We are building a hovercraft!

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GOOD DAY! My name is Nathan and I am posting this here hoping that if I am about to die somebody will frantically email me and tell me about it!!! :) Thanks.

So we are going to build this thing and race it in the annual drunk hics floating down a river competition (not actually what it is called but it is suiting). We will totally be disqualified but that doesn't matter, we were going to just kinda start building and hope it works out like last year when we made our raft out of a steel bathtub. WHAT ARE the safety precautions for us to look into?? Is the thing going to flip over if we don't know what we are doing??? how long does a lawnmower engine last on a tank of fuel?

All of that keeping in mind that last year our budget included Duct Tape and some rope... What should be make the skirt out of?

-- Nathan Lunde-Berry (nathanlb@home.com), January 20, 2001


I can see a "raft" of hovercraft being built as a result of this show! It is something that I've always wanted to build, but this show seemed to make it simple!

The skirt needs to be made of something abrasion resistant that will hold air fairly well. Light weight is a consideration as well. One of the teams used an old army tent. I'm not sure about the other.

I would expect the hardest things to find would be props and a shroud. Most of us don't have access to a jet engine shroud!

As far as safety goes, some basic rules that apply to many machines that go on water:

Cover all spinning parts: Amputations aren't a desirable result.

Positive Bouyancy: You hope to float above the water, but when the engine quits, make sure the whole thing doesn't sink to the bottom! I expect the Long brother's styrofoam would have floated even with the engine and driver. Keeping upright is another matter. I believe commercial hovercraft achieve this by keeping the bouyant part around the outer edge.

Standard boating rules: Life jackets, paddles, etc.

Good luck!

-- Michael (Canadian P. Eng.) (michael@mks-tech.com), January 20, 2001.

I haven't built one yet but plan on using a painters drop clothe. You need to get the commercial style cloth which is butyl coated canvas. They are listed as abrasion resitant, they are cheap and light weight.

-- b dudley (bdcd@bellsouth.net), January 20, 2001.

as far as a shroud...do a search for 'hovercraft', and even visit www.hovercraft.com . There is a technique of cutting some 36" disks of plywood, using a piece of pipe, and bending some 3/4" foam around it (gluing using the foam-in-a-can), and then 'lathing' the result.

you can get plans for a variety of models.

-- Mighty Mik (mightymik2@home.com), January 20, 2001.

quite an undertaking! as for your inquiry on the skirt material....used conveyor belt is an incredibly stout material, and i dont belive you can hurt it!...i think the wicth of it is about either 24 or 36 inches....you can find this at your local gravel quarry or cement truck supplly company

-- tim (milehiharley@hotmail.com), January 21, 2001.

Dear Nathan, I see you have gotten some REALLY BAD advice here LOL. Tim; conveyor belting ??????? Have you ever picked that shit up it weighs a ton. Your machine would have to have a jet engine to get off the ground . (ROFLMAO)The painters drop cloth might work but doesn't sound strong enough to me. But, what would work nicely is an old slightly leaky rubber boat (the canvas ones not plastic), just remove the ore locks & seats by cutting them off without damaging the air holding abilities of the boat. Small leaks are ok. Now turn boat upside down. Build a light platform on it. Use a fan with a shroud & duct about half the air into the boat air chambers, by cutting a hole in it below the motor(most rubber boats have two chambers so by cutting a hole in the middle & taking out the partition it makes one chamber. Cut an X to make the hole in the boat so you can use the flaps to secure to the fan shroud . Pop rivet it to the fan shroud & seal with silicone. Then cut some holes about 10 of them near the upper inside of the chambers & cut in a V (Pointy end down)pattern about 2" long for the air to escape into the center of the boat making it hover. If it is to firm ( it should be a little squishy) cut the holes a little bigger. Then adjust the ducting till it hovers nicely at a high idle (so at slow idle it will set down) A 10 h.p motor & about an 18" to 24" prop will get ya flying. Use some 6" or so Styrofoam on the bottom of your platform (inside the boat) to make it float, if you go on water & it gives it something to sit on at an off idle & so it doesn't collapse the boat flat.

"Rick The Rocket" future Junkyard Wars contestant.

-- Rick Lawrence (hoodoo2@povn.com), January 21, 2001.

Hey there! :) Thanks for the advice thusfar guys.

I would like to know what the chances are of the thing completely flipping-over??? how would I go about making this happen because I really don't want it to.

As well - what are the advantages of a light craft as opposed to a heavier one? Two motors or one motor? There will be four of us on the raft, and would like an old FAN work to push us along? Thanks again for any more input you can dish on over to us! :)

-- Nathan LB (nathanlb@home.com), January 21, 2001.

You would need a large craft with a huge motor for 4 people The rubber boat craft is only good for about 250lbs. You NOT gonna do it with no lawn mower engine. More like a 302 ford V8 LOL

-- Rick Lawrence (hoodoo2@povn.com), January 21, 2001.

We're planning on using a skidder inner tube covered with a non abrasive material. We are thinking of using a lawnmower engine to drive a turbine on the bottom and keeping the tube fully inflated. If the tube needs to have air moving in and out then we will cut holes on the inside ring and use a leaf blower to continually pump in air. As for bringing four people, it is a stupid idea. The craft will be very unstable and and weight changes could result in the capsizing of your craft. dont expect to lift four people, 1 will be challenging enough. GOod Luck

-- fsdf (dfgsd@adf.com), March 07, 2001.

I plan to use old inner tubes for the skirt on mine. They are pretty heavy duty, can be sewn and patched fairly easily are not too heavy. Old tractor tubes are a good size and would not require too many seams to be sewn depending on the size of the craft.

-- Tim Pickles (tpickles@citllink.net), March 21, 2002.

I had the wrong e-mail address in my previous answer!!

-- Tim Pickles (tpickles@citlink.net), March 21, 2002.

im building a hovercraft and what i was thinking for a thrust duct was using a old clothes dryer tube [the chamber that holds the clothes] some of them you can remove the parts that stick out and turn the clothes over. i dont know where can find a cheap fan but do know where you can buy one.look up www.multiwing.com

-- lj (lj_j_2001@yahoo.com), April 17, 2002.

im sorry, the adress that i gave you was wrong, its www.multi-wing.com it needed a dash.

-- lj (lj_j_2001@yahoo.com), April 17, 2002.

i really need some plans for a foam hovercraft if any one can help please email me. needs to hold 3 to 4 people. thank you

-- sarah hardwick (serzhardy@hotmail.com), September 20, 2003.

i tried to build a hover craft witha 5 hp brigs and stratin and used a air condinor blade and fire hose for skirt it didn't work cause i couldn't make a good fan housing i don't kno what to make a fan housing out of could some one help me email me with some better plans

-- KT (spitfire84@comcast.net), October 17, 2003.

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