Easy 3D printable design

https://www.printables.com/model/496157-jetboat-hull-new-design

I wanted to do a powerfull boat. My 3D Printer has 200mm Z height so i designed one boat with 400mm - two parts - for shallow water. Both designs can be screwed together so if you want to change something you only have to print one piece new.

There is a hull extension available if you want 100mm or more additional length.

https://youtu.be/lupZR7mE_n8

https://youtu.be/9t4BScsD3CU

Video2

Step 1: Boat Design

I made a boat fitting my 3D printer (Anycubic i3 Mega) and then i checked which is the biggest jet drive i can put in. It resulted in a 40mm jet which is really big for a boat of this size. But my opinion is you can only have to less power never to much!

By the different propeller designs - two, three or 4 blade you can adjust the thrust.

I wanted to do two hull designs. One for speedruns on flat lakes and one for wild river runs.

All native 3D date is supplied under https://www.prusaprinters.org/de/prints/51680-3d-p...

There is always a hull only part and a cut part to make the customized hole for the parts.

I used a 0.8mm nozzle on my printer for the big parts. All walls are made of a thickness multiplied by 0.8mm so it is easy to print and no issues with gaps or weak walls.

One piece takes around 10h to print with a layer height of 0.3mm.

The cover can be a 1mm thick plastic / plexi sheet just cut it for best fit.

DESIGNS FOR THE DECK ARE VERY WELCOME!

Step 2: Print Instruction

nozzle 0.8mm

perimeters 2

infill 15-30% i used gyroid

Top and bottom thickness 1.2

no supports

bridge setting enabled

Total material used 560g for the short boat

i suggest to print one by one not both or all 3 parts together just in case something fails

Step 3: Jet System

Jet diameter - prop diameter is 40mm

at the motor side there is a sealed ball bearing which carries the thrust lod. In front of it there is a clamped sleeve to bring the force from the shaft to the bearing.

In the diffusor there is a brass bearing to keep the prop in the middle.

Drive Dog Shaft Clutch is clamped to the shaft and drives the prop.

Step 4: Bill of Material

if you have nothing it will be around 100€ :

605-2RS 5x14x5mm ball bearing (2RS means with rubber seals)

M3 Link Rod End Ball Joint Metal 100mm center to center

Model Boat Metal Drive Dog Shaft d5

rubber Bellows Radio Box Seals

FT5320M 180 degree Servo waterproof

Copper Base Bushing ID 5 OD9 L9

Three Jaw D25L30 Coupler Aluminium Flexible

DumboRC X6A Transmitter with receiver

303 Stainless Steel Rod OD 5mm L 200+

Water Cooling System Jacket 36-L

ID 5mm Oil Seal Gasket TC Type 5x15x6 mm

5mm metal Bushing axle sleeve Outer diameter 10mm Stainless steel shaft sleeve

Waterproof 3670 2150KV Brushless Motor 120A Brushless ESC Combo Set

Brass Straight Hose Pipe Fitting Equal Barb

4mm Transparent Silicone Rubber Hose 4mm

4S or 6S or 2x3S Lipo

M3 screws

M3 brass inserts

Step 5: Assembly

To seal the hull i painted it with Epoxy. Before painting i use a long blade of a cutter to flatten the surface.

The faces between the prints i sealed by using double sided tape so that its possible to take it apart if necesarry.

To screw it together you just need some M3 screws and M3 inserts which you melt in - i use a soldering iron for this purpose.

Step 6: Electronics

I wanted to keep it simple an cheap but fast.

So i decided to use a 3670 motor which means diameter 36mm 70mm length - brushless.

The chosen motor has KV of 2650 which means per supplied Volt you get 2650 turns/min so if you go max and use a 6S (6cell) Li-Po battery you have 22.2V results in 58000rev/min - of course without load. For the beginning i will use only 3S - 29000rev/min.

All components are waterproof.

For the receiver i have chosen on with gyro - this should help too keep the boat in a straight line on speed runs.