Hovercraft

This is a full size(4ftx8ft) one person hovercraft built over one summer for less than $200. It was built with no prior experience or knowledge of hovercrafts but with sheer determination to build something different. So check this project out, hope you like it.

Disclaimer (March 2013): I have not made any changes to this Instructable since the early days of this website, 2006.  Take this Instructable as an example of how not to build a Hovercraft.  The homemade thrust fan and unshielded rotating parts make this homemade craft pretty dangerous.  If your building a hovercraft of your own please consider the safety aspects large rotating parts and apply this understanding in your design.  For a great example of how to build a working and safe hovercraft see this Instrucable 10-HP-Hovercraft  

Step 1: The Skirt and Base

Lets start out with a little history, I built the hover craft during the summer between my sophomore and junior years of high school. It was built by a good friend, Brain, and myself Doug. Like I said I built the entire craft for less $200 including the engines and the fans. I will explain how I did it soon but lets start out some of the main things you will need to get started.

3hp Horizontal Shaft Engine $50 at a local lawnmower repair shop
4hp Vertical Shaft engine took it off one of my lawnmowers
5.2 moisture resistant Lauan Plywood 4ftx8ft
Styrofoam 4ftx8ft
1/2in Plywood 2ftx4ft
A couple 2x4 8ft
A couple 1x2 8ft
1/4in bolts and nuts 1in- 3in
Wood Screws 1/2in - 1in
Plastic sheeting Painters Sheet (this is the skirt material)
Brass Grommets with punch You can get this as a kit

This is about what I started out with but in no way is this everything youll need. Also keep in mind that this is how I did it, if you plan on taking on a project like this do it how you want to and with what is available to you. Use this as a guide so that you do not make the same mistakes I did.

Lets start out from the ground up. On a hovercraft the only thing that touches the ground is the skirt. The skirt is the part of the hovercraft that holds air to lift the craft. Like in the second picture my hovercraft has two engines, one for lift and one for thrust. The lift engine pushes air under the craft and the skirt holds the air in. As more air is pushed under the craft pressure builds up and lifts the hovercraft off the ground. This is how a hovercraft hovers, the only thing in between the base of the craft and the ground is air.

But before I designed the skirt I designed the base of the craft. It has to be light(this is the most important) and it has to be strong enough to hold the weight of a person and the engines and everything else. Keep in mind though that when hovering the craft is actually more stable than when its not. The air pressure helps to hold the weight evenly over the entire craft.

This said here is how I made the base. I got two sheets of 4ftx8ft lauan and a piece of 2in thick Styrofoam. The lauan was the cheapest and the lightest sheet of plywood I could find at home depot. One note, I got almost everything for this hovercraft at home depot. Lows or any hardware store will probably have the same items I got.

The base is just the two sheets of plywood with the Styrofoam sandwiched in between. Holes are drilled all the way through this sandwich and bolts are used to hold all of the components on the base.

Back to the skirt which is one of the more trickier parts of a hovercraft. It has to hold its shape under pressure and it has to be the right size. To big and it will drag on the ground which will slow the craft down or not let it move at all and to small and it will not hold enough air to sustain lift.

To overcome this I designed my skirt to have 8 different pieces that I sewed all together with nylon string. For each of the four sides of the craft there are two skirt pieces. A upper half and a lower half, which are same shape. The picture shows what each part looked like. Basically the same design for all four sides just different lengths. The skirt is actually smaller than 4ftx8ft by 2in on all sides. This is done so that the skirt can sandwich between the Styrofoam and the top piece of plywood. So you will need four longer skirt pieces and four shorter ones.
Each piece first needs its flap folded over and sewn. To sew the skirt I used a standard sewing machine and sewed along the seam lines which are 1/2in from the edge. Now take two pieces one short and one long and sew them together at the angled end. Now do this again for all the other pieces to form a two rectangles. Now put one rectangle on top of the other and sew along the outside perimeter. This forms the whole skirt but its not done yet.

Now duck tape along the seam for added strength then flip the skirt inside out so the seams are in the inside. Punch holes on the inside of the skirt in the middle of the flap on the top and the bottom of the skirt with the grommet kit. Put holes on all corners and every foot along the length of each side. Drill holes through the base that line up with the grommets. Sandwich the top of the skirt between the Styrofoam and the top piece of plywood and then use 1/4in bolts to hold it all together.

This completes the skirt and the base. This is the most general part of the build. The rest of the craft is built specific to the engines, fans and components I used, you will have to adapt these plans to fit your components.

Sorry about the pictures I could not get them to show up very well. I included the DWG file though. The last picture is the overall skirt put together showing the flap folded over with the dashed line and where holes should be put with the circles.

Comments

[KrystianEly]

i have a prodject in college where we have to use the information over the 2 years to build something, everyone chose a go-cart but i chose a hover craft im building this on my own, do you think it will be worse if i was to add slightly bigger engins? thanks.

[pavilion89]

My craft is about 8 icnh height, 8feet length, 4 feet wide and capacity for a person only. is 2.8hp enough ?

[dbc1218]

I don't think that will be enough unless the craft is very light. check out this http://www.instructables.com/id/10-HP-Hovercraft/ same size but uses a 10hp engine

[pavilion89]

what is the suitable material to built a fan for engine of 2.8hp?

[dbc1218]

I would not recommend building your own fan, especially not like the steel fan I built for this craft. Most fans/props I've seen are made from wood or have plastic baldes connected to a center metal hub. Also, if your building a craft similar in size to mine, 2.8hp won't be enough power.

[assaultpioneer]

Wonder if you could make two smaller almost hoverboards connect them to make a hover "pontoon boat" or catmeran

[Dovim]

hey, awesome guide. i have a couple questions though. how fast can it go? can you make it have more surface area while using the same skirt and engine setup? and i thought of a way in which the forwards thrust fan might be replaced by a spinning wheel which could be lowered and maneuvered like that of a motorboat (i don't know very well how to explain it). thanks

[dbc1218]

It didn't really go anywhere, read the last step. Why would you want to make it bigger? If you did make it bigger with engines similar to mine, it would be way underpowered and probably not hover. An outboard wheel could work but I think it would defeat the purpose of a "Hover"craft

[Dovim]

Ah, i see. so it was too heavy for the fan to actually accelerate it, right? well, an outboard wheel would solve that problem, i think. also, i see the purpose of a hovercraft as a vehicle that can go on land and water, so if the outboard wheel could also be used as a fan in the water, then the purpose would be complete. also, an addition of an outboard wheel would lead to the only speed limit being air resistance, since it doesn't touch the ground (as different to all other vehicles), whereas the wheel could be lifted so it didn't touch the ground. the result is it could just keep accelerating and accelerating. The results could be interesting. The thing about making it bigger was merely curiosity, though. i can see that it would have no practical purpose, and if i could make it smaller without losing stability, then it contributes to making it lighter, thus faster. As i said, the results could be interesting. i'll have to do a lot of thinking on it, but the hovering mechanism of your hovercraft seems like a great way to start.

[double_g]

I'm not sure if this is true as I'm rather new to the hovercraft scene, but from what I've read it seems that increasing the area actually increases the lift generated. I'm not sure where the page was that said this but if you crunch some numbers on the following website you'll find that this seems to be true. http://www.olshove.com/HoverHome/hovcalc.html
If someone can explain this it would be much appreciated, since I haven't yet figured it out (I'll ponder on it a bit more in the meantime and see if I can come up with a logical explanation).

Of course weight to lift gain must be considered.

