Low flying foamy (Hovercraft)

[hcopter]

After dusting off my 2yr old, scratch built, hovercraft last week and flipping it over and breaking it I got inspired to make a new improved fanfold hovercraft. After several days of improving my minimal AutoCAD skills, a few prototype versions and many tweaks and changes I now have a nice, new, laser cut hovercraft.

I drew up a couple of sizes, one for a 6 inch prop (9"x13" base) and one for an 8 inch prop (11"x15"). The motor mount is cut for a standard GWS IPS mount but any motor could easily be mounted. The skirt is a simple design using thin plastic such as a grocery bag or trash bag or something more durable such as Tyvek would work well also.

If there is interest I could probably offer a short kit of laser cut parts.

I also have a short video that I will try posting.

Also, the final version has much larger front fins to improve turning at higher speeds Vs sliding into things. :)

Mike

[challenger_i]

Me LIKEY!!!!

So, if a man were to use a Speed 600 and Olympus drive, how large would it be?

[ScienceGuy]

Mike,

Is this a 2 channel unit? It looks like power and rudder with lift derived from a portion of the prop wash being deflected down under. I bet that of my flyers would love to build a couple of these to race in the gym.

Can't wait to see the video.

Hugh
Newark Electric Flyers
Newark High School

[hcopter]

Hopefully this will take you to the video:

http://www.rcgroups.com/gallery/showphoto.php?photo=15792&sort=1&cat=500&page=1


challenger_i,

As long as you used an 8" prop, same size, but very hard to keep right side up :D

[hcopter]

Yes, it's just two channels, but I'm already modding mine to make the front fins steerable for Xtreme driving action. :)

I will post a few close up shots later tonight showing the air bag etc.

[ScienceGuy]

Mike,

Both my wife and I teach high school science. We think that the general hovercraft concept would make for a great competition project for high school or even middle school tech students. By using inexpensive radios, servos and fanfold the costs could be kept to a minimum while the fun factor should be fantastic. Either pylon or grand prix style races would very simple to set up with a few orange safety cones and design/build competions could be run over reasonable periods of time.

We're excited,

Hugh

[Rocketman1092]

I have a couple store bought plastic hovercrafts. They work well on water, too. There are 2 motors for drive and 1 for lift on each.

[Matt Dziubinski]

crazy design, i like it!..nice job...is that just an ips motor running it all?..yes looks like it is, try throwing a fieago in there..would rock!..what battery?

[challenger_i]

ScienceGuy: Contemplate load-lifting contests, and egg races. Just a thought.

[challenger_i]

No doubt, that a Speed 600 and 2.3:1 drive would make a radical machine out of it. Was curious, as to how much LARGER a machine could be made, on the same lines (I love your concept!), using 250 watts.

[hcopter]

Hugh,

I work in the college of technology at a university and a few of the instructors here are wanting to incorporate more R/C stuff as well. I provide them with new ideas and drawings in exchange for some laser cutter time. :)

Duber,
Yes, currently GWS S1 IPS. But will probably be a CD-ROM by the weekend, mainly to make it quiet. I have been running two and three cell Li-po and Li-on I have a 2200 Mah 2 cell Li-on that's too heavy for a plane but will run this thing for a looong time.

challenger_i,
It could probably be scaled up to around 15"x24" before it started getting too flexible. However you could use thicker foam and or additional structural parts to overcome that. I can only cut up to 12"x24" on this laser though.

Mike

[SaMx]

cool, I had an idea for someting like this for this winter(on the snow), but didn't have the stuff to do it. are you useing a skirt on your hovercraft or is it just flat. if it's just flat, I would try adding a border of foam along the bottom to make more. of an air cushion.

[Rocketman1092]

It looks like there's a skirt there.

[hcopter]

Here are a few more pictures showing more detail and the smaller version as well. The larger one shown here is slightly longer than the final design at 18x12 vs 15x11

You'll notice the battery placed to the right side, this is to offset motor torque so it rides more level. Front to back battery placement will adjust fore-aft ride height and how fast you can go before the nose starts to lift off the ground. It will go fast enough to catch air and flip over backwards or to the inside of a turn.

[KsFlyer]

Nice. It's been a while since I have driven the hovercraft :D I think I actually gave mine away to a highschool kid when we were flying Mike. This design is much better and a cooler design than before. Nice ship Mike.

