This JetBoat is a remix inspired by the great work of wersy: http://www.thingiverse.com/thing:930577 and georgdoll jetpump version: https://www.thingiverse.com/thing:2249781 I scale it down to fit an ultimaker 2 or 3, to reduce numbers of parts needed. I redraw rooftop, and optimise the design to reduce as much as possible the use of support. It is drawn for a speed300 motor, with lipo 2S battery, and mini servo. This is an experimental version, that will be tested soon. If you do one, please send me what you think of it, so I can correct mistakes, or make it better. I have add the complete assembly in STEP, for those who want to modify it. First tests results: From the first mounting, it appears that the coupling (alloy + 2 headless screws) is crap. It's better to use a soft tube instead of the alloy part. Roof top is not optimized, too much support, bad aspect. A V2 version is available (much less support, better looking). New version of jetprop is available, still needed to be tested, but printable without suport, in one piece. The back of the boat is a bit heavy. When the boat is full speed, everything is OK, but when you stop and go again, the back goes down, and the prop has lots of difficulties to take its speed. I have drawn a back part to lighten the rear of the boat. It will be available soon. The boat is 50mm longer now, with a three parts body (nose, body, back). Anyway, keep in mind that with a three propeller jetprop, it is better if the prop is half in the water. If it is full under the water, the motor torque is not enoought to reach the speed. If you want to keep the "race" prop, wait for the back parts. If you prefer to keep the boat as small as it is now, change the prop the a smaller one, that will need less torque. Now, gentlemen, let's start your printers!!