-hope this helps future builders

Double_G

[dbc1218]

If you increase the size of the craft and therefore the area the pressure needed to maintain lift will decrease but the amount of air needed to be forced under the craft will increase. This usually means you have to use a different fan or a more powerful lift engine. During the design of the craft you have to decide what you want. If you want a bigger hovercraft you need to match that with the right size engine and lift fan, but if you already have the engine size set then you need to decide on the right size craft. The guy that created that site from your link says he used Hovercrafting As A Hobby to create the calculator so I would start there.

[double_g]

Thanks I built my hovercraft for my high school senior project. I've planned on making a bigger better version so I'll definitely take your advice for that if I ever get back around to it. Alas plans for the new version are in a long list of projects not the smallest of which being my senior project for my undergrad in electrical engineering.

[Pfarmkid]

how did you make the steering controls?

[threewingwonder]

You could build your own fans from wood, all you would have to do is check out Universal Hovercraft with a search. I have built a hovercraft from plans that I got from them. turned out to be a very versital craft.Mine was 6ft x 12 ft and had a 5 hp lift motor and a 30inch home made lift fan and 2-5 hp thrust motors with 48inch homemade thrust fans. I now have plans for a little bigger craft for exploring. You should really check out :Universal Hovercraft, they are based in Cordova Illinois. A very good place to start a hovercraft adventure.They have plans,supplies and advice/tutorails for hovercraft builders.Great ible though

[Pfarmkid]

How much did it cost?

[PickPacket]

That looks safe..

[pufferboytbh]

THIS IS IN NO WAY SAFE. For our cadet's "Pioneer's" platoon (building stuff), we built 3 full sized hovercrafts for use. The prototype on it's first run tore itself apart, srapel flying everywhere, nearly killing myself and many other cadets. In building these hovercrafts, ensure that there is a metal mesh over the air intake (and outakes) and that the propellers are insulated in metal. Depending on your propller speed. Have fire equipment ready. Being 14, I don't want me or my cadets to die.

[Jaredicus]

What branch JROTC are you? I am army JROTC.

[pufferboytbh]

By the way... The same thing happened about a month later. With the metal, the propeller stayed in the engine housing, causing only damage to the engine, housing and propeller. The hovercraft remained floating, while we remove the two year seven cadets from the craft, set up a perimeter, and killed the engine. The craft didn't even sink! MUCH SAFER.

[szulli-randall]

Does anyone think it's possible to make it hover a few FEET off the ground?

[jbowman7]

they're called hoverwings, google it

[szulli-randall]

I ment without wings.

[jbowman7]

Then no, it's not possible, the skirt has to be touching the ground to maintain the air cushion. but you can still hit jumps with a sturdy hovercraft. Look up hoverwings though, they're cool.

[dbc1218]

Large hovercraft, like the ones the military use, hover a few feet off the ground but that height is sort of proportional to the their size. A small hover craft that hovered that high would most likely by unstable, remember your sitting on air, so nothing but your balance will keep you upright.

[iminthebathroom]

Not sure if even they hover that high actually, maybe periodically though

[geckomage]

will this hold a 260 lb person like myself? :P i normally go muddin in my truck when i wana have fun driving something. but this'd be fun :D

[gopalrr]

hi,

can you share details of how you did the 70%/30% distribution of air thrust to lifting and propulsion ?

gopalrr

[dbc1218]

that distribution is typical of a hover craft that uses a single engine to turn one ducted prop. the duct is split to divert 30% of the air underneath the craft for lift and the rest for thrust. My hover creaft used two engines and fans so that distribution is different

[rocketman20]

Where did you get the fan you used for trust.

[dbc1218]

I made it from sheet metal and angle iron, but I would not recommend doing this at all. Get a purpose made prop thats been properly balanced.

[elina0]

OMG! This seems me too heavy..

[rbland]

you probably want to put some sort of cage around the vents too: http://www.stuff.co.nz/national/5380361/Auckland-man-decapitated-testing-hovercraft

[rocketman20]

Are the Brass Grommets just for attaching the skirt to the base? Also does the skirt have holes in it? I am trying to build a hovercraft myself but am having a hard time understanding how the skirt works.

[dbc1218]

they are just for attaching the bottom edge of the skirt to the base with small rope

[jdhover]

so is your base piece hollow or is it ducted?

[dbc1218]

its a sandwich of t pieces of 1/4" plywood with 2" of Styrofoam in between
.

[nibbler125]

you need a real fan that metal one has no airfoil and you could easy double youre lift with a good wood one it will cost allot more tho up to 200$

[ss2pheonix]

or just make one yourself, assuming of course you have basic air foil knowledge and the ability to carve

[ss2pheonix]

i think i would have used one 12hp engine or bigger from a lawn tractor and rigged the mowing deck to feed the air for the lift and controlled the drive fan with the drive train from said lawn tractor.

[ilpug]

nice. i think you need a much tougher more rigid skirt. i would also use a more powerful motor, or maybe two really powerful leaf blowers used together, feeding air in from two separate points, instead of one point.

[Wesley666]

This would work, what you need to do is get a 30in or larger diameter fan and maybe a 5hp motor for it, then it should hold the weight.

[cronama]

id like to see a vidio of that pimp wagon

[pindalanderz]

for the skirt why not use an inner tube for a tractor tire?

[cronama]

ive always wonderd that my self, you would think that the thick rubber would make it more dourable. my guss is that if you use one dont inflate it completly leave some slack, but then agin i have no idea

[weasel999]

the thrust fan..... u shud have ma it blow the other way and attached a sail

[hippopotamusofdoom]

it wouldn't go any where because it would be pushing the sail one way and the engine would be going in the opposite

[the_doctor]

well not exactly, if you were to make the intake vents point forward then it would pull and push in the same direction.

[naruto the ninja13]

can you put the back fan on a swivle for steering?

[dracoaliamin]

 Ok now that fan is a great idea but there are much more safer cheaper and more efficient mays to make that fan that puts air into the skirt. There are two main problems with your design. The first is safety. Did you consider what would happen if someone got there foot in there? The second problem is air escaping. It would be a good investment to put a skirt around the fan so that air could not escape. However the best way if you are building another one then it would be good to stick a leaf blower in a hole and seal the edges.

[jeroen]

yooh i dont understand how you make the ropes of undersite of the skirt to the undersite of the hovercraft

[pyroboy08]

I would bet a contributing factor to your inability to hover with the propulsion engine on is that you put your lifting engine to far forward. try putting it right in front of the propulsion engine and you sit in front of that. that may not cut it, but it would definitely help. you should seek a larger fan for lifting and a larger motor if nessisary

[BIGHAIRYDUDE]

just wondered if that specific hovercraft can go on grass and water?
how high does it hover?

[dbc1218]

It hovered about 6in off the ground, but I never tried it on grass or water.

[Rahdzhillaxxx]

Just curiouse of the notion that a squirrel cage blower might produce a more sufficient amount of  lift  per HP. I dont know if it does or not just thinking  it might. 

[littlewit]

Why doesent the side with the lift engine fill with more air than the opposite side? How is the air distributed evenly below the vehicle?

[geoslim13]

pressure the us military already solved it and uses hovercrafts that transport cars and people over land and water

[geoslim13]

heres a pic

[geoslim13]

and mike rowe got to change the skirt of one on his military special for dirty jobs

[tgo]

would a water bed matress work for the skirt or would it be too heavey

[vhayden]

There are ready made plans for using a water bed mattress for the skirt. If you are interested, let me know.

[geoslim13]

i am!!!! i know you aren't replying to me but i have a friend, well my grandmas friend that has become a family friend, that has a water bed and is thinking of getting rid of it along with his treadmill (different project) that could work.  it is a king or queen (whichever is bigger)!!!!

[Thelonelysandwitch]

use a thick tarp and duct tape

[dbc1218]

I think it would be to heavy.

