Spring propelled Catamaran

This is an evolution of my previous project, the Paddle Boat: (http://www.thingiverse.com/thing:918906).
The most difficult work has been mainly to transform the original spring motor (from gzumwalt, http://www.thingiverse.com/thing:452248) to have a longitudinal axis, a result obtained with a pair of bevel gears.

The motor has been reworked, with a stronger spring to have more power, necessary in this case to compensate the increased frictions.

It floats very well and with its large propeller is quite fast, although obviously the range is limited. Have fun!

Edit 04/10/2015. The hulls have been sligthly modified, moving all the engine group about 6mm to stern, this to reduce the (little) tendency to take on water from the bow.
Added a short video: https://youtu.be/0jJEtEEDj8I