Page 1 of 2 12 LastLast
Results 1 to 8 of 12

Thread: Advice and suggestions sought

  1. #1
    More than 10 posts!
    Join Date
    Aug 2009
    Posts
    21

    Post Advice and suggestions sought

    Friends, i'm at a very crucial juncture of my project - the Hovercraft. I've my first review in 10

    days time. I'm in the process of material selection now. Despite going through numerous

    articles and essays on Hovercraft, doubts still persists. Your advice and valuable suggestions are sought for the following questions:

    1. I've decided to use a 12mm ply coupled with a 5mm foam for my hull. Is it ok or shall i go with ply (of 19mm) alone?

    2. Skirt design baffles me completely. I'm yet to find a suitable website / article / thread in a forum that would help me with it. Though i've selected a material of nylon for it and decided to go for bag skirt, am unable to understand as to what dimensions the skirt should be cut and what calculations it involves. Please help me with this.

    3. Which type of blower is suitable? An axial one or a centrifugal one? I've seen some centrifugal blowers and am inclined to go for it. Should i proceed or should i reconsider?

    Your valuable advice and suggestions are sought. Please help. I took upon this project only after i found out that i can bank on the people in this forum who would help me with any doubts that may creep into my mind in the course of this project.

  2. #2
    Extremely active > 250 posts! Club Member
    Join Date
    Mar 2009
    Posts
    337

    Default Re: Advice and suggestions sought

    1 - 12mm or 19mm ply is very heavy for a hovercraft - small craft use as little as 4-5mm ply - foam is only useful if it is sandwiched between plywood layers

    2 - can't help you with bag skirts - i can if you coose segmented

    3 - Axial fans dominate for thrust and lift for small hovercraft - larger craft use centrifugal - manufacturers such as multi-wing and hascon wing are our main source of fans

    hope that helps

    tony

  3. #3
    Extremely active > 250 posts!
    Join Date
    Mar 2009
    Posts
    259

    Default Re: Advice and suggestions sought

    Ashwin,
    As previousl advised why don't you go to the HCGB Homepage and look at the "Downloads " that are available.

    You do not appear to have decided on anything at all and yet you are asking for help.
    Without some input from you as to where you think you are going it would take a weeks of questions and answers.
    Most of the info you require is available on this website.

    You can even get plans.

    Kip

  4. #4
    Forum God > 400 posts
    Join Date
    Mar 2009
    Posts
    420

    Default Re: Advice and suggestions sought

    1. Impossible to answer without some idea of the hull structure and shape. As Tony says, 12mm ply is too heavy for any design. Using 5mm foam is pointless - it's too thin to provide any composite strength (if you are using it that way) and too small a volume to give much useful flotation.

    2. There are plenty of sources on skirt design on the web - check http://www.4wings.com for example.

    3. Once more its impossible to provide an answer without more detail (craft weight, payload, cushion area, operational limits, etc).

    I don't want to put you off but hovercraft look simple in theory but it's notoriously difficult to design one that works properly (the difference between a working and non-working craft can be something very small - there is no such thing as an almost-working hovercraft )

    There are designs out there for simple hover craft - from the vacuum blower "disc" (http://amasci.com/amateur/hovercft.html) to the UH entry level craft (http://www.hovercraft.com/content/in...ain_page=index) and others.

  5. #5
    More than 10 posts! Club Member
    Join Date
    Jan 2010
    Posts
    18

    Default Re: Advice and suggestions sought

    Ashwin,
    Reducing the overall weight of a hovercraft should be a primary design consideration.
    The strength of a craft is not acheived by using strong heavy materials but by using construction techniques that allow the use of lightweight materials. Techniques such as folds and curves are examples of this.
    An old but very succesful design can be seen here:-
    Caliban
    Last edited by Ken_A; 12-Jan-10 at 07:11 PM.
    Ken Anderson

  6. #6
    Extremely active > 250 posts!
    Join Date
    Mar 2009
    Posts
    283

    Default Re: Advice and suggestions sought

    i have a sneaking suspicion, this hovercraft he wants to build is a plywood disk with a leaf blower??
    Jon

  7. #7
    More than 10 posts!
    Join Date
    Aug 2009
    Posts
    21

    Default Re: Advice and suggestions sought

    Friends, Thanks a lot for responding promptly.

    Mine is a single seater craft of dimensions 4ft X 7ft (may extend a little say 4ft X 8ft).

    I planned it for a payload of 150kg but am ready to relax this limit a bit say 200 kg including the driver.

    Am planning to use 2 stroke petrol engines for the lift as well as thrust.

    @ Tony: Will a 4-5mm ply be good enough to withstand the weight of the engines?

    @ Kip: You're right. I've a lot to refer before i post my next thread. Thanks

    @John: Thanks a lot. Your links were really helpful. I want my hovercraft to be something like the UH - 6F Trainer.

    @ Ken: Thanks a lot

    @ Curtis: Its not a leaf blower craft. Though my first impression of hovercrafts was formed after watching videos of leaf blower crafts, i intend to build something better. My craft will be better than a simple disc type leaf blower craft but it will not be as complex as the crafts that i come across in this website (those racing crafts).

    The craft that i intend to build will be somewhat like these:

    http://www.vtualerts.com/wp-content/...hovercraft.jpg

    http://cheaphovercrafts.tripod.com/i...target=tlx_new

    http://www.hovercraft.com/content/in...ain_page=index

    I intend to build it more like the first link provided than the other two.

    I suggest that those wishing to help me by providing advice may take a look at the above links so that they get an idea about my craft and its requirements.

    Thanks a lot everyone, once again.

  8. #8
    Forum God > 400 posts
    Join Date
    Mar 2009
    Posts
    420

    Default Re: Advice and suggestions sought

    Ashwin,

    To be honest, looking at your budget and plans, you would be far better off just making the disc type craft and fitting a simple leaf blower for lift and some thrust. It will easily carry 150Kg on a smooth surface (I've built one and it does!) and will probably perform as well as any of the craft you have listed (apart from going onto water like the UH6F).

    Your choice should be the disc-type craft or a "proper" hovercraft that will have some functionality - none of the craft you show are practical in any way. To build a functional hovercraft your best (and lowest cost) option is to buy plans for a proven design. Spending more money (than the disc-type) building something in-between that has no purpose seems pointless to me.
    Last edited by John Robertson; 13-Jan-10 at 07:26 PM.

Similar Threads

  1. fan advice
    By jon_curtis - n/a in forum General Forum
    Replies: 0
    Last Post: 19-Jan-09, 06:01 PM
  2. fan advice please.
    By jon_curtis - n/a in forum General Forum
    Replies: 5
    Last Post: 15-Dec-08, 04:27 PM
  3. Hello & some advice please
    By Colin - n/a in forum General Forum
    Replies: 13
    Last Post: 30-Jan-06, 09:04 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •