Baby Gender Reveal Water Rocket - Help with Ideas

[SK77X]

Hi Everyone,

First time poster, and completely new to water rockets, so pardon my ignorance, inaccurate terminology, or poor understanding of rocketry.

So, my wife and I are expecting, so I wanted to do something a bit different to the traditional ways of revealing the gender of the baby. Are some deep thought I somehow landed on the idea of a rocket of some sort for the reveal. Since I had no experience with this, and didn't want to chance any issues for the reveal, I looked for rocket kits on Amazon. I ended up going with the 4M Water Rocket kit. I watched a few YouTube videos, seemed simple & dependable enough, so I bought that.

So next up is deciding how to incorporate the gender reveal (i.e. finding a way to show a blue or pink color). Here's the options I thought about:

• Parachute: I had seen a few videos of water rockets with parachutes attached, so I thought I could maybe spray paint one of those red parachutes, so that when it deploys my family members would see either a pink or blue parachute. This seemed like a sensible and safe option, and one that would be fairly easy to pull off. The only thing this idea lacked was a sense of flair. (I know, as if shooting a rocket isn't enough, I still wanted a bit more panache)
  
• Confetti: So the parachute was simple, but a tad boring, so I thought, what about if I packed some colored confetti with the parachute, so that once it deployed you'd see a shower of confetti to reveal the gender. That sounded like a great idea, so I bought some confetti to test out, but in the back of my mind I had a feeling this might not work well. I was right. Upon testing it, the problem with the confetti is that when you're looking straight up to a bright sky on a sunny day, the sunlight washes away the color of the confetti, and the wind blows it away so you don't end up with that 'shower of confetti' finale you had played out in your head.
  
• Colored Powder: Now this idea seemed like a cool one! Put a small cup of colored powder on the top of the 2L bottle, cover it up with the bottle nose cone, and once it reaches apogee the nose cone naturally slides off, the rocket rotates at it begins to fall and the powder comes streaming out in dramatic fashion. Heck yeah, great idea!! ...... Nope. I spent a good amount of time testing the powder idea, but it never quite worked perfectly. Some times the nose cone wouldn't slide off because the air pressure would keep it sucked onto the small cup holding the powder. Other times the nose cone would fall away but the majority of the powder stayed stuck in the cup until the bottle impacted the ground and then the powder was visible. I tried it without the nose cone, and that did allow some powder to stream out during ascent (good enough), but without the nose cone there was so much drag the rocket didn't get to that awesome altitude afforded by the bottle nose cone.

Here's where I need your collective help. What I'd love to happen is either:
a) powder streams from the rocket as it climbs, so it looks like pink or blue smoke from the rocket,... or
b) the powder is fully dispersed at apogee to create a dramatic scene.

The challenges are:
a) I would love to somehow keep the impressive altitude that comes with using a bottle nose cone.
b) I would like to have a good amount of powder (e.g. at least 1 cup's worth) so that the reveal is visually dramatic

.. ..

Included are 3 photos.
- One is the rocket with a cup placed on top to show what basic form I had created to hold the powder. As I stated, the only way this cup idea worked was without the nose cone, but that compromised rocket altitude.
- The second photo is the rocket, with cup and nose cone. This form still achieves great height, but the powder doesn't disperse much (or at all some times).
- The third image is a 'new' idea I've been thinking through. It involves drilling holes in the cup that will hold the powder. I've already tested how well the cup holds the powder with these holes, and the majority of the powder remains in the cup (i.e. the powder doesn't keep trickling out since it isn't liquid). My thinking here is, as the rocket launches, the pressure of the air will help push the powder out these holes/vents, thereby creating the stream of powder as the rocket climbs. The downside to this concept is of course without the nose cone there's plenty of drag.

I've come up with another idea, one that in theory will allow the nose cone to be used, and still provide the streaming powder. This idea involves sticking two or three toilet paper rolls (or other slender plastic bottle) to the side of the 2L bottle (as boosters). Seal the bottom of the rolls, and put holes in the rolls (similar to the cup). This way the head of the rocket still has the bottle nose cone for aero efficiency, and the holed toilet paper rolls filled with powder still allow for the powder to stream out.

I haven't been able to test this drilled holes concept though, so as of right now I have no clue if the air pressure will even push the powder out of these holes.


So.... after that novel, I was hoping to see if anyone had any ideas for making this work at all, or better, or any sort of tips/suggestions based on experience. Anything that might help make this work would be greatly appreciated as I'd love to put on a fantastic show to reveal our baby's gender!! In the end though, whether it works perfectly doesn't really matter, but while I still have a couple of weeks left until the reveal, I'm going to keep trying to make this things go as high as possible, and stream out as much powder as possible.


Thanks for your time and any help!!

 

[Funkworks]

Well first off congratulations!

I know nothing about water rockets, but on a typical low-power rocket, one could probably fill the upper tube with some colored flour and see a cloud puff when the parachute ejects. That's as far I would go personally, but others here might have more elaborate ideas.

For better or worse, I'm pretty sure there's a rule against confetti. Cheers!

 

[BABAR]

Congrats.

I was thinking a text message would be easier........

If you MUST use rocket(s), I was thinking the Paul Revere technique, “one if a man, two if girlee “

 

[Zeus-cat]

This forum deals mainly with black powder motors and other motors that burn fuel. Water rockets is not something most of us have experience with, but I'm sure there are a few.

