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Step 10Operation
No doubt you can already guess how this is going to work!
Grab a water bottle and fill it about one-third to half full with water*. Stuff the stopper in the end as far as it will go. The stopper should stay in place even if the bottle is inverted. Note that you can tighten the little nut on the end of the Presta valve to prevent water from coming out during loading.
Set the bazooka on a flat surface, and slide in the filled bottle stopper-end first. When loaded, the presta valve should poke through the hole in the threaded coupler. Slide the washer into the locked position - it should stay in place even if the bazooka is moved or turned upside-down.
Loosen the nut on the end of the presta valve, and attach a bicycle pump with the appropriate presta valve head. Inflate the bottle to between 50-80 PSI. Note that the pressure to which you can inflate the bottle greatly depends on the strength of the bottle. In general, the thicker the plastic, the higher the pressure. Listen for fizzing noises coming from the stopper - hopefully there will be none at full pressure.
Now, simply hoist the bazooka onto one shoulder, and point it at least 5 degrees from horizontal (so that water is covering the bottle's nozzle). Hold onto the handles, and squeeze the brake lever to fire!
*according to Mythbusters the optimum ratio is 1:3 water to air, but that's for vertical flight. Since we're launching on an angle less than vertical, it may be necessary to add more water to cover the nozzle.
Grab a water bottle and fill it about one-third to half full with water*. Stuff the stopper in the end as far as it will go. The stopper should stay in place even if the bottle is inverted. Note that you can tighten the little nut on the end of the Presta valve to prevent water from coming out during loading.
Set the bazooka on a flat surface, and slide in the filled bottle stopper-end first. When loaded, the presta valve should poke through the hole in the threaded coupler. Slide the washer into the locked position - it should stay in place even if the bazooka is moved or turned upside-down.
Loosen the nut on the end of the presta valve, and attach a bicycle pump with the appropriate presta valve head. Inflate the bottle to between 50-80 PSI. Note that the pressure to which you can inflate the bottle greatly depends on the strength of the bottle. In general, the thicker the plastic, the higher the pressure. Listen for fizzing noises coming from the stopper - hopefully there will be none at full pressure.
Now, simply hoist the bazooka onto one shoulder, and point it at least 5 degrees from horizontal (so that water is covering the bottle's nozzle). Hold onto the handles, and squeeze the brake lever to fire!
*according to Mythbusters the optimum ratio is 1:3 water to air, but that's for vertical flight. Since we're launching on an angle less than vertical, it may be necessary to add more water to cover the nozzle.
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Jun 29, 2010. 2:10 PMnoingwhat
says:
Really cool idea! I am going to try something similar, but I am going to try attaching two 2-Liter soda bottles on the back, that way I can pump those up, then launch it off 3-4 times before I will have to pump it up again.
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34
Jun 29, 2010. 2:25 PM
jeff-o (author)
says:
jeff-o (author)
says:
I'm not sure how you'd transfer the air pressure from one bottle to the other, but that could work. Remember, it's a one-time-only trigger and the projectile IS the pressure vessel. It's a rocket-propelled device, not a cannon! ;)
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Jun 30, 2010. 12:02 AMnoingwhat
says:
The two main soda bottles are just going to be put together with a T and I am going to use a small valve connecting that to the launching chamber. I am thinking about maybe making an ible about it. (It would be my first one!), and yes, of coarse I am going to give credit to you for the original idea!
Reply
34
Jun 30, 2010. 7:14 AMjeff-o (author)
says:
jeff-o (author)
says:
Yes, definitely make an Instructable about it!
Reply
Feb 27, 2009. 10:01 AMBoeroBoy
says:
I always tried to design a good release mechanism as a kid. I wish I would have seen this! Rock on.
Reply
34
Feb 27, 2009. 11:46 AMjeff-o (author)
says:
jeff-o (author)
says:
I've built a few launchers before; this mechanism took the best parts of all of them. I'm glad you like it!
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