Valken/Hakkotsu Thunder B CO2 grenade shell 2 seconds

This is an optimized, 3D-printable shell for the popular CO2 sound grenade cores (Thunder B, Valken, Hakkotsu). This project is a remix of the model from Thingiverse (ID: 6326494), specifically redesigned for better reliability, easier field use, and consistent performance.

Key Improvements:

• Refined Ergonomics: The outer walls have been smoothed out to remove the "boxy" look, making the shell more aesthetic and easier to fit into standard grenade pouches.
• Smart Failure Point: A common issue with printed shells is that they snap at the thread, leaving the core stuck. This remix is designed to fail at the neck or pop the bottom cap. This keeps the thread intact for effortless removal and replacement—usually leaving only one large fragment behind.
• Timed Detonation (3MF): The included .3mf file contains specific modifiers that regulate the wall thickness/strength. In my tests, this results in a detonation time of approximately 2 seconds.

Printing & Material Specs:

• Tested Material: Extensively tested with eSun PLA+. This material provides the right balance of rigidity and impact resistance for a loud pop without dangerous fragmentation.
• Performance: The sound level is very loud and, in my opinion, fully comparable to the original factory-made shells.
• Settings: I highly recommend using the provided .3mf file. It contains custom modifiers in critical areas to ensure the shell bursts correctly and safely.

⚠️ SAFETY WARNING:

1. DO NOT USE PETG: PETG is too brittle for this application. Under high pressure, it tends to shatter into many small, sharp, and dangerous shards. This is a sound grenade for Airsoft use—it is meant to make noise, not cause injury.
2. Stick to PLA+ / Tough PLA: Only use high-quality PLA+ or "Tough" variants. These materials tend to tear or split rather than shatter.
3. Environment: Remember that grenade behavior can change depending on the ambient temperature and the specific brand of filament used. Always test in a safe environment.
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The success of this grenade depends entirely on the shell being 100% airtight. If there are even microscopic leaks in the walls or seams, the CO2 will hiss out slowly instead of building up the pressure needed for a loud burst. Also it's best to print it one by one. Do not fill your buildplate with those shells.

For Bambu Lab A1 mini Users: I found that features like "Clog Detection" and "Tangle Detection" can sometimes cause tiny surface imperfections or micro-gaps during the print. To ensure a perfectly solid and airtight wall, I highly recommend disabling these detections for this specific print. This ensures a continuous, smooth extrusion, which is vital for the grenade to function properly.
 

Credits: Remix of: https://www.thingiverse.com/thing:6326494