1. Which National Aviation Academy?

2. What do you mean by, "I have built an RC hovercraft from scratch". From a kit, or from scratch. There's a big difference. Any photos?

3. Do you have any tools to work with.

You need to tell us a lot more before we proceed.

* I am atteneding NAA in Clearwater, Florida

* My RC hovercraft is my original design. It is a compression box fuse. with vents on the underside to inflate the skirt. The skirt its self is a plastic mesh tarp meteral with a square hole centered, each side of the hole has skirt straps to prevent a skirt blowout from one side or another. (Im still having osolation issues when I drive over uneven ground such as a speed bump or dip.) I have a few videos on youtube, I tried to post a picture but this site would not respond.

* Yes I have Access to tools through family and friends.

Heres the videos.

EAA, and get involved with a chapter. Those people will have lots of advice and tips on aerodynamics.

Go to Sun 'n Fun in Lakeland to scout around for ideas.

Dose anyone have any general knollege about what to consider or what's reqomended for hovercraft? Such as: 1. Skirt design- what skirt design is best suited for an all terain (water, road, grabble, sand, grass) hovercraft? What are the rules on the center skirt hole in a bag type skirt? 2. Engines- we need 2, a lift and a thrust engine. Where do I find props and ducted fans, and how are they mounted to a "prop shaft". With the thrust fan being a ducted internal design with a thrust vector nozzle for yaw control, what is recomened as far as mounting, and positioning of the engine. 3. More info- we don't want to brake and speed records, but it is gonna be a show hovercraft, so we don't want to struggle to hover, or maneuver. 4. Design- the design is based on the Lockheed F-35 Joint Strike Fighter, and will feature a streamline body with vertical doors over the lift fan, and a jet fighter inspired intake for the thrust fan. 5. Materials- what is common materials such as foam core for the fusealoge, sheet metal, skirt material? Thank you for your time

Q. 1, 2, 3, 4, 5

Q. 1a

Q. 3, 4, 5. http://www.google.com/search?q=Aero+hobby+supplies

It's easy, why not learn to do it?

I found the amazon link to not be very helpful, many reviews say that this is more of a childrens picture book of a specific hovercraft, and dose not thoughly explain the needed info.

the Google link was even less helpfull, leading me to just about every hobby except for hovercraft related sites.

the first link was pretty good, but the was most of the text is given with little to now pictures or diagrams, its hard to comprehend all of the different skirt designs, and what they look like, and function.

I didn't check the Amazon or google, but the 4Wings link is very informative.

GA for the great find and share.

Thanks Doorman

Beeler, I think it might be beneficial if you explain your level of accomplishments.

To help you out I need to know how much you know.

One observation I can make is 'dose' is a measured amount of material, like medicine - or slang for an acquired STD.

"Does" is as in 'did'. Not that it is a big issue as it's a common transposition, along with 'from' and 'form', a surprising number of highly qualified engineers make, but it does go to 'literacy', so comprehension, of those that are habitual.

Now, on the topic; do you understand the lift and velocity distribution functions of the plenum chamber?

MOst of what u typed was a riddle...

I know that a hovercraft flotes of a high pressure of air trapped by a skirt.

A skirt can impliment a bag or finger type skirt, or a combination of the two.

Ive modified and tested a few rc hovercraft designs, other than that im new, im not sure how big of a motor I really need, I was thinking a 10hp brigs spinning a 26" 6 blade lift fan, and a 10hp brigs spining a 26" 4-5 blade thrust fan.

Im still not sure about necisarry HP for lift, i used the calculator, but my hovercraft is an odd shape and theres no was im using a 100" fan on a 20hp motor like the calculator says...

OK, have you been here

In this diagram;

Do you understand;

A. the reason for the plate underneath?

B. that the space above is the plenum chamber

C. that gap around the plate sets the velocity pressure needed to trap pressure underneath

D. therefore, that it's the plate that transfers most of the lift to the body

At the end of that link there is some basic math that might be useful.

"... theres no was im using a 100" fan on a 20hp motor like the calculator says...

So what ARE you going to use? Adjust the size and weight of the craft to accommodate your selections.

You told us "...I have no experience in full size hovercraft...". 20HP doesn't sound unreasonable to me. It takes a lot of power to keep a heavier-than-air craft going. Perhaps this exercise will help you grasp some of these large numbers.

The 20hpbest is reasonable and makes since, the 100" fan dose not… I've seen bigger heavier commercial hovercrqfts, and homaid ones with about what I wanta use which is a 26" 6-8blade fan

Beeler, I believe that English is not your native tongue. If this is true, this image may not make any sense to you. I am not making fun of you, but this seems applicable:

No i'm like 5th. Gen. American, im just a horrible speller and spell check on my phone messes some stuff up

How do you calculate the amout of space between the lift distrabution plate, and the hull?

The distance would be greater than the 'slot' width at the edge of the plate. _{(Note; most sketches show the 'slot' far too wide)}

This might give you a better idea of what a plenum is good for.

I have italicized the key words in this section in that link.

Practical hovercraft use a peripheral skirt system, where the air from the lift fans is routed to a narrow slot around the edge of the hull, and bounded by a flexible skirt. Distribution of this air from the fans to the periphery is through a large-volume plenum chamber, so as to provide even distribution of airflow without sensitivity to the length of the direct path.