Water Rocket Forum

A few years ago someone on our team took a cellphone photo of a new water rocket toy they saw in the store, and it was saved with similar stuff and quickly forgotten. When cleaning up the clutter we discovered the picture and (finally) got to check out the toy. We found a really corny video commercial online that shows how it worked. It has an interesting design with the pump built into the rocket itself, and a release mechanism controlled by a lanyard. It's not clear how the release works from the video, but the method of operation shows the kids tossing the rocket into the air and as the rocket reaches the end of the lanyard and it pulls off the nozzle and the rocket launches at that moment and the water is released.

We need to investigate how this works, because it may be an effective staging mechanism or method of air-starting an engine on a boosted rocket. Check it out:

[youtube][/youtube]

Hmm, going to have to build this and see if it works.

So we're not the only ones with rocket plans sketched on every piece of scrap paper in the house!

The only problem I could possibly see with using this as a staging mechanism would be the force required to separate them. It looks in the video like the rocket launches after it reaches the end of the lanyard. The sudden jerk releases the rocket. Unless I am mistaken, a water rocket doesn't have a sudden jerk phase.

Or am I being a sudden jerk? I am too tired to be thinking about this right now lol!

DogLover wrote:The only problem I could possibly see with using this as a staging mechanism would be the force required to separate them. It looks in the video like the rocket launches after it reaches the end of the lanyard. The sudden jerk releases the rocket. Unless I am mistaken, a water rocket doesn't have a sudden jerk phase.

Or am I being a sudden jerk? I am too tired to be thinking about this right now lol!

If we could figure out how the toy thing works, we could then know if the jerking force is substantial, or if some motion we already have to deal with could be used to start the thrust. For example, if the action of a booster falling off were good enough to make the thing fire up, then someone could make a rocket with strap-on boosters that would be a true "multi stage" rocket, because the core/sustainer would start firing only after the boosters burned out.

Stopping the video, there's clearly two latches on opposing sides of the nozzle on the rocket. Spring loaded bars in the plug side that are pulled back by the tether could easily be the answer. I think we'd have to look for separation force to come from wind drag either on a chute or the booster. I figured drag on the booster coupler[vimeo][/vimeo] sleeve might work, but a chute has the possibility to exert more force.

Ok, I think I am ready to build this.

That looks like a great toy.
Good luck with the rebuild bugwubber!

While the glue is curing on the plate, here's a demonstration of how I envision this working.
Can't get this to play on my phone so here's the YouTube version

[youtube][/youtube]

U.S. Water Rockets wrote:A few years ago someone on our team took a cellphone photo of a new water rocket toy they saw in the store, and it was saved with similar stuff and quickly forgotten. When cleaning up the clutter we discovered the picture and (finally) got to check out the toy. We found a really corny video commercial online that shows how it worked. It has an interesting design with the pump built into the rocket itself, and a release mechanism controlled by a lanyard. It's not clear how the release works from the video, but the method of operation shows the kids tossing the rocket into the air and as the rocket reaches the end of the lanyard and it pulls off the nozzle and the rocket launches at that moment and the water is released.

We need to investigate how this works, because it may be an effective staging mechanism or method of air-starting an engine on a boosted rocket.

So if you think of the water rocket as a launcher, and the cap as a projectile, it becomes clear why this toy may have failed! Seems like this idea is a variation of that Mattel 2 stage water rocket that used metal clips on a string. Except in this case, the kid is throwing the rocket instead of using a first stage.

That is a very nice little video which demonstrates the function of it.
I'm looking forward to see the final "launcher".
Cheers
Julian from Raketfued

Thanks!

I think I am going to mount this on a launcher first for testing.

Current status:

Alright, I was a little worried about what I was going to use for hinge pins but I've decided to try pieces of a broken fishing pole.

Some positive developments, with the pins in place the latches self release when they are not held in place which is what I was hoping for.
Locked Released

That looks good so far.
Do you use polish to make it waterproof?
Cheers

bugwubber wrote:

U.S. Water Rockets wrote:A few years ago someone on our team took a cellphone photo of a new water rocket toy they saw in the store, and it was saved with similar stuff and quickly forgotten. When cleaning up the clutter we discovered the picture and (finally) got to check out the toy. We found a really corny video commercial online that shows how it worked. It has an interesting design with the pump built into the rocket itself, and a release mechanism controlled by a lanyard. It's not clear how the release works from the video, but the method of operation shows the kids tossing the rocket into the air and as the rocket reaches the end of the lanyard and it pulls off the nozzle and the rocket launches at that moment and the water is released.

We need to investigate how this works, because it may be an effective staging mechanism or method of air-starting an engine on a boosted rocket.

So if you think of the water rocket as a launcher, and the cap as a projectile, it becomes clear why this toy may have failed! Seems like this idea is a variation of that Mattel 2 stage water rocket that used metal clips on a string. Except in this case, the kid is throwing the rocket instead of using a first stage.

A lot of these toys fail because they are just not very impressive in real life. They put all kinds of safety devices in them to prevent them from hurting people, and that inherently causes them to perform terribly. They limit the pressure, which hurts the maximum altitude. They restrict the nozzle, limiting the speed it will fly. The two things that would "wow" kids, are crippled.

We have a collection of water rocket toys that people have sent us over the years, and you'd be amazed at the lengths they go for safety. One of them even has this weighted pendulum inside that prevents the launcher from activating if the rocket is not held within about 5 degrees of vertical.

Plus, with people us demonstrating how to make better water rockets on YouTube and here on the forum, kids probably just make their own water rockets and skip buying the overpriced toy.