would lose money if people continually posted the instructions they sell online for free.

As for inclines, yes it will go up inclines, but they won't go up a hard incline for long. gentle slopes are ok, or if you have a short, but steep hill, you can gun it, get some speed on the flat and sometimes get up, but they generally they don't like hills too much. That might be solved with a larger prop and more powerful engine. I used a Wisconsin hay baler engine, and, although rated at 9.2hp it has way more torque then a standard 10hp engine (Not to mention, they are built to last) and I was planning on putting a larger fan on, just to see what happens. If the larger fan doesn't work, there is a dedicated site to Hovercraft parts (I don't have the URL on me, but if you want it I can find it) and they sell fans that will handle higher speeds, even if their diameter is the same, and using a gear ratio system to drive the fan faster (This only works if you are using a gear reducer or a pulley drive system or similar. If you are using direct drive this method won't work because the only way to increase the fan speed is increase engine RPM, and this can lead to over revving and eventually parts exiting the engine block at high speed=very dangerous).
Thanks for the info, I don't propose to build a hovercaft.

Regarding the propeller, I would try one having variable blades angle. There are theses for ultralight aircrafts.
That might work, I dunno much about ultralights or the blades they use. Might get too complicated, but would be cool, especially if you can reverse pitch to brake the craft.
Hmff4 years ago
Will this fly over water?
kleinjahr4 years ago
Very nice. What's next a landspeeder(aka WIG)?
mickydee (author)  kleinjahr4 years ago
That would be great if I could figure out how to do one I would sure give it a try
skaar mickydee4 years ago
there's one on here somewhere, it's wheeled, springs, no shock absorbers, so it bounces like it's floating.
lfahrney4 years ago
Very cool! Having worked with many military and civilian hovercraft, this gets my heart pumping. Flying the things is definitely a skill, but well worth learning.
Thenwcp4 years ago
Built that very same hovercraft when I was in highschool,made the Engineering class very popular haha
Very Nice, MickyDee!

I was going to make one of these about 30 years ago.
I have the Popular Mechanics Plans, that I purchased about 30 years ago.

I lost the instruction manual, though..

It was the Popular Mechanics Pegasus. 1983.

GREAT job!
mickydee (author)  Greasetattoo4 years ago
I remember one from years ago that was round like a saucer and had little doors that opened up around the skirt . It looked kind of flimsy though and I was too young to build it. In those days kids were building crystal radios
Oh, just searched google..

I found the plans for sale here:
cheekypaper4 years ago
Good grief!! Look at that workshop ! :~)
or was it in an operating room?
mickydee (author)  cheekypaper4 years ago
My workshop is my pride and joy. It gets a little messy at times but it doesn't take long to clean it up. My best friend has a workshop with all the metal tools I don.t have. He has a vertical mill , metal lathe and tig welders. plus things I don't even know what they are. Between the two of us I think we could build anything
dagob4 years ago
This is a great project, I think I'll build one as on scale for R/C and see how it works. Thanks for sharing!
mickydee (author)  dagob4 years ago
I have thought about the same thing. I have a 4 channel RC unit and I think I will build it using an electric motor. It should be a blast.
giles26064 years ago
Wow! Really impressive instructabele - wonderfully made - simple where it needs to be and with great art where needed too - you should get a great grandpa award! I know my own grandpa would have been impressed too, bravo.
mickydee (author)  giles26064 years ago
I have always tried to be involved with my grandson. I coached his entry's in Science Olympiad and we had a great time. He entered Robot billiards and Indoor rubber powered airplanes. He won a total of 5 Gold and two silver medals.
He is a sophomore at Duke now
ilpug4 years ago
This is amazing. I want to do one of these for a college project. you get full marks for EVERYTHING.
mickydee (author)  ilpug4 years ago
Thanks I really appreciate that
Mitt4 years ago
How many hours to complete this project?
mickydee (author)  Mitt4 years ago
I didn't keep track of time, but overall we spent 2 months .The most time was spent waiting for the fiberglass to harden
sub8934 years ago
Very cool! You should put a video of you driving it!
threefer4 years ago
Wow, it's so quiet. :)
Wesley6664 years ago
As posted by someone below, and because it is of utmost importance, please, buy some steel mesh and put on BOTH sides of the prop preferably BEFORE someone loses an arm/limb. It looks to me in the last picture that you may have some on the front, but I would highly suggest some on the back as well if you don't already. People assume since air is being blow out the back that limbs can't go in there, but they do.

This applies to everyone and should apply to any project -- Safety is key and just to emphasize it and does not get missed:

jhd044 years ago
Yes!!! You and your grandson rock!!!

Here's to ambitious dreams... and bending the rules at a young age.
rangeside4 years ago
Nice project! This is one of the few that seems like it would be worth while. Thanks
omnibot4 years ago
Best .. grandpa .. ever !!
EmmettO omnibot4 years ago
I'll second that!
nanosec124 years ago
Nice tip about the vacuum and blanket. Thats going to come in handy on several projects.

Great Job on this one, I hope you and your Grandson have as much fun playing with it as you did making it.
mickydee (author)  nanosec124 years ago
Thanks we have
techmonster4 years ago
man i wish my grandpa was like this
mickydee (author)  techmonster4 years ago
Thanks it was a labor of love