Hi guys:

I made it easy using two plastic syringes, a 60cc and a 10cc. Let the images (and video) speak for themselves:

[link=https://picasaweb.google.com/105403795492677221295/BowThruster?authkey=Gv1sRgCNiiyPLFzb_rQw]Homemade Bow Thruster[/link]

Note: the test was made using a low rpm motor; but a test I made using a powerful 540, left me thinking about building a drive system without propeller...

Regards,
Robert