Introduction: The Big Bang (pocket-sized Rocket Launcher)

About: I'm a high school student who loves making and hacking stuff!
This little gadget can send a small Coke bottle up to 300' with ease. But be careful, this little devil can cause some serious damage to people and property if not used responsibly. Adult supervision is recommended.

USE AT YOUR OWN RISK!

Step 1: Gather Your Supplies.

1. Coke bottle cap.

2. Tubeless tire valve.

3. Knife or drill bit.

Step 2: Warning!

Don't use a water bottle cap. I've tried this style of cap before, and at 200 psi they usually blow up!

Step 3: Drill or Cut a Hole for the Tire Valve.

Try to center the hole better than I did. I'll have to get another cap. :(

Step 4: Shove the Tire Valve Though the Cap.

Step 5: Strip Off the First Course of Threads on the Cap.

This takes a lot of practice. Be extremely careful!

The gray cap is before the thread removal and the blue one is after.

Step 6: Testing.

The goal is to strip enough threads so the bottle cap can be removed in one turn. Only remove a little bit of plastic at a time. Then test. If you remove too much plastic the airtight seal will be compromised.

Step 7: Launching.

Use the pics above as a guide for how to properly rotate the bottle. Practice without air pressure until you have completely mastered the motion. When you feel comfortable with the twisting motion, try only a little bit of air pressure: about 20 psi. Make sure to let go of the bottle as soon as it is fully open. Getting the feel for this is tricky, so don't get discouraged. Once you are comfortable with that slowly increase the psi in small increments. Don't go over 150 psi. Past that point you risk an explosion!