this model designed for engines that work in the water, and designed with 4 and 3 float board for different situation.
the basic scale is about 3cm high and 3cm width
and a hole under it 1.5mm diameter
it can be re scale up to 120%
designer, work in my own work shop.
that would be my pleasure that print my designs, if you do that please send me some pictures, and tell me what to do for making better design.