Bottle Rocket Launching System B.R.L.S.

Bottle Rocket Launching System B.R.L.S
3D-printed Bottle rocket / Water rocket design with minimal non-printed parts.

The launching system consists of a launching base, a valve-to-bottle adapter and launching pin. Attach a string to the launching pin to release the rocket from a safe distance.

The design goal of this project was to minimize the non-printed parts needed. Non-printed parts necessary is a Schraeder valve from a innertube, preferably an old leaky tube, and a o-ring. A PET bottle is also needed of-course. The design uses 3d-printed M8 bolts and nuts which may be replaced with real hardware if available. 

The base should be fixed securely to the ground in some manner, I used tent-posts from an old tent, but you may as well screw it down to a piece of MDF or something similar. You don't want the base to be moving around while trying to release the pin.

I found that about a third of the bottle filled with water gives the best result, but you need to play around and test what works best for you.

Since the part is going the hold some pressure, good layer adhesion is needed. PETG or ABS is recommended.

Caution: Be careful and use at own risk! Never pressurize your bottle above its safe pressure and use appropriate safety gear. At a minimum safety-googles and some distance. Make sure the base if fixed securely to the ground before use. 

I included a nose cone and wings that fits the bottle I used, A 1.5l PET bottle. As all bottles are different these may not fit on yours.

Bill of materials:
1 or 2 x O-ring, 2.4 x 18 (OD) mm
1 x Schrader valve from a repurposed inner tube
1 x PET Bottle
1 x String
1 x Bicycle pump with pressure guage

Optional (3d-printed parts available):
3x M8 Nut
3x M8 x 30 mm

Print recomendations
- PETG, ABS or similar
- 0.2 mm layer height
- 40% Infill