Troy

[10Thumbs]

Hmm, an EDF unit for drive would be interesting, and be safer if you have inexperienced users. Would give you less thrust for the input power, but it probably would do the job.

[Ralphw]

Hmmm..I'm thinking of a CPU cooling fan running at a fixed speed as the lifting fan (I have several) and my old GWS motor to propel it. I like it :D...something fun to charge around the field with between flights!!

[ScienceGuy]

Mike,

When we have build personal hovercraft for physics, (they carry one person), we have used a skirt that covered the whole bottom of the craft but had a series of 1" diameter holes covering the whole botom that disperse the pressurized air more evenly. This change in the skirt might provide an improvement in the levelness of the levitation. Perhaps this isn't a problem but it looks as if the skirt extend so far tword the center of the craft that it would be unstable.

Just thinking....better start cutting.......testing....changing.......

Thanks for the food for thought

Hugh

[meowmix]

What about a foam skirt? Harder to make and replace, but if you used the holes as ScienceGuy mentioned, it should work quite well. And if it were angeled out at the ends, you could create some really nice stability.

[hcopter]

I've seen the skirts with multiple small holes in them but haven't tried one on this yet. The first one I built 2 years ago got a lot of run time on it with the original Walmart bag skirt and it worked well enough I never spent the time to try any others.

You can see in the video that when this one is at high power and the skirt at maximum inflation that it does rock around a bit.

Meowmix,
What kind of foam are you thinking about? It would need to be something flexable that won't snag on edges etc.

Mike

[aV8ter]

I'll buy one! Sign me up. How much will it cost? I think a hyper drive prop would produce more lift, and would work better in reverse.

[ozace]

Plans would be great depron hovercraft sounds like fun, and a great way to use the brushed motors laying around.

Nice project.

[Daddy-O]

I may be interested in one of these if it wasn't too pricey. There is no such thing as carpeted floors down here where we live and this would be a lot of fun anywhere we went!
Daddy-O

[hcopter]

I'm thinking $18 shipped to you door (48 states), choice of two sizes for 6" or 8" prop, and $5 for AutoCAD and PDF drawings emailed to you. I am taking a few kits to the KC indoor fly tomorrow http://www.kcflyingcircuits.com/miff.htm


AV8ter,
Do you have a reversible speed control? That would be handy on this to backup away from the wall when it gets stuck :)

Mike

[ozace]

since i am in australia the plans will be great, let us know when and how

adam

[aV8ter]

I do have a micro car speed control that would be perfect, the only problem is, is that your design uses prop wash to creat lift, thus you would not be able to move.
I will still buy one and put a seperate fan on it for lift.

Kevin

[meowmix]

When I said make a foam skirt, just take a 1 inch strip of 1mm Depron and wrap it around the side. Then, attach another piece on the bottom with holes in it. Could work pretty well...
I just started my hover craft. It's 10x16 and powered by an EDF 40. If it doesn't work out, I'm going to mount my second EDF 40 for lift. It's going to have a single rear rudder in t-tail fasion with a spoiler on top. It is also going to have twin forward rudders with a spoiler on top.

[hcopter]

I am waiting on some boxes large enough to ship the larger sized hovercrafts in, hopefully sometime this coming week. I can ship the smaller ones immediately and I also have the drawings ready to email , the drawings include three different sizes.

The kits are a "short kit" of just the laser cut pieces ready to glue together and add your radio gear/motor.

To order please PM me for paypal payment details. I can only accept non-credit card funded Paypal since I just have the basic account.

Thanks for the interest,
Mike

As a side note, I got to run mine at the KC indorr fly today and found that the steerable front fins do not add much to the control and are probably not worth the extra servo and linkage etc. I also put on one of my extra CD-ROM motors with an 8x4 HD prop on three cells, waay overpowered :) . Anything over half throttle and it wanted to go airborne

[meowmix]

hehe, airborn might not be a bad thing... It'd be pretty cool to do short hops and stuff. :p

[aV8ter]

Could I be a beta builder on a larger vesrion? Please!


Kevin

[hcopter]

Sorry AV8ter, not looking for any beta builders. Also, I can't make them any bigger due to the size of the laser cutter.