[ilpug]

it works fine. canvas tarp coated with polyurethane sealer is perfect.

[holrob11]

how much weight can this lift with a 3HP engine?

[selstonator]

 dose it work????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[selstonator]

 can it carry a person on water???????????????????????????????????????????????????????????????????????????????????????????????????

[EI_Flyboy]

FYI you don't inflate the whole underside of the craft as this wastes lift, you just want the air coming out around the edges of the skirt as in this diagram:

http://en.wikipedia.org/wiki/File:Hovercraft_-_scheme.svg

On propellors, they must be balanced and the diameter must be matched to the max rpm of the engine so that the tips don't go supersonic at max revs because then bad things will happen! Apart from not generating any thrust the stress can cause the prop to fail catastrophically.

Plus if you intend using your craft over water you'll need a bouyancy tank incase the schtuck hits the fan!

[The Red Button]

have an engine but it spins clockwise when looking from the top of the engine. any idea where i can get a fan blade the will thrust when spinning that direction. all my electric fans are meant to spin the other way

[mechanixman]

what if you take model aircraft engines and use those instead of the heavy motor?

[oscarthompson]

I can see why you hover craft was too heavy If i was making it i wouldn't 1. use metal cowlings. I would use hard foam even polysterene 2. replace the 4hp lawnmower engine with a leaf blower or two (lighter wight) 3. reduce the size of he ply wood (not all of it is needed) 4.Use carbon fibre or a wood propeller for the thrust engine. 5. use a plastic fan for the lift engine 6. lighten the craft eg. do not use sheet metal or make hunky engine mounts But i think you did good..... Im gonna make it so these are the changes im gonna make.

[the_doctor]

You should try an ion propulsion system it would be quieter and smaller looking

[lane29]

sounds dangerous it needs some shrouds

[charles61]

Propeller has flat blades : much noise , bad aerodynamic and poor thrust.
You have to wharp the blades so that they have the same diametral pitch (at any distance of the center) . Furthermore, it shoud be good too to give the blades some curve (put a look on an airplane wing ) and to sharpen sligtly their trailig edge ...and make the leading egde 'round' . As a result you will obtain MUCH better performances : much thrust for less power !

[nomooremr.niceguy]

About how fast can you go on yours?

[bomberss27]

Great Job. I'm building one now about the same size as yours, and I wanted to know how I could attach this fan, http://www.qcsupply.com/Products/11455.aspx , to a 5-6 hp vertical shaft engine, the shaft would probably be 7/8" in diameter. I was planning on using this or just two leaf blowers, about 400cfm. Would the leaf blowers be just as powerful? I like the idea of the lift fan more but if it would be about the same as the leaf blowers, I think they would be easier to attach. Please respond, Thanks.

[dbc1218]

One of those fans could work but I would go with a horizontal shaft engine, so you could connect it with a belt and pulley like I did on my hovercraft. Also make sure your pulley ratio is correct so you DON'T EXCEED THE MAX RPM OF THE FAN, you'll need to govern the motor too. The extra weight of some sort of right angle drive to make vertical shaft engine work would be to much. Two leaf blowers would work but I would get at least 30cc each. If you are not using plans or have not built a hovercraft before expect to have to redesign something to make it work. Just keep working on it and you can make it work the way you want.

[pufferboytbh]

Hello again. If you want to only have one engine, use EXACTLY 11HP Honda engines. 11 Hp is good because it provides enough lift and a good walking speed, and honda because their engines are the easiest to start and they don't stuff up. By the way, this will be spinning at 3000 RPM so it is ABSOLUTELY CRUCIAL that you have a fan cover and a STEEL propellor hub. I used an aluminim hub, and after two years, it cracked and went flying. USE STEEL.

[bomberss27]

Sorry I was talking about the lift engine, I'm pretty sure you are talking about the thrust engine. For the lift engine could I just attach the fan to a vertical shaft engine with a hub or something? The lift engine on yours is a direct drive, right?

[dbc1218]

Alright now we're on the same page, the lift engine. The fact still is you can't connect that fan directly to the motor because you will exceed the the max rpm of the fan. A typical small engine like the one you plan on using will rev to 3000-4000 rpm so you will still need some reduction. A pulley and belt could do this and keep the rpm below 1700. The super hard PAG fan on that site is rated at 3300rpm but I don't think it will provide the cfm you need. I know the fan I used is very much the same fan that you are looking at and I connected it directly to the motor. So I am suggesting not to do what I did. I just want to give you the "safe" advice not the "it probably won't break apart and send shards of fan blade flying at you" advice.

[pufferboytbh]

I aggree with dbc1218. A 2:1 reduction helps. For my platoon (see post above) 2/3 of the hovercrafts used 2:1 gear reduction. They are softer, more stable, and don't lose rev's when you go with or against the wind. Also the one without the reduction seems to shake and break more easily... Use a heavy duty fan, and make sure it is NOT OFFSET in any way. That's what kills you. Get a fan that is rated for your rpm, and screw in ALL OF THE BOLTS. You don't need a reduction. The one without actually goes faster (slightly) than the reduction ones. The fan is the key. When not using a reduction, make sure you rpm is right, and take off some of the blades to keep efficency. (We went from 9, to 6). IN a machine going at 1500-4000 rev's, safety is your NO.1 concern.

[bomberss27]

Hey, I've got one more question. How does the thrust system on the xinventions hovercraft work? They attach a wood propeller to a weed whacker engine, and I believe that those have a really high rpm (like 7000-10000), does the wood propeller they use just have a really high max rpm? Thanks.

[dbc1218]

I'm pretty sure that prop was made for large model airplanes, so I'm sure it was made to spin that fast. I have seen that large of a prop at some hobby stores and surprisingly they are not that expensive either.

[bomberss27]

Yeah I've decided to go with a fan with a higher max rpm, something from universal hovercraft probably. I think this would be much more powerful than two leaf blowers, so I'll probably use the lift fan. Thanks for the help.

[abed 007]

can i know how mauch did it cost u waiting for ur reply

[danielwiseman]

[nrepak]

Not to be rude but how is this relevant to a hovercraft?

[dombeef]

What is that?

[ninanjijo]

hey bro can u tell how should i decide the size of fan blades to be used in hovercraft

[ninanjijo]

pls can u give us more detail about the hovercraft skirt part i am not able to understand how u have made the skirt can u give me the images of it

[Orro]

Hi Does it run on water?

[rybo1427]

im a little confused about the two layers of the skirt

[crazycommanche=US=]

plastic sheeting doesnt seem like it might be the most durable material i know that they make window shutters mad out of KEVLAR material it might be a little more expensive but more durable in the long run i dont know it seems like theat would be good you might wanna use a engine from a biggler peice of equipment possibly for both u might be able to get anothere person on there doesit it work on water if it can but not stable enoughe u could get some bamboo its really light would mkae a gret stabilzer

[tinkerC]

Do you think that an engine in the back for lift as-well would have worked?

[pufferboytbh]

By adding all these extra engines, you are increasing the weight dramatically. I is WAY better to use only one petrol engine, with one third of the air going towards lift. Make sure you us a VERY powerful engine though. That's what we did. (Read post above)

[tinkerC]

Maybe have a belt drive to drive one in the back?

[dansoffdawall]

Can it run on water?

[pufferboytbh]

Yes, read my post above. In an army range, we had to run it on water or there would be too much dust. It's faster and better to run on water.

[cooptroop]

what if you used two lift motors and just made it longer. that should support a more powerfull thrust motor and u could also use a different pulley ratio

[kevin007benny]

hey , i'm making one too. and i'm thinking of using an electric motor with a car battery to power it maybe. and do you think this will work ?

