Baking Soda and Vinegar Rocket!

For this rocket you will need these plastic test tubes.  Unfortunately you can't buy them in lesser numbers than 48, but the price is easy to accept. 

There are a number of different fin and nose cone options. This is largely because printing in TPU versus PLA for the fins and nose cones can introduce printing problems. 

You WILL have to print the plug in TPU as it needs to be able to flex a little to make the solid seal required to make the rocket POP!  We originally used the YOYI 3D Printer Filament,85A TPU Filament but this filament seems to be hard to get now, especially in California.   But we've had success using the Hatchbox TPU. 

There isn't really an advantage to the 3 over 4 fin rockets, it's more . aesthetics, the 4 fins make it looks more like the Estes Big Bertha.  

Depending on your printer and TPU,  there are a number of model options to try.