[TimAidley]

This thread inspired me to have a little play at the weekend:
http://www.planettimmy.com/albums/hovercraft/Gabriel_001.thumb.jpg
(click for bigger pictures and a movie) (http://www.planettimmy.com/gallery/hovercraft)

It's built from a Crunchy Nut Cornflakes box and a Woolworths carrier bag, plus some of the bits from my old Graupner Tipsy (now .. ahh... 'retired').

Fun and very quick and easy to build ;-)

Doesn't turn that well though...!

[hcopter]

TimAidley,

Nice use of available materials :)

Looks like it works ok, you need some fins up front to help with turning, and a larger area to run it in :)

Mike

[TimAidley]

TimAidley,
Nice use of available materials :)

Thanks!

Looks like it works ok, you need some fins up front to help with turning, and a larger area to run it in :)

Ahhh.. Do they help to stop it sliding sideways?

Edit: Oh whoops - I see what you mean now - more moving fins.

[hcopter]

The front fins don't need to move, I found that didn't help much, but they do need to be there to provide some surface area so when it starts to slide sideways the front will "stick" and let the back come around in the turn.

[Steve-S63]

I'm building one with dual EDP 50's for power. 1 for lift & one for thrust. I have 2 ISC 50 ESC's and am wondering how I can get differential throttle control, via flaps dial for lift fan, with ony 1 battery. Is that possible? If so how would I go about wiring the ESC's & motors? I'm not using a skirt on mine just a foam plate with alot of 1/2" holes in it. It lifted ok without the 2nd motor, fins or servo. Lift motor has a 3x3 prop and thrust will have a 3x2 as I only had 1 3x3 that would fit the shaft.

Thanks in advance for any help.
Steve-S

[hcopter]

To wire the two esc's you just need to make up a Y cable that plugs into the battery and to both esc's then plug one esc into the throttle channel and the other into the flap channel. I have done this on several twin airplanes where I used the rudder channel for the second esc then mixed the rudder and throttle together for differential thrust without a movable rudder, works good.

Hope that helps,

Mike

[Steve-S63]

Helps alot. With an EDP 50 @ 3x2 this thing will haul pretty good. Doesn't get very high off the ground though, about 1/4" or so. I had to take the 3x3 off the lift motor as it started smelling kinda funny. :p Now to build a skirt to see how much improvement it provides. I'm having trouble with balance and torque though. It wants to drift to the side and spin some. I tried cutting 2 holes in the sides, one at right front and one at left rear, to counter the torque but now with the 3x2 it's spinning the other direction (not the motor, the craft). :confused: I also have to cut down the verticals in front as it turns at the drop of a hat if it's not perfectly into the wind. Still fun to play with in the kitchen, my cat hates it. :D

[rweatherly]

I want to build one with a lift motor and a thrust motor, but would like to have a set speed for the lift motor and variable for the thrust. Is there any easy way to control the lift motor speed so you don't have to have an ESC for it?

Thanks,

Richard

[pimp_squeak]

I want to build one with a lift motor and a thrust motor, but would like to have a set speed for the lift motor and variable for the thrust. Is there any easy way to control the lift motor speed so you don't have to have an ESC for it?

Thanks,

Richard

run the lift fan directly from a seperate battery with a switch inline or something, turn on RX< then turn on the lift fan and you're ready to go...

[hcopter]

Ok, my boxes arrived so I can now ship the larger 15" hovercrafts. I still have 4 of the smaller 13" ones available.

$18 shipped to 48 states, priority mail with tracking. Or get the CAD drawings for $5.

You can paypal or email me at ylf@cox.net

Thanks,
Mike

[experimental_pil]

Have you done any tests on water?

[hcopter]

Haven't tried it on water yet, I didn't really design it for water, I mainly run it inside at our indoor flying sessions. I originally posted this in the foamy flying section and the moderator moved it to the Boats section. Maybe it would do better in the indoor section.

