Triple Soda Bottle Water Rocket Launcher

We knew we wanted to try water bottle rockets -- with eggs as passengers ("Eggstronauts") -- and there are a number of launchers available. This one had good reviews and the option of firing off as many as three at once. Plus the seller responded immediately to my email asking whether he could ship quickly. It was the end of the school year and kind of a last minute decision to try this, and he promised to ship it out right away Priority Mail. Sure enough it arrived on Monday ready to go, and we followed the website video for the limited assembly needed. Also mined the website for information, techniques, and invaluable fin templates that I printed out and brought to class. Could NOT believe how that class of kids pounced on this project, they could NOT wait to get their hands on the bottles, the fin patterns and foam core, and all the other raw materials for nose cones, decorations, etc. They came up with some crazy ideas that were way outside the box, and I was eager to see which if any of them would fly. Took a bicycle pump with a built-in pressure gauge and pumped the bottles up to 80psi and one by one they blasted to the skies to uproarious cheers and applause. The launch pad really should be staked down -- we were on pretty tough ground so I could only pound two stakes in, and that was the minimum I'd use. Even though the design is simple and a little homegrown it worked flawlessly for all of our launches and I don't really see how it's likely to break under repeated use. PVC pipe is solid, they cleverly flared the pipes so no O-rings are needed, the mechanism is simple enough that any repairs would be straightforward and we got in the groove and fired off rocket after rocket without mishap. We had a blast of a day, and everyone can't wait to try it again. Thanks for providing not only the launcher but the website support -- it makes all the difference.

While the rocket launcher did a great job of launching the Rockets it requires some changes in order to do so. The weight of three bottles causes the launcher to tip, I had to build a wooden base to better support the structure. The teeth that hold the bottle in place with the ring don't always fit properly and cause you to have to manually pull the ring down instead of using the string to produce a launch. The string also has to be replaced as it was causing cuts on my students hands. Overall, the structure of the launcher does the job, you just better be handy at fine tuning the little details that allow for an easier launch experience.

cool to watch...kids loved it. However it is difficult to get the bottle to stay in place before launch. Probably human error, but we just hold the bottle down.

The instruction sheet is not very clear and neither it nor the website specified exactly how to load the rockets and set them off. It would be good to have step by step directions. Otherwise, it works great!

With all the dry fields around our home, we chose a water rocket over combustion models. We ordered the assembled item and mistakenly received a box of many parts. One email to seller and the assembled model arrived in two days. Just screw the launch towers into the base, and it's ready for action. We used 2 liter soda bottles, set the air compressor for 90 psi, and had amazing launches. We cut the bottom out of one soda bottle and taped it to the base of the launching bottle. Tail fins added a lot to the stability of this elongated vehicle. We even twisted the trailing edges of the fins and got spiraled flights. Filling the launch bottle 2/3 full of water got us the best results. We used a half lemon for a nose cone, and didn't even tape it in place. The spout of the bottle slides over the launch tower and comes to rest against a bulge in the pipe. The twist tie assembly should be positioned smooth side out, because the projections actually hold the bottle in position while it's pressurized. The sliding collar holds the twist ties against the bottle until a tug on the string pulls it away. That lets the ties spread apart and release the rocket. These rockets get serious altitude. The instructions caution you against putting your face over the rocket...duh. But you have to be even more careful when the vehicle returns to earth. It took over 4 seconds for the return flight. If I remember my physics correctly, 1/2gt^2, that's a couple hundred feet in the air. The lemon nose cone often exploded into lemonade on impact. At times, it left a 2 inch dent in the lawn. Keep the audience under suitable cover. Simple as it is, this launcher is tons of fun and works as advertised. It's amazing how sturdy the bottles are. With two taped end to end, the first bottle develops a crumple zone that protects the rest of the rocket. Great fun.

I had some problems when the pressure was higher than about 50 psi that the collar and bottle would inch upward and the bottle would start spewing water through the bottle opening. I tried to tighten the zip-tie collar, but I have continued to experience less than total happiness. Fortunately the higher pressure was not needful to my classroom experiments, as anything much higher than 60 psi is a safety concern in larger groups of students.

I used this for an 8th grade science project. The students built bottle rockets and we used this launcher to fire off the rockets. The launcher was super easy to assemble...no tools required if you are relatively strong (a wrench may be useful, however) as you need to screw in the three bottle posts. Each post had pre-teflon-taped threads for an airtight seal, which was a peasant surprise. In other words, assembly is a breeze! This launcher held up very well. We launched over 100 rockets and there was no sign of this product failing or fatiguing due to use. I would highly recommend this product!

some 2 liter bottles don't fit well. well constructed