Kataraman (with impeller) - spiral vase printable

It turned out that it don't runs straight ahead if driving this boat http://www.thingiverse.com/thing:204303 with an impeller. It runs more like a drunken sailor ;-)
Therefore I designed a kataraman that has much more directional stability.
This time I got something bigger for testing - a bath tub ;-)
http://www.youtube.com/watch?v=kuZudg1GadM

I used the same drive again that Oliver designed for his impeller-truck :-) http://www.youtube.com/watch?v=h_ZOYQsWkps