[theXmaker]

I think you have to add any safety to the back engine (a fan cover for example)

[jamesg07]

To get more lift could you use your one verticle shaft engine and run two fans off of it then you would only add a small amount of weight and would get more lift?

[james.mcglashan]

did u get this idear from escape from experament island because it looks the same

[deqwer]

wow

[coolpizzadude]

Dose you're skirt have to layers that are sewn together.

[dbc1218]

That is how I made my skirt but there are many different skirt designs. the skirt I used is called a bag skirt.

[rishabhjain]

hi... i am going to make a hovercraft like u made. i want u to please tell me from where to start.

[dbc1218]

Start with a lot of research into hovercrafts. Look an many different designs and then decide what you want. If its your first hovercraft build I would highly recommend buying some good hovercraft plans.

[dciocoiu]

insted of an shaft motor culd i use just an ordinary lonmuer moter?

[dbc1218]

I did use an ordinary lawnmower engine for the lift fan. The thrust engine is a horizontal shaft lawnmower engine, not a push mower engine. You can get a horizontal shaft engine of many rototillers or edgers.

[Derin]

Correction

Instead of a shaft motor could I use just an ordinary lawnmower motor?

[ravingking2008]

a safety gaurd would be a really good idea . safety first n all that. nice project

[beckervldejazz.com]

I am having trouble opening files dwg can you put the pictures right on Instructables.

[beckervldejazz.com]

you need more info on how to make the skirt.

[coolpizzadude]

show a picture of the bottom of the hoovercraft I don't know how the air escapes

[stevierobb]

one thing that i dont get the bottom side of the hovercrafts skirt how many holes do i have to put in it also what type of material did u use for the skirt??

[dbc1218]

The skirt is made from plastic painters sheet and does not have any holes. there are different types of hovercraft skirts and mine did not use holes.

[stevierobb]

but how did the air in the skirt get out to make it hover? if there was no holes the airs wouldnt escape? write back

[TripleP]

How did you make the skirt? can you show the bottom of it?

[dbc1218]

I don't have any pictures of the skirt from underneath but if you read the first step it should give you a better idea of how it was made.

[theXmaker]

hey, it's better than the other rounded hovercrafts that we see always, but I just wanna ask you: can't you put anything (a cover) for safety to the back 'fan' ???????

[guymark]

I am surprised at how few people have said "extremely well done", I wish I had had the initiative and determination to build a project like that while I was still at school. Sure it would have been even better if you had managed to get a professionally made fan - and safer too - but a huge bucketload of credit for actually making even the basic components yourself too. Seriously impressed - glad you learned a lot from it too, and excellent project and considering your age at the time, amazing resourcefulness and determination. Mark

[Prometheus]

Scary, my opinion exactly, and even with my own name too. I have to perform some "Hail Marys" now LOL

[tigerdog330]

How many hp do you recommend for the lift engine? I was thinking like 5 or 6.. Also would a weedwhacker engine would work for the thrust if I were to cut the stem and attach a prop to it?

[Prometheus]

No, a weed-whacker engine simply does not have enough torque to turn a propeller. A 3hp Briggs-and-Stratton upright utility engine would be much more appropriate for the application. You can also salvage the powertrain from a Honda "Spree" motorscooter or similar and simply attach a prop to what would be the drive to the rear wheel with a 20" propeller. Ideal would be the powertrain from a Honda "Aero 50", probably the most powerful moped-classed motorscooter to ever exist (built only in '85 and '86, and 70cc mods are apparently still available).

[awkrin]

so u can really ride it? anyways, it's funny how some simple instructables have high quality pics and this one, and many others that a simply "big", don't

[dbc1218]

I did ride it but it was really under powered.

[Prometheus]

Add another fan unit (for the airfoil) or upgrade the existing one and it might perform better. Ideally you want something like one giant innertube around the perimeter with enough air pressure underneath to keep it just a tenth of an inch off the ground. Perhaps adjust your weight balance as well, you might just be dragging on the ground too much. An ideal design can get around with little more than a leaf-blower as forward thrust, but who can get ideal without spending several digits....Awesome project, and with a few minor tweaks could perform like a dream come true. Well worth the money and time to try.

[Prometheus]

P.S. Added vote for book contest.

[carpe_noctem]

perhaps you could look into the jet engine instructable and fill the skirt using the exhaust( i know you should cool it down) and use tha actual drive(?) to power a fan or vice versa

[Kalianepic]

Great instructable! I have always wanted to make one of these. Do you think that I could scale it down to something slightly bigger than a skateboard? I can foresee some stability issues, but really nothing that couldn't be overcome with a gyroscopic stabilizer... Any thoughts?

[carpe_noctem]

i highly doubt their would be enough support now a surfboard, thats a different story. perhaps 60in long by 24in wide would be enough, just over twice average deck size.

[Prometheus]

Actually a surfboard was attempted on "MythBusters" (Discovery Channel), and was rather unwieldy. However, perhaps a design similar to hydrofoil boats could be applied with two of them and work quite well, but that also means double the thrust and even more than double the weight to support the two. To stabilize even a surfboard-sized hovercraft would take one heavy gyro, further reducing lift. An ideal shape is a "golden rectangle" (by the "Golden Mean" of a rectangle 13x21 or an equivalent L/W ratio of about 1.61904:1). Pythagoras had something right, even if he didn't fully understand it's remarkable scientific relevance. An aerial view of an actual military hovercraft shows how close to a golden rectangle it's footprint is, accounting for it's stability.

[carpe_noctem]

PS

SKATE AND/OR DESTROY!!!!!!!!!

[dbc1218]

Smaller can be done, check out universalhovercraft.com A gyroscopic stabilizer sounds a little over the top but if you want one do it.

[Darth_Reese]

The mithbusters made two hovercrafts.

[minerug]

The tv show "I didn't know that" made a hover craft with just a bit or plywood, plastics sheeting and a garden leaf blower. It still hovered when it had an adult on it. Nice work though

[1up]

Where did you get the horizontal shaft engine for the thrust? I've been wanting to make a go-kart and I need an engine with a horizontal shaft.

[TheMadScientist]

thats really excessive. the air cushon should have a far larger hole, or the back WILL drag.

[Thornburg]

Is it me or is Instructables featuring a lot of older Instructables. Like this one was posted in March of '06.

[Da_Fudge]

I was thinking the same thing.

[Thornburg]

Well it is kinda nice considering alot of them are pretty cool. I just thought I'd throw that out there.

[Da_Fudge]

I didn't mean that in a bad way, I was just saying. sorry if I caused any offense.

[Thornburg]

Oh no, just trying to clarify. Your fine.

[dbc1218]

I certainly appreciate it. This was one of the first 700 or so instructables posted and who knows how many there are now. I just found out the newsletter goes out to over 160,000 people so the site is definitely growing by leaps and bounds. I think the day of instructables being grouped with Google and YouTube is coming soon.

[Da_Fudge]

Whoa! First 700! That would've been a few years back!

[Thornburg]

That is really something to be proud of. I was here in late months of '06, just it wouldn't let me become a member (honestly). I just used a different email and it worked. Anyway good job.

[firestormcomputers]

does ur name happen to be kyle thornburg? and do you go to freedom high school?

[Thornburg]

No, where is Freedom High located. Never heard of it.

[firestormcomputers]

its in Loudoun County VA

[Thornburg]

I don't I live any near there, about a 820 miles away.

[GWJax]

I've seen a lot of homebuilt hover crafts over the years and with yours the few thinks I would change is putting a seat on it and a protective grill on the back of the main thrust blades so hair or other clothing would not get stuck in the blades, as is its a very dangerous setup but it looks really cool.

[Josh_B]

Took some filtering, but I finally found some used engines on eBay.

