I want a hoverboard/ultralight helicopter.

[speedevil]

I was browsing my favourite chinese junk site, and came across
http://www.dealextreme.com/details.dx/sku.15230

This is a 70mm diameter fan that takes 580W of power, and produces
1.1Kg of thrust, and weighs 116g.

Imagine a board around a meter round, with a large number - around 150
- of these fans around the edges, with a nutter perched on top, riding
it like a segway, with a collective control to go up and down.



Some details.

The fans are canted slightly to overcome any rotational effect. (of
course in a production craft, you'd want to source fans of opposite
rotation - but...)

Parts list:
http://www.dealextreme.com/details.dx/sku.15230 - thruster $38 - 116g
http://www.dealextreme.com/details.dx/sku.11983 speed controller - $29
- 59g
http://www.batteryjunction.com/tenergy-31132.html - $80 230g, 30Wh
18mm plywood - 1m*1m - 18Kg
Nutter - $0 - 100Kg.

Assuming that we run the fans normally at 500W, and they really
produce 1Kg, and the rest of the margins come from getting better
stuff as we're buying in volume, and not picking the first that
occurs.

Each battery can run one fan, and needs one ESC, for a total cost of
$150, a weight of 380g, and a thrust of 1Kg - leaving 600g of thrust.

For a 118Kg payload (plywood + nutter), that means 200 units to hover,
under normal conditions, not counting burst power, which will be a bit
higher.
Call it 250 units, giving a

So, we have a $30000 (assuming quantity discounts) 60Kg heliboard,
capable of free flight for 2-3 minutes.

Anyone see any major flaws?

This is of course merely a proof of concept doodle - in practice you'd
probably want to optimise fan diameter, RPM, and source the parts
sanely, I wouldn't be surprised if this might result in a third the
price or less if you were building a dozen.

Of course, in practice, you'd need details like:

Canting the fans to avoid overall torque (or source counterrotating
fans).
Redundant controllers - each doing a small group - (4?) of fans.
(this is where the large number of fans is a big plus)
Safety features - an altitude limiter to 10cm, and a promise never,
ever to press the big red button.

Does anyone see any real obstacles to this - what would the legalities
be if I was to try to sell this? I assume there'd be no chance in
hell?
(I do not have any funds to invest in this)

[wright1902glider]

On Oct 21, 3:55*am, speedevil > wrote:
> I was browsing my favourite chinese junk site, and came acrosshttp://www.dealextreme.com/details.dx/sku.15230

Does anyone see any real obstacles to this?


If you're thinking that its going to "fly", I have two words "Moller
skycar". He used 8 Mazda engines. No soap. Not convinced? How 'bout
"Avro Skycar," or whatever they called it. It used two jet engines.
Couldn't clear an 8-foot fence.

Now if all you want to do is stand on top of a surfboard-style
hovercraft, I'd suggest the following:

1 gas-powered leaf blower (31cc is plenty of power)
1 3ft dia. section of 3/4" plywood.
1 section of 6mil polyethylene sheet big enough to cover one side of
the plywood and wrap partially around the other
1 staple gun loaded with 3/8" staples
1 roll of duct tape

To build:
cut out the plywood deck
cut a hole in the deck just big enough to fit the nozzle of the leaf
blower into
cover one side of the deck in plastic, wrap the edges around the other
side, staple in place
cut 6 2"-holes in the plastic, spaced 60 degrees apart, approx.1/2 the
radius of the deck from the edge of the deck
turn the deck over, duct tape the plastic edges to the deck and maybe
staple the tape down too
insert the blower nozzle into the hole
don't spend more than 1 hour building this. If you do, you've done it
wrong.

To fly:
start the blower and set to full power
jump on
try not to kill 'urself

Congratulations!
You've just used cheap junk to achieve the same result your $30,000
250-motor hoverboard would have. Now take the $29,940 that you saved
and go buy a nice used Ercoupe or something.