Mike

[BartMan]

Finally something right up my alley. I've been making hovercrafts for a few months, got the info from several web sites for Large and Micro (4"x3"). I have alot of fun with the hover crafts. My large is 24" X 18" with a EDF 75 lift motor direct from a Ni-cad and a pair of 400's for thrust and dual fins for turning, always wanted to make it differential thrust steering. Used a Rain pouncho for creating skirt and has an AirBox to spread lift into both the skirt and lift. It's currently too heavy as I used 1/8" Hard board for the main base and lift box. Looking to redesign in the next few months. Micros on the other had are something I picked up from the other RC board in MicroFlight by a guy with the handle of Tim the Tool Man. Used a Meat tray foam cut to the 4"x3" size, seperate lift motor from a RadioShack Zip-Zap car, and the radio, batteries, and motors for differential thrust first from a boat I picked up at Wal-xxxx. I've found better doaner vehicles since my first at Big-Lots for $6.99 USD, a crazy 3 wheeled vehicle that has great range and a light PCB rx. I use either Reynold Wrap or a Grocery bag for the skirt just like these. Props are the problem, where do you find a 3/4" prop? You make them from balsa... I'll post pic's in tomorrow if they are requested.

Bart

[Sensiblenick]

http://www.rcgroups.com/forums/showpost.php?p=2920031&postcount=10

you might find this of interest.... It works on pure power... :D

[hcopter]

Sensiblenick,

I like it! I bet it is fast :)

[BartMan]

These are cool, I've always used a seperate lift fan that just has an on-off swith, then some thrust and steering system. I'm going to have to try one of these RAM Air hovers. You guys have done a great job making them FAST.

Bart

[flyingmonkey350]

I decided to make somthin simmilar to this but with 1 fan for lift and one for forward. Im having a few probs.

1. when i run it on the road gravel gets swept into skirt
2. is there a rule of thum on how big skirt should be
3. its to fun abd all i do if race down street
4.how do i get a job cleaning streets lol i bet y streets are alot cleaner now i bet i collected a few pounds or more in gravel all together

[experimental_pil]

Flying Monkey,
Most of the hovercrafters skirts are pink with flowers :-)
Jking.
My hovercraft as well as the others I have seen are closed. There is no way for anything to get in. You just need to have a hole somewhere for the air to get out.
Yes there are some skirt calculations to be made. I have no clue what they are yet, lol

Maybe we should have a hovercraft forum here...mods?

I'll try to find a link for the skirt calcs

[experimental_pil]

Ok Flying Monkey,
Go here and then go to the files page. There are some skirt calculators there.
http://www.rc-hovercrafts.com/

[BartMan]

That one can get pretty complicated, for an easy to build and understand hovercraft, you might try Kevin Jackson's build instructions, it should give you a few idea's. http://members.aol.com/modelhov2/index.html

[y.takahashi]

Hi!
It is a surprise however that the surfacing height is high though seen the type without the skirt seemingly. ｡An easy structure is very good for it.

[Sensiblenick]

Sensiblenick,

I like it! I bet it is fast :)

IT is.. it's insanely quick. I have to admit that it's only really controllable at slow speeds.
I'm still not sure what full speed is... I've only run it in a big sports hall, and it hasn't ever achieved full pace!! It's steerable so long as you're accellerating, but I'd have to say that the moment you back off, you have an unguided ice-cream tub with a self sustaining ram-induced air cusion.

It's rather pointless infact.... unless you want to have a very noisy thing that is capable of holwing across a sports-hal floor at warp-speed :)

The faster it goes, the bigger the air cusion. It appears to be sitting at around 20mm altitude when it's beginning to get fast..

[rweatherly]

hcopter-

Great design. Going to try it on water (after a little water-proofing of the electrics).

[hcopter]

Ok, since there has not been much interest in kits for these hovercraft I am dropping the kit prices as follows to try and sell the kits that have already been cut rather than having them sitting around. Hopefully they will give a few people some good cheap fun.

Small Kit 9x13" for 6 inch prop: $5 + $3 priority shipping = $8 total
5 kits left

Large kit 11x15" for 8 inch prop: $8 + $3 priority shipping = $11 total
4 kits left

Email me at ylf@cox.net if interested.
First come first served based on emails received

Thanks,
Mike

[jimjxsn]

I'm interested in the plans. Just sent you an email - so, let me know the details.
Jim

[hcopter]

3 small kits remaining.

[nshytyy]

www.scalespeed.com

[psycho_klown66]

Email sent for 1 small kit. PayPal ok?

[psycho_klown66]

Payment sent! :D

[MILLERTIME]

Mike, Got boat today.
Thank You
Don

[yilong]

sorry,
My English is very poor.