3HP Horizontal Engines
4HP Vertical Engines

[dbc1218]

Keep in mind my craft was fairly underpowered with these size engines. Check out universalhovercraft.com and the UH-10F for a 10hp single engine hovercraft design. I might try the UH-13P when ever I get the time and money.

[looking4ideas]

I made one using a shop vac I live near the coast so i want to make one that will work on deep water can some one test one out and msg me

[supersith22]

Very nice instructable, I once made one of these but it was round and had no motor on the back.

[I_am_Canadian]

I need a video.

[Joel D]

have you ever been sucked into the fan and then cut urself.

[Kendallkip]

have you?

[dbc1218]

No, I never got hurt riding this craft, but I could have. Looking back, this was the most dangerous thing I've ever built and had a very high potential to do some serious damage. IF ANYONE IS PLANNING TO BUILD ANY THING LIKE THIS PLEASE ADD PROPER GUARDING.

[finnster]

do you by any chance live in kalamazoo??????????

[Joel D]

i got my carcasses to power my fan from kalamazoo

[finnster]

becuase the church in the backroud looks like one near my house

[dbc1218]

never been to kalamazoo, I'm in ohio

[kington99]

Nice work, but you can significantly reduce the cost and complication by using a single engine and fan. I used to play with an old Formula 3 hovercraft, a racing class which stipulates single engine only. To gain lift, the craft had a scoop behind the rear fan that took a portion of the air exiting the fan down under the hull. The amount of lift could be fine tuned by altering the size/angle of this scoop. Just an idea that might help out other builders. Also you might like to put a guard over those fans, hit a bump, fall forward and you're going to lose an arm in your lift fan.

[the gizmoman]

you cac also use a leaf blower & pvc piping

[dbc1218]

yes you can check out xinventions.com

[A good name]

Me and my friends HAVE to build this!

[bayaan19]

what did you use to make sure your carborator is facig upward?

[fortneja]

Were you able to fly it enough to figure out a steering technique? I found that throwing your weight around helped cornering a lot, but my hovercraft takes a very delicate touch to maneuver properly. I've come very close to being thrown out of it before... Nice work though! Hopefully, I can get my hovercraft instructable uploaded soon.

[grayecastle]

how does it steer and how does the skirt work pm me

[dbc1218]

Thats a long and involved answer. Look through the steps again and search the comments for "skirt" and it should clear up some things.

[easyrider1]

you might try a blower from an old furnace for lift.go to a heating a/c repair place and tell them what your using it for and they'll probly give it to you.use stryrofoam on underside to make it bouyant(float).i saw the furnace blower thing sommewhere a few years ago,don't recall where though.i have a 16hp. 2cyl. elect.start motor just waiting around in my shed for a cool project.hmmmmm.

[AngusNotSoYoung]

This is such a great idea. A furnace fan would be stinkin great. And I wouldn't have to sacrifice my Leaf Blower or Shop vac. Thanks!

[Who Needs Brakes]

WOW thats awesome, Have you been watching MYTHBUSTERS or what ?? I seen them two make 2 Hovercrafts with leaf blowers & wernt they having fun on them lmao, good on ya mate well done

[dbc1218]

Actually the idea to build this came from another good show, Junkyard Wars. To bad its not on anymore.

[Choctaw]

I remember that episode, I think they had one made out of styrofoam they were on a beach or something. Didn't they also race them and one of the skirts ripped or something?

[lathmos]

I just saw that one, it is rerunning on the science channel at obscure hours...fine if you have Tivo though :P

[dbc1218]

I've seen it on weekends at 7am on the science channel

[tepse]

i loved that show man remember this guy named bowser or somthing

[jackaroo]

hello just like to point out that in cemting they use 2 4 bladed hovercrafts to evan out the cemt it sort of flys over it and i was wodaring if any one had any info for it

[AngusNotSoYoung]

They're not hovercrafts. The blades to spin like propellors but they do not push air. They simply spin and smooth out the mostly-cured concrete so you don't have to be out there with hand-trowels and knee-boards. There are two types. One that is similar to a push-mower and has a vertical shaft engine and a handle and you just wrestle the thing acrossed the concrete. The other has two spinning blades and you sit on top in the middle of them and you kind of steer around by changing the speeds of the sides, similar to the way a Dixion lawn mower steers. But i can see where you would get one of these confused with a hovercraft though. They're beastly.

[heavy.metal.nguyen]

Don't be mad but why do you comment on your own instructable? I think you need to put in more detail of all the wiring and motors.

[krish123]

plz give the blower and motor details

[PineapplebobTheGreat]

Uhhh... does this actually hover when someone is on it>

[Ryan G]

It is a great idea and I built three!!!

[hiker]

check out -fieldlines.com- and make your own prop.. its easyer than you think.....good luck.

[DeusXMachina]

A windmill runs at a few hundred RPM A lawn mower runs at a few thousand RPM..... I mean I have a steady hand, but I wouldn't want to be in the same room as testing a prop I made. Even if it doesn't destroy itself from the centripetal forces, it'll wobble the hell out of the craft

[ampSky]

WHAT? u made an instructable that turns out not to work?????!? thats horribly lame... so what would be a better engine if a lawn mower one doesn't provide enough lift? and does a lawn mower on work for the thrust fan? thanks for the idea though... oh does it work on water? that would be really cool!

[opiesan]

Actually, having it NOT work is probably more valuable than being successful on the first try. I've always learned way more from my mistakes than my successes. Congrats on making it as far as you did dbc.

[dbc1218]

heres my other horribly lame project, vacuum former It caught on fire during the first test run. I have had some successful projects just haven't posted them. At least now people know that they can't just go out to the garage and build a hovercraft on the scale. This craft will probably not be redone. If I do this again I'm buying good plans and building by the book. This was a great summer project and I learned a lot, more gained than lost. "Horribly Lame" is a little harsh but no hard feelings, you can't except great results, like going on water, with out a lot of work and and some failures along the way.

[Loveofchaos]

dbc, im planning on building a hovercraft, same size as yours. Ive already built 2 smaller ones before. their pics are on the forum for next full sized craft. when I start on my next one I Might have a few questions for you, would you help me out when I get started?

[skooterzkustoms]

cool Instructable. You should look at arrowprop.com they sell all kinds of props in many different sizes. otherwise good job keep it up.

[I can build it instead]

I like your Idea and spirit. I spent 20 yr. in the Navy working on Jet engines. I suspect that your fan blades are flattening out from the torque spin {centrifugal force} and decreasing your air flow. Also, think weight and balance, with the thrust system in place, was the back end dragging ? If your lift system was in the middle and your seat was placed such that the hovercraft back was a little bit heavier , then when you cut the thrust, air would spill out the front and help brake. Make slide rails for the seat and you can adjust W & B as needed. Stiff blades that flex only the amount you want while providing needed air flow can be made. The duct fan method helps prevent air spillage at the blade tips and allows supersonic tip speeds with less tip damage. Many years ago, Experimental Aircraft builders would make their own props. PM magazine had plans for a hovercraft with a lawnmower engine and homemade prop. Mount your throttle controls on a handlebar and hold on. You should go back and try again. Jon

[looseunit]

dame my sheds going to have about 50 half finshed project on the floor, keep up the good work

[9658469]

can u really ride this hovercraft

[dbc1218]

Yes I did actually ride this thing, to bad it didn't really go anywhere. The best part is I still have all my arms, legs, and head because this is probably the most dangerous thing I've ever built. If any one out there ever builds something like this please build it with safety in mind first.

[yrmoma]

I wonder if you could make this fan Collective Pitch, that way you could have a way to better control the speed as well as have reverse... Anyone ever try this or have an idea how feasible it would be?

[drink]

How were u able to control the speed?

