My fully printable RC Jet Boat. 

The two hull parts must be glued together and can be precisely positioned thanks to the holes for using 3mm screws.
The hood is designed to fit into the hull using two hooks at the front, while at the rear there is a hole for using a 12mm long 3mm screw.
 

A strip of adhesive foam (typically used to hermetically seal windows) should be used along the edge to prevent water from entering the hull.
 

In my project, I used a 2440 brushless motor and corresponding ESC, both liquid-cooled, so the hull has a hole at the bottom front and one at the rear. This allows the water to circulate through the duct and cool the parts perfectly.

I used a kit similar to this one:
[https://it.aliexpress.com/item/1005009301601606.html](https://it.aliexpress.com/item/1005009301601606.html) 
Unfortunately, kits and sizes change frequently, and some kits are no longer available after a short time. So, I designed the motor mount to be interchangeable (glued to the hull). So, if you find a different kit or the sizes are different, you can simply design the mount with the correct measurements for the motor you find.

You'll need a RC receiver, depending on the remote control you're using. I used this one:
[https://www.aliexpress.com/item/1005005880259941.html](https://www.aliexpress.com/item/1005005880259941.html) 

The digital servo motor for the rudder is similar to this:
[https://www.aliexpress.com/item/1005006887552361.html](https://www.aliexpress.com/item/1005006887552361.html) 

The 4mm drive shaft is similar to this:

[https://it.aliexpress.com/item/1005007951475624.html](https://it.aliexpress.com/item/1005007951475624.html) 
which has a metal outer tube with a PTFE inner tube: this prevents the hull from wearing out and prevents external water from entering the hull. Usually, a specific grease is also inserted inside the tube which helps keep the water out.

With the kit is also provided the Propeller, but you can use your favourite.

There is a support for the shaft that allow to insert an MR84 bearing (4x8x3mm), like this:

[https://it.aliexpress.com/item/1005008483136646.html](https://it.aliexpress.com/item/1005008483136646.html) 

To connect the crankshaft to the propeller shaft, you need a universal joint that looks like this:

[https://it.aliexpress.com/item/1005006861800732.html](https://it.aliexpress.com/item/1005006861800732.html)

that you must choose by carefully checking the measurements of the crankshaft and the transmission shaft that you will use.