I see the picture in taiwan,
At first , didn't see hovercraft bottom.
So I build another design.(without skirt)
It can play,
and very funny.

see the short movie.
http://www.align.com.tw/alignweb/files/YILONG/fd940412.wmv

[jimjxsn]

Mike,
Got the kits and built one today. Boy, these work great! Thanks and let me know if you cut another batch of the large size kits in the future.
Jim

[Flying-Apple]

I come from Taiwan
Therefore my English is not certainly fluent

First shares my work

http://homepage.mac.com/antims/.Pictures/RC%20World/low_flying%20008_resize.jpg

http://homepage.mac.com/antims/.Pictures/RC%20World/low_flying%20010_resize.jpg

http://homepage.mac.com/antims/.Pictures/RC%20World/low_flying%20011_resize.jpg

http://homepage.mac.com/antims/.Pictures/RC%20World/low_flying%20012_resize.jpg

http://homepage.mac.com/antims/.Pictures/RC%20World/low_flying%20013_resize.jpg

[BartMan]

Looks good, How's it run? I really like the leading edge of the platform, what did you use to make it?

[hcopter]

Flying-Apple,

Looks good, I like the rounded shape and the "bumper" edging. Also the prop guard is a nice touch.

Mike

[Flying-Apple]

Looks good, How's it run? I really like the leading edge of the platform, what did you use to make it?
fine

i use a hair dryer to let it be fixed , but be careful not too closer.

[Flying-Apple]

Flying-Apple,

Looks good, I like the rounded shape and the "bumper" edging. Also the prop guard is a nice touch.

Mike
Hi Mike

thanks , but i thought mine is much more like a cushion of toilet
:p :p :p

[psycho_klown66]

I have 2 questions.

I have a extra piece of foam that I don't know where to put. I know I should post a picture (hopefully you'll know what I mean.)

Which prop do you suggest for the smaller kit?

Thanks!

[hcopter]

Can you describe the piece of foam? How large is it? There is a small recangular piece that is a servo doubler and there is a piece with two slots that is intended as an optional, movable spoiler on the front or rear fins.

The small kit is designed for a 6 inch prop, just choose one that will load your motor correctly, I often cut down larger props to get one with a wider blade for better performance at lower RPM's.

Mike

[psycho_klown66]

It's the one with the 2 slots. It's the spoiler. :D

Where did you put your spoiler and what effect did it have?

Thanks!
Mike

[hcopter]

I put it on the front fins creating down force to help hold the nose down at speed. However, I have found that the nose will still come up if you go too fast and if you angle the spoiler up, so it is lifting the nose, it will lift the nose at a slower speed and act as a brake so you don't flip over backwards as easy. The fun is in experimenting with it :)

Mike

[psycho_klown66]

I don't understand the skirt. I got a plastic bag, wrapped it around. I've noticed that on one of your pictures, that you have a huge hole in the center. Is it supposed to be taped down there, or just free?

Thanks!

(almost there... :) )

[hcopter]

It should be free in the middle.

1. Set the hovercraft on your piece of plastic and draw/trace a line around it.
2. Draw another line 1 inch outside of the first line.
3. Cut the plastic on the outside line. (This will provide the extra plastic that can fill with air and create the "pillow" of air. The looser the skirt is under the HC, the higher it will ride)
4. Mark 3 inches in from the inside line (both sides and both ends) and draw a rectangle with rounded corners.
5. Cut out the rounded rectangle.
6. Tape the outside edge of the plastic on around the outside edge of the HC bottom, the plastic should be taped right at the top edge of the foam. Leave the center opening free.

Let me know if this isn't clear and I'll take some pictures.

Mike

[aeronavale]

hcpter

I would appreciate the pictures. The skirt is my problem. I have seen real skirts with the segments and the fingers but this is not a practical application for modeling. If you could provide drawings, plans dimensions, any information would be appreciated.

[hcopter]

These two pictures show it pretty well. You can see the tape around the top edge with the plastic skirt just coming up over the edge and held in place by the tape. On the bottom you can see the line I drew outlining the bottom of the hovercraft and the rectangular opening spaced in 3 inches. It's simple and easy and works well.

Mike

[joao]

Here is my first attempt of building an hovercraft. Not yet water rated

The model was created with the eyeball method ;)

Moves quite fast in a straight line. Has a large turning radius.

A skirt will be instaled soon.


Regards, João

[joao]

Second prototype, this time with a single motor. Fast, very small turning radius.

Regards, João