[cspkumar]

You guys did a fantastic job. Don't give up and don't let negative comments distract you guys.

[X_D_3_M_1]

itd suck to have a fan chop ur head off

[Lftndbt]

Go the leaf blowers!! Already designed for maxmum air flow/power. A friend and myself built one of slightly larger size using two $50Au each blower vacs. One for the lift and the other for thrust/direction... The thrust blower was mounted 2 ft off the deck on a pivot joint allowing it to be swung around over head to slow the vehicle. It travelled well and built up a sufficient speed.. The air flow from the blower was sufficient that we were able to enter a water body at about 10mph with no more than a wobble.. Don't underestimate the power of a blower.. Another excellent reason for the blower is due to the enclosed unit, you can duct from the nozzle 100mm pvc pipe, then split it into two lines one for the front and one for the back of the platform... allows for a more stable ride...;p

[corester123]

oh yea and also try taking the governor off it might add enough power to get u to move. for extra hp mill about .003 in. off the heads :D

[corester123]

dbc i think u need a snowmobile 2-stroke thats what most racing hover crafts have, and possibly a more powerful lift like 5 or 6 hp. good luck :D

[quiksilver]

and put a grill on those fan blades if you treasure your appendages like I do.., great idea though!

[Nfiltr8]

chicken wire is perfect for that.

[Nfiltr8]

In order to have a duct that affects the air flow significantly, the margin between the fan and duct has to be under .25". You would have been better off putting the aluminum flashing on the inside of the duct's frame.

[ampSky]

another idea for stopping would be to turn off the trust fan and use flaps that are perpendicular to your movement, thus causing drag, the same idea behind a parachute on the back of a fast moving car. but i don't know how big they would have to be, or if it would even work. and the flaps would probably add a lot of weight so... probably not the best idea, but give it a try and let me know how it works.

[ampSky]

this may sound like a bit much but motorcycle engines are relatively light (being made of aluminum) and provide a MUCH greater amount of hp, and u can get them used for pretty cheap. so i figure i'll use one for lift and something really cheap for my trust fan. the whole idea for me was to be able to ride the hovercraft, and if it floats really high i might be able to mount my potato cannon onto it!!! thanks for the plans.

[the commentor]

Holy crap!

[dai3f20]

I've been toying with the idea of building a hovercraft for a while now and from all the plans I've seen, it seems to me that there's probably too much weight with both engines, the big fan, and you all on at the same time. Since there's less friction with it riding on a cushion of air, you wouldn't need much force to move the hovercraft forward, so why not use a leaf blower for your propulsion? It's be easy to steer just by turning the blower itself and would greatly reduce the weight. I like the idea of using a waterbed mattress for a skirt. My question is, how do you stop, besides the obvious running into something or wearing out the soles of your tennis shoes? I've thought about some kind of reverse flow cover like they use on airplane engines, but I'm not sure how effective that would be. Nice instructable, though. I would like to see an update with a working version. Keep working at it - it'll get there!

[dbc1218]

A leaf blower for the thrust could be very hard to do with this size craft. My craft did ride on a cushion of air the amount of friction with the ground was much higher then I excepted. The problem is the skirt dragging, If its to big the bottom edge will drag, so it has to match the weight of the craft fully loaded and match the power of the lift engine. It can be tricky to get right.
As far as stopping check out this company Neoteric They put big flaps on the sides of the duct that fold around to direct the air forward. In one of their pictures you can see them in action. If I build another I'll buy good plans and follow them to the T

[Greenlock]

From what I have ever learned your motors should be sufficient with proper blades and ducting. It would also help if you made the body more like an enclosed trapezoid. Another tip I picked up is if you can get a couple small electric motors and build scale models you can learn a lot for less.

[dbc1218]

My motors could work for this craft but I missed the mark on the propellers. Propellers have to match your motor to get the best efficiency. I did actually build a prototype with a large computer cooling fan and a similar skirt design. I under estimated the weight and power for the full scale though.

[ampSky]

hey dbc, nice craft... anyway, DOES THIS HOVERCRAFT FLOAT ABOVE WATER???

[the_burrito_master]

air conditioner motors would work good

[drink]

I have read this three times and i still dont understant the 8 parts of the skirt.

[dbc1218]

There are 4 pieces for the top section and 4 for the bottom section. the top and bottom are sewed together. Lots of people have had questions about the skirt, I'm going to get some better pictures of it so hopefully its easier to understand.

[Robert.Springer]

has anyone thought of the fan from a car would it work?

[instructing tables]

what about a giant windmill fan... would that work, that would produce alot of lift!!!

[marshall409]

are you thinking like a fan from the radiator? i was kinda thinking about that too. im having trouble finding props right now, so i havent started yet. i bought a cheap box fan from walmart, but the prop was way too flimsy and off balance so i took it back. anyone else know where you could get a cheap prop hat can move alot of air?

[Robert.Springer]

my friends father has an old lawnmower that we plan on using with a car radiator(not used to saying that) our thrust will probably be an oar as we plan on using it on a (slightly) tidal river. have u tried going the 2nd hand store etc and looking there?

[dbc1218]

You can get nice engine cooling fans from Advanced Auto Parts or AutoZone. They are about 20" in diameter and I think they look well suited for a lawn mower engine.

[Robert.Springer]

how do u connect them to tha shaft?

[dbc1218]

I would get one of these sprocket hubs http://www.mfgsupply.com/GoMiniSprocketsHubs.html/mv_session_id=hYjZADwR
to match the motors shaft size. Then drill holes in either the fan or the hub or both and bolt it on. Center it as best you can and it should be good.

[xNewkirAjx]

Great idea! I actually started one last summer, and am going to finish it this month (hopefully) I only need to find a mobile power supply instead of using an AC transformer and plugging it into wall power, like i have been doing. Oh yeah: did I mention that I am 13? xD not very difficult to build, really!

[the gizmoman]

try using a gas powered leaf blower

[brainiac]

hey me and my friends are working on a thing i call a hovering platform

[vince q]

you know those fans that inflate those large carnival things. how well would those work for lift?

[marshall409]

im so psyched im starting my hovercraft within the next few days, myabe as soon as tomorrow. it will be very similar to yours. however, the two engines i am planning on purchasing, the lift is a 6hp lawnmower engine...pretty big i think, not sure if its 2 or 4 stroke. lift engine: http://stcatharines.kijiji.ca/c-ViewAdLargeImage?AdId=14335715&img=http://kijiji.ebayimg.com/i20/03/k/000/77/5c/a7ac_18.JPG

the thrust engine is also 6hp, 4 stroke, horizontal shaft from a snow blower. i personally think that the power i get from these engines will make up for the weight of the two of them, plus hopefully upwards of 300 pounds payload. i may post an instructable when im done, or i may start a weblog so i dont have to wait til im finished. wish me luck!

[thecheatscalc]

Ahh, good to see another hovercraft! I've made one myself (about the same price) same size... cost under $200 too! Must admit I never got around to producing a thrust fan... Ah, good memories.... one thing I'd suggest though, is instead of using plastic, go to the local arts and crafts (fabric) dealer, and pick up some rubber backed nylon. I had some of the stuff and tried to rip it on the corner of a brick... took me a few minutes! VERY VERY durable stuff, plastic never would've made it! Anywho, makes the skirt a bit more durable. You've also gotta make sure that those corners don't drag... then again, you do seem to have a different type of skirt then I did... hmm... I went for the more complicated bag skirt... nevertheless, GREAT job! the design seems to resemble my original plans I got at www.xinventions.com too bad I didn't even follow the plans... the only similarity was the dimensions of the body!

