Build a Hovercraft: Advice for Beginners

[bassplayer142]

Me and my friend have been putting some serious thought into making a hovercraft. Just something basic that could maybe hold the weight of a person or a few. I have a old push lawn mower that I may be able to scrap the engine from. I don't know much about engines and the way they are built but I would really love it if this engine would work for the job. Does anyone have experience with this type of thing that could give me advice on this. I understand I would have to design some type of fan that would be attached to the motor.

Thank you for any advice or assistance.

 

[russ_watters]

There are plenty of kits and plans available on the net, you should be able to find what you need via google. A lawn mower engine with an appropriate fan should be enough to lift a person. Here's a calculator: http://www.olshove.com/HoverHome/hovcalc.html

I plugged in some off-the-cuff numbers and found that a 6'x4' skirt 0.5" off the ground, holding a total weight of 250 lb (including the hovercraft) requires a 1.5 hp motor, though one big caveat is that it doesn't say if that includes an efficiency factor for the fan (it would only be about 50%).

 

[mtworkowski@o]

This will be the coolest. Here's what I know. Light weight is bigtime important. Flat platform with skirt made of, oh shall we say, swimming pool liner. Corners to be made some crazy way that you'll find out about on the web. Oh, I lost my train of thought. Alright, listen, a ducted fan is better than just a fan or prop but it's more difficult to make. You decide after you get into it. I'm going to say 2/3 air for lift and 1/3 for forward motion. build your prototype with an ax and your finished craft more carefully.
It can be done and you can do it.

 

[bassplayer142]

Thanks a lot for the responses so soon. I am so excited for this that I stayed on to see if anyone replied quick. I will be sure to post pictures when I'm done and if it works. Thanks!

 

[bassplayer142]

I have attached a picture that would resemble the skirt part or just an idea. The black would be the frame, the red would be the skirt, and the blue is the flow of air. Does this look reasonable to anyone. It would be a wall skirt.

 

[Danger]

That looks very reasonable. Good luck with your project, and keep us updated.

 

[bassplayer142]

It has been quite a while and I guess we never have time, but we finally got a 18hp engine running from an old tractor. Our next obstacle is looking for an appropriate fan. I have been thinking about car radiator fans but I don't know if it can be safely mounted and allow enough ft^3/min. Anyone have any experience with this? thanks

 

[Mech_Engineer]

It has been quite a while and I guess we never have time, but we finally got a 18hp engine running from an old tractor.

How big is this engine? A tractor engine sounds heavy and slow-revving to me...

Our next obstacle is looking for an appropriate fan. I have been thinking about car radiator fans but I don't know if it can be safely mounted and allow enough ft^3/min. Anyone have any experience with this? thanks

A radiator fan might be large enough depending on the weight you need to lift and how high it needs to go. I've seen estimates that mechanical puller fans pull around 10,000 cfm or more at multiple thousands of rpms (say 4000 rpm).