Homebrew PCBs

I'm very suprised the fan dosn't work, i suspect
it has t do with the different density of water/air.
perhaps the water was only thrown outwards, not up.

I believe a 2cm tube is very, very small. you need a lot
of rpm to make such a small tube work. I'd try 5cm with that RPM.

You could try to make it a bit more like a centrifugal pump,
make a "fan" with vertical fins throwing the water out, and then make a
deflector which takes that water and reflects it upwards.
It seems the high density of water lends itself better to use the 
centrifugal
force than a normal fan.
But then, every ship has a screw, and i'm really suspicious about your 
results.
maybe the water didn't properly reach the fan, you should flood it.
also try removing blades to leave only 3 or so.
You could also use a bent strip of metal for two blades.
(the pc fan probably has a big blocket center area)


ST


On Wed, 21 Jul 2004 13:35:01 -0000, cruizzer77 <atlantis7@...> wrote:

> Thanks for your replies!
>
> I tried the one with the propeller, mounted a small cpu fan
> propeller on the bottom of the tube and the upper part of a half-
> liter fanta bottle over it to form a kind of funnel. The rotating
> direction was correct but there happened _nothing_ when I sped it up
> to 5000 turns (I used water to test it). By the way I simply used a
> drill with a flexible to drive it. The problem is that I'm using a
> KRH M20 electrician's installation tube with an outside diameter of
> 20mm which is too small to fit any propeller inside. But the idea
> with the 3 holes sounds interesting, I imagine that the holes are
> drilled with an angle. What diameter does the tube approximately
> have?
>
> Regards
> Martin