This will also work using an electric blower and a long extention
cord. Wanna guess how I know???

Harry Frey
mayhem ensues

[M Kennedy]

Is it possible to maneauver this hovercraft simply, for example by leaning
in the direction you want to go, or is a separate thrust mechanism always
required?
Thanks,
MK

"wright1902glider" > wrote in message
...
On Oct 21, 3:55 am, speedevil > wrote:
> I was browsing my favourite chinese junk site, and came
acrosshttp://www.dealextreme.com/details.dx/sku.15230

Does anyone see any real obstacles to this?


If you're thinking that its going to "fly", I have two words "Moller
skycar". He used 8 Mazda engines. No soap. Not convinced? How 'bout
"Avro Skycar," or whatever they called it. It used two jet engines.
Couldn't clear an 8-foot fence.

Now if all you want to do is stand on top of a surfboard-style
hovercraft, I'd suggest the following:

1 gas-powered leaf blower (31cc is plenty of power)
1 3ft dia. section of 3/4" plywood.
1 section of 6mil polyethylene sheet big enough to cover one side of
the plywood and wrap partially around the other
1 staple gun loaded with 3/8" staples
1 roll of duct tape

To build:
cut out the plywood deck
cut a hole in the deck just big enough to fit the nozzle of the leaf
blower into
cover one side of the deck in plastic, wrap the edges around the other
side, staple in place
cut 6 2"-holes in the plastic, spaced 60 degrees apart, approx.1/2 the
radius of the deck from the edge of the deck
turn the deck over, duct tape the plastic edges to the deck and maybe
staple the tape down too
insert the blower nozzle into the hole
don't spend more than 1 hour building this. If you do, you've done it
wrong.

To fly:
start the blower and set to full power
jump on
try not to kill 'urself

Congratulations!
You've just used cheap junk to achieve the same result your $30,000
250-motor hoverboard would have. Now take the $29,940 that you saved
and go buy a nice used Ercoupe or something.

This will also work using an electric blower and a long extention
cord. Wanna guess how I know???

Harry Frey
mayhem ensues

[speedevil]

On Nov 6, 6:26*pm, wright1902glider > wrote:
> On Oct 21, 3:55*am, speedevil > wrote:
>
> > I was browsing my favourite chinese junk site, and came acrosshttp://www.dealextreme.com/details.dx/sku.15230
>
> *Does anyone see any real obstacles to this?
>
> If you're thinking that its going to "fly", I have two words "Moller
> skycar". He used 8 Mazda engines. No soap. Not convinced? How 'bout
> "Avro Skycar," or whatever they called it. It used two jet engines.
> Couldn't clear an 8-foot fence.
>
> Now if all you want to do is stand on top of a surfboard-style
> hovercraft, I'd suggest the following:
>
> 1 gas-powered leaf blower (31cc is plenty of power)


Yes, a leaf-blower type teeny hovercraft is of course much more sane,
and unlikely to kill you.

Also lots less fun.

However - the moller skycar and this devlice have key differences that
make this somewhat more plausible.

It's got a flight time of 3 minutes.
Everything is off the shelf.

[speedevil]

On Nov 8, 5:51*pm, "M Kennedy" > wrote:
> Is it possible to maneauver this hovercraft simply, for example by leaning
> in the direction you want to go, or is a separate thrust mechanism always
> required?

The initial idea was simply weight shift to manoever - however in the
same way that a segway does not directly control the motors from the
weight shift, the weight shift would be a control input, not a direct
control.

So, you lean forwards, the CG shifts forwards, and the platform tilts
forwards, until it comes to its limit of 5 degrees (or whatever), at
which time it won't tilt further (and tilts back if airspeed limits
are close).

There is a little control yoke, like on a segway, but the rider is
strapped in to a seat like a bicycle seat, and even if they become
unconsious their weight shift will not cause the platform to become
unstable.

Plenty of reserve power is the key here.