PP-R 20x2.8 PN16 Water Rocket Launcher Core

Pipe Size Explanation

This launcher core is designed for PP-R 20x2.8 PN16 pipe.

The pipe marking means:

- 20 mm is the outside diameter of the pipe

- 2.8 mm is the wall thickness of the pipe material

- So the inner hole of the pipe is approximately 14.4 mm (20 - 2 × 2.8 = 14.4).

Please note that real pipe dimensions can vary slightly depending on the manufacturer and tolerances, so test the fit before final assembly.

The launcher core uses a standard TR414 tubeless tire valve . Before installation, the mushroom-shaped rubber part of the TR414 valve needs to be cut off , so the valve can fit properly inside the printed core.

Required Parts

- PP-R water tube: 20x2.8 PN16

- TR414 tubeless tire valve

- O-ring for sealing: 3.5 × 22 mm

- Printed launcher core

Print Settings

- No supports needed

- Print with 3+ walls

- Use a structural, strong, or slower print profile

Assembly Notes

After cutting the PP-R pipe, make sure to deburr the edges .

Insert the O-ring into the groove on the core stage before installing the launcher core into the PP-R tube. The O-ring is used as the main seal. It needs to be slightly compressed between the PP-R tube and the printed launcher core part . This compression creates the seal and helps prevent air or water from leaking around the core.

For easier assembly, insert the beginning of the trimmed TR414 valve into the PP-R pipe first . You can use a small amount of water to help it slide into place. After the valve is positioned inside the pipe, push the printed launcher core into the PP-R tube.

The fit should be tight. The PP-R pipe is slightly flexible, so the core should press firmly into the pipe and compress the O-ring slightly.

Fit and Tolerance Adjustment

Depending on your printer calibration, filament type, material shrinkage, slicer settings, and wall accuracy, the fit may need small adjustment.

If the launcher core does not fit the PP-R tube properly, try scaling the part slightly before printing. In most cases, scaling between 98% and 102% should be enough.

The final fit should be snug. The O-ring should be pressed slightly between the tube and the core.

Safety Note

This part is intended for water rocket launcher experiments. Always pressure test carefully and stay clear of the pressurized launcher.

Do not exceed the safe pressure limits of your materials, pipe, fittings, valve, and printed parts. Printed parts can fail depending on material, print orientation, layer adhesion, temperature, wear, and print quality.

Use at your own risk.