[Spl1nt3rC3ll]

I just posted a instructable on how to make a simple, rideable, hovercraft with a shopvac engien. it can hold up to two adults. yours is a bit more complicated and is also very cool with a more powerfull lift and thrust. great job on it, check out mine and give friendly comparisons.

[ninjaman]

I just saw your hovercraft design and I know I've seen a hovercraft simpler than yours. Go to YouTube and look for Kodirat's Homemade Hovercraft video. It's pretty cool.

[Spl1nt3rC3ll]

Hmm, That looks to be almost the same hovercraft design, only he used a leaf blower (which is more powerfull then the shop vac), a square board, and there's no thrust fan. You are talking about the vid with the Austin Powers "It's a hard life" in the background right? It is cool though, If I've seen the right one, add a link.

[Spl1nt3rC3ll]

And there probably is a simpler design out there.

[ninjaman]

Yeah, that's my friend and his cousins in the video. I was telling him to post an instructable on it, but I see the idea's already been taken...

[Spl1nt3rC3ll]

Aww... did I take it first? I'm sorry. At least your friend has his on youtube. If he did post an instructable it would show the difference between Shopvac and leaf blower and how the shape effects the hovercraft. Go ahead and post it, I don't care. :)

[Red_Impact]

its realy nice one but if u just want 1 cheep use leaf blower and sum 6mil plastic and a staple gun and sum holes on sum plywood

[Loveofchaos]

Very nice work, i hope to make one later, well when i have the time money and skilzzz.....~~~Derek~~~PYRO~~~

[bigcountry932]

i have one more question...how big was the thrust fan u used in the rear? thankyou, Tyler

[Spl1nt3rC3ll]

mine would be easy for a science fair.

[bigcountry932]

hey i like ur idea and i was gunna try it but i have a question about the skirt how deep is it overall from the ground to the craft? thankyou

[dbc1218]

When it was hovering there was about a 4-6in gap between the ground and the bottom of the craft.

[Burn]

Hey, I really like your idea. Can you send me more detailed plans. I would really appreciate it. -Thanks Derek Baltazar

[Assassin]

Hello Burn, these plans have been copied off a site known as http://www.xinventions.com/xinventions.htm

Please email them if any questions,

regards, Jack (aka, Assassin)

[dbc1218]

While our designs are simalar I did not copy his craft. He has plans that you can buy but I never bought them. Also if you look at the builders showcase on xinventions you'll find my hovercraft. If you bought his plans then ask him, but I might be able to answer more general questions.

[dbc1218]

Like I said to JCorlin, I don't have any real plans. If you have any specific questions though, I might be able to answer them.

[andy-b]

New group about hovercrafts:Hover-Carfts

[casvandegoor]

this is amazing!

[grenades_and_ham]

i understand how the skirt that runs over the bottom and then you cut holes into. i did that for my first small hovercraft. but did you bolt part of the skirt to the perimeter of your hover craft, and fold the skirt under and then bolt it? thats what i am confused about. or is it just the top is sewed together and the bottom is loose but the inside layer is shorter than the outside? thats how i understand it

[dbc1218]

There is only one layer, with the top part connected to the perimeter and the bottom haning loose but held in place with a thin ropes. The ropes are attached to the bottom edge of the skirt and then to the bottom side of the craft. This keeps the skirt from blowing out the side when hovering. There is no inside layer and no holes in any part of my skirt. This is just one design though, there are many different skirt designs out there.

[wgpshadow]

How many holes did you put in your skirt for air flowing out?

[dbc1218]

In my post just above this I said there are no holes in the skirt and in the post just below this I explained why.

[Sanil]

hey i think i am posting a comment pretty late but i am making a hovercraft for my project at college, i am making a craft of size 8x4 feet. using a single engine which would drive the thrust and lift fan, i would like to know your design of the hull, my email address is [e-mail] , so if you can help please mail in to me

[dbc1218]

The hull is simply two pieces of 1/4" thick plywood with a 2" thick sheet of Styrofoam sandwhiched inbetween, thats it. I'm sure there are better designs out there so If I were you I'd do some research. I've said this before but if your building a hovercraft for the first time get some plans or at least build a small prototype to check out your ideas. Trust me you will save a lot of time and effort.

[CommanderFlint]

I like your design and I'm trying to make a hovercraft myself (just started and so was looking around to see who else made one). I was wondering, when you say use a more powerful motor, do you mean a lift engine, thrust, or both? I have an old snowblower 4.5hp engine, you think that would do for a lift engine? I'm thinking of making a hovercraft that can hold two people, so it will probably be about 12x5 or so (I looked on universal hovercrafts and they have one, the explorer, which i think most fits my description). Tell me what you think.

[CommanderFlint]

Ok, I will try that, thanks for your help.

[dbc1218]

If your building it your self and this is the first time you've a havercraft I would recommend that you get a set of plans. Build it by the plans a learn how everything works and why everything was done the way its was. Then you can go back and try to make it into something you want. Trust me here just get a working craft first and then do whatever you want to it.

[JCorlin]

we are trying to make one like yours can you e mail me blueprints to [e-mail]

[dbc1218]

I don't really have any blueprints for this craft, I just sort of built it with what i had and what I knew I wanted. You could look at the DWG's on the skirt but thats the best I have. If you want some real plans google "universal hovercraft" they have some great prints for all different size hovercraft.

[Scubamatt]

When I was a kid we got an old water bed liner and blew it up with air and had big fun. I bet this would make great skirt material because it is so tough, good luck this is a cool project!

[grenades_and_ham]

hey i have a question how exactly is the skirt inflated is it like an innertube and the deck sits on top of it. or just like a sheet of plastic that surrounds the whole perimiter and the fan inflates the chamber. more detail onthe skirt would be a ppreciated.

[dbc1218]

The skirt is just a sheet of plastic along the perimeter of the craft. Its designed to hold the air under the craft and not let it escape out the sides. The skirt is not air thight its only function is to hold a cushion of air under the craft and as pressure builds, because of the lift fan pushing more air in, the craft will lift off the ground. You might ask, How does the air pressure increase if the skirt is not air thight? Well the skirt does allow some air to escape but not so much that the presure can't get high enough the lift the craft. In the case of my hovercraft this small amount of air escaped between the bottom side of the skirt and the ground. With other skirt designs the skirt is sealed to the bottom of the craft and holes are cut in the interior part of skirt which allows the air to escape under the skirt as well. The small amount of air flowing between the skirt and the ground is what makes it a hovercraft, because essentially the skirt is not touching the ground either.

[grenades_and_ham]

hey i have a question how exactly is the skirt inflated is it like an innertube and the deck sits on top of it. or just like a sheet of plastic that surrounds the whole perimiter and the fan inflates the chamber. more detail onthe skirt would be a ppreciated

[joen9]

Hi. I'm building a hovercraft for my science fair project. This is a lot of help, and i have a few questions. What type of fans would i use for the thrust and lift, and where can i get them? Also, can the engine power vary using these instructions, and if so by how much?

[dbc1218]

Before I can answer these guestions I need to know more about your craft. How large, how much weight, your budget, using two motors or just one? These are just a few of the thing that need to be considered. If its for a science fair project I would go with something smaller. There a plans all over the internet for havoercraft powered by leafblowers or shop-vacs, this would be a good place to start. I know thats not very flashy but what If you built something simple and then came up with new design and then reported your findings on your new idea, That would really impress the judges.

