I designed and printed a balloon powered boat for my son's birthday last month. Blow up a balloon and stretch the the balloon opening over the hole at the top. I did find that once the balloon is attached, it's easier to inflate by blowing into the bottom of the boat rather than taking the balloon off each time.
There are 2 prints, the boat and a name plate. I'm not sure how to make the name plate customizable in thingiverse so I included a blank that you can download to edit the .stl, or, probably easier, just make one in the software of your choice - it's a 70 x 22 x 5 mm slab with a name cutout. The boat works just fine without the nameplate.
Printer Brand:
Creality
Printer:
Ender 3
Rafts:
Doesn't Matter
Supports:
No
Resolution:
.28 (nothing special about this as long as the air channel prints okay)
Infill:
10% Grid
Filament:
whatever cheap stuff I had PLA
Notes:
I was pretty new to 3D printing and designing (I still am) when I created this so take those settings with a grain of salt. It's a simple print so just have fun.
The author marked this model as their own original creation. Imported from Thingiverse.