[cbetts07]

awesome, thanks a ton. [e-mail]

[cbetts07]

Im beginning to understand a bit i think. so one end of the material is attached between the plywood and styrofoam around the base of the craft. What do you do then with the other end of the material? does it just hang straight down, or does it get attached to the bottom side of the craft? Ive read that there is a "full flow bag skirt" and a "no flow bag skirt" both of which make it sound like the skirt and pocket of air under the craft are two separate things that need air to be blown into them. does your lift fan blow all of the air into the skirt, and then the skirt leaks some of that air into the middle, where the air pocket is, and from there it leaks out underneath the craft creating the clearance? am I even on the right track here? dbc1218, if you wouldnt mind, could i get your email so i could shoot you some other questions if you wouldnt mind helping me out a bit. thanks again

[dbc1218]

I had these same questions too, while I was building this hovercraft. Post your email and we can start from there.

[cbetts07]

This has been one of the most helpful things ive seen. Im working with a group for a class and we're building a hovercraft. I have an old lawnmower engine that we'll use for the lift. The main problem i'm having right now is understanding how the skirt attaches to the hull. Is the lift fan on this hovercraft blowing into the skirt, or is the skirt pre-inflated? any help on these things would be awesome, thanks

[dbc1218]

The skirt is sandwiched in between the top piece of plywood and the layer of styrofoam. Where the bolts went through the base, and through the skirt, I put brass gromets on the skirt to help strenghen it. Also the lift fan blows into the skirt and fills it with air. The skirt cannot be pre-inflated because its not air tight. The skirt is not like an air tight bag that sits under the craft, its more like a flap around the perimeter of the craft designed to hold the air under the base and not let it excape out the sides.

[TheMadScientist]

anyone know if coating the outside of the airtight skirt with something like... denim would help increase durablility in case of hitting or rubbing against something?

[TheMadScientist]

know where i can get an inflatable raft? if so, i'l test it out... i'd probably have to trim it up a bit though

[ArmChairQB]

I wonder if you could make the skirt out of an inflatable raft? Might make some sort of concave super structure to reduce the volume a bit and force the air down.

[Ian01]

Easier, safer hovercraft

[skautistic]

Easier...Yes Safer...Yes Better...No

[skautistic]

Amazing, you put far more effort into your Instructable than most do.

[brandor]

Wow, nice job!

How did you prevent the skirt from bulging out on the sides? <A HREF="http://img252.imageshack.us/img252/9346/1212126imgbm2.jpg">My hovercraft</A> has real problems with that; I had to have a network of strings underneath to make the skirt keep its shape.

(Also, I have no couling, so the thrust fan does both diddly and squat...)

[dbc1218]

Fist off, your craft looks great, a lot cleaner than mine. As far as the skirt it actually does not have any strings from the bottom of the skirt to the craft. On my skirt there is a flap on the bottom that I folder over and sewed up so there are 4 pockets around the entire perimeter on the bottom edge. Then I put 4 pieces of flat wood into the 4 pockets, the length of each side, and connected them at the corners. This held the skirt in place and I never had a problem with it bulging. This was my own design and because the craft never really moved, I’ve never really tested it out. I know that using string to hold the skirt is fairly common but I don’t know much about skirt design. I just had the idea and went with it.

[vonage]

I made one of these back in 6th grade. Mine was circular. We used a gas leafblower. But we didnt have a drive fan so you had to get pushed or whatnot. It was a fun project and didnt take but about 2 hours to do it.

[dangoss]

help me with this plz so i can buld 1 ta an wt can u email it to [e-mail]

[robotix]

Yhea what do you want to know?

[dbc1218]

What exactly do you want to know?

[robotix]

I've made a hovercraft and I still have it it is the trangle shape one and it uses an electric leaf blower. I'm thinking of puting a gas powered leaf blower on it so I can drive it around town and stuff.

[alewis92]

I just got this brand new 25cc leaf blower for $50 and I am really thinking of making a hovercraft. Where do you get painters sheet? I cant find any at my local hardware store. Do they have it at home depot? thanks andrew

[dbc1218]

Yes they have it at Home Depot, thats were I got it. Its in the paint section, but if you can't find it just ask someone. I think I got the 6mil thickness.

[dbc1218]

First I want thank everyone for the great suggestions and support for this project. I don’t think I will be putting this thing back together any time soon though. I needed the lift engine back so I could mow the lawn and I want to build I mini bike with the thrust engine. I have looked into building a hoverboard and if I ever get around to it I’ll be sure to put it on the site with more complete instructions. Thanks

[got_ya]

Awsome job guys two things tho the rear engine could be smaller if u made umm Bugger the name escapes me for now but its like a shell to fully direct the air in a striagt line instead of wasting power with the air going out sidewards more and i has to be much longer and this will give better steering and better contcenation of air flow and secondly power over kill smaller engines equal less weight but less power but u dont need the extra power coz the less wieght duh Yer but great try (sorry bout the spelling)

[alewis92]

this is so cool. I have an idea to make it work (hover). Take out your whole lift fan assembly and build a box around the hole out of lauan(that isnt spelled right). next buy 2 cheapo leaf blowers and cut the nozzles off. cut holes in one end of the box the same size as them aned calk them in(thats the maine way of building, if its broke, put more glue on it) this should work and lift your whole thing up. if you have to counter the weight, run some pvc pipe to the need areas from the box and plug up the bottom hole. andrew the cool

[hoverlord7]

Outstanding for a first try. The weight issue isn't the concern it may seem. I've been building heavier than normal hovercrafts all my life. You must have the lift fan turning at RPMS hihgher than you might expect. Crank that engine to it's max. And there can only be the smallest gap between the fan the duct wall. There should be no room for air to come back out that duct. The angle and type of fans are crucial as well. (Search on the net for hovercraft props). Also... check for leaking of air from your bag skirt. None can escape out of holes, rips, etc. If you use materials that make it too light, it won't last but an hour or more. Work on the crafts efficiency.. and not so much it's weight. Hovercrafts only operate well in the last 10% of the power curve. Take away anything that makes it less efficient and they barely work at all. Keep going.... you'll be rewarded with one of the most fun rides you'll ever experience.

[vansea4]

Sounds like you are the pro around this subject. I'm trying to figure out a couple of things for my own craft. Can you use a single fan on a hovercraft or will it spin out of control? Some of the designs I have seen all seem too overpowered for my ideas. Can you suggest an RPM minimum to lift a total weight of 300 lbs (craft and person)?

[Hugo.B]

Please, please, say hovercraft, not "hovercrafts" . Have you ever heard anyone say "aircrafts"? Anyway, It's a great project, one that I have been meaning to do for a long time.

[Hendrix67]

How thick was the wood? maybe if you used a thinner wood and some foam as a second layer it might be considerably(think i spelled that right) lighter.

[spedie08]

most of your weight is coming from those massive engines. those engines are way over powered and were designed for mid rpm, higher torque purposes. for just the use of spinning a propeller (or fan) a lightweight 2 stroke engine would be best, and they can run at high rpms for a long time just a thought....great job

[PeterTheUnGreat]

On 'Scrapheap chalenge' (a.k.a. 'Junkyard Wars' in USA) they built a similar hovercraft but used a sheet of 50mm polstyrene loft insulation as the baseboard - if you did this with a couple of timber rails to mount the engine on you could loose a lot of weight Pete

[radiorental]

Ok, so its a little heavy but bloomin excellent first atempt. How about next year they design and build a remote control for it? If its still too heavy you could cheet a little with some spring loaded rollers underneath.. would allow it to cover varied terrain. I think this is still very salvageable. Excellent project.. another prize winner I think!

[radiorental]

oh, please put a grille over the drive fan... (o;

[dbc1218]

Yes I know this craft is not very safe, its probably the most unsafe thing I have ever built, but as of right now its dismantled. I still have everything though so if I ever try to put it back together, safety will be number one. I’ve realized now after building it how important this is.

[geekxx]

I suspect you might overcome the weight problem by using a more efficient lift propeller. Like something from here: http://www.tn-prop.com/forsale.htm