You may want to look for a water rocket forum. I think there is one in Australia as they pop in here once in a while and post things. I found one: https://www.waterrocketforum.com/ EDIT: I see you posted the same message there.

And congrats and good luck.

 

[NOLA_BAR]

Hello, I just saw your post. I’ve done a lot of water rocket designs for my son’s scout pack. First let me say that the reliability of a water rocket to perform as expected is well... unreliable. Not sure you want to have something as important as a gender reveal done this way. That said for the scouts I wanted to have a water rocket perform similar to a low power model rocket, mainly with a reliable recovery with a parachute. I’ve attach some pictures of what I did, it was reliable almost all the time.

It is called Nose-over at Apogee (NOAA) deployment.

Get a pool noodle and cut off a 6in length. Give it a nose cone shape using a utility blade etc. and make sure it fits snug on the bottle cap portion of your nose cone piece.

Drill a small hole in the cap, thread about 24”of string through the cap and the hole in the pool noodle.

At the end of the string add about an ounce of weight. Hex nuts work good. The weight and string will go to inside the noodle hole before launch. At Apogee this weight tips out and pulls off the nose cone and deploys the parachute.

Make a knot above and below the cap. Attach the other end of the string to the water rocket with gorilla tape. Attach a parachute.

Hopefully it will also spill out all of your colored powder.

Congratulations and good luck!

 

[NOLA_BAR]

Actually looking at my photos I used about 36” of elastic. But string should work fine.

 

[BABAR]

Hello, I just saw your post. I’ve done a lot of water rocket designs for my son’s scout pack. First let me say that the reliability of a water rocket to perform as expected is well... unreliable. Not sure you want to have something as important as a gender reveal done this way. That said for the scouts I wanted to have a water rocket perform similar to a low power model rocket, mainly with a reliable recovery with a parachute. I’ve attach some pictures of what I did, it was reliable almost all the time.

It is called Nose-over at Apogee (NOAA) deployment.

Get a pool noodle and cut off a 6in length. Give it a nose cone shape using a utility blade etc. and make sure it fits snug on the bottle cap portion of your nose cone piece.

Drill a small hole in the cap, thread about 24”of string through the cap and the hole in the pool noodle.

At the end of the string add about an ounce of weight. Hex nuts work good. The weight and string will go to inside the noodle hole before launch. At Apogee this weight tips out and pulls off the nose cone and deploys the parachute.

Make a knot above and below the cap. Attach the other end of the string to the water rocket with gorilla tape. Attach a parachute.

Hopefully it will also spill out all of your colored powder.

Congratulations and good luck!


View attachment 426591View attachment 426592View attachment 426593

Looks workable.

I am not sure I would want a metal hex nut potentially being the first part of my rocket to hit something.

Assuming the chute deploys okay and the shock cord lengths are appropriate, it SHOULDN’T be the first think to hit, and the chute will slow it down.

Possible failure modes include

1. Failure of chute to deploy. Rocket comes in ballistic. Even worse, with this design it is possible the hex nut bundles will still have less drag than the rest of the rocket, so it comes out of the front and “leads the pack” to the ground. Not going to be good for any bystander or vehicle it may contact,

2. Failure of cord. Even if chute DOES deploy, unless you have electronic deployment, will likely occur a bit before or after apogee, so the rocket components will have some forward velocity. Need a really stout cord to hold that weight on, if it breaks you have a cluster of hex nuts falling from altitude, likely too small and moving too fast to see and avoid.

There are likely a number of ways to “safe” this, one is a two part foam section with the weights having a section of protective foam around them, so if fecal turbine interaction occurs, at least the force is spread out over a larger surface area.

 

[NOLA_BAR]

Yes I would not do this project again.

“First let me say that the reliability of a water rocket to perform as expected is well... unreliable.”

This was a scout demonstration project over a year ago. Nobody would allow us to launch Estes type rockets. I went back and looked at the design and for the nose cone (the green part) I used a larger diameter bottle. It rested on some felt pads that I attached to the lower rocket body side. You can see those in the first photo above. The launch acceleration kept it on until it would flop off at Apogee. The scouts loved it, and I enjoyed doing it, but it was a major PITA.

 

[SK77X]

Thank you so much NOLA_BAR for the fantastic post, especially including photos!

Also thank you BABAR for the additional thoughts on safety.

NOLA_BAR, I believe your idea of using weights to help detach the nose cone clear of the rocket body will be exactly the sort of solution I need! I'm still undecided on a parachute (don't really need the rocket again and the few bystanders we will have will be safe as this will be done on a rural property).

One question though. How did you ensure that the weights would actually come out of the pool noodle chamber? Isn't there the possibility that the weights will get stuck inside the noodle and therefore not provide the weighted force to yank the nose cone off?

Thanks again for the invaluable help!

 

[NOLA_BAR]

Thank you so much NOLA_BAR for the fantastic post, especially including photos!

Also thank you BABAR for the additional thoughts on safety.

NOLA_BAR, I believe your idea of using weights to help detach the nose cone clear of the rocket body will be exactly the sort of solution I need! I'm still undecided on a parachute (don't really need the rocket again and the few bystanders we will have will be safe as this will be done on a rural property).

One question though. How did you ensure that the weights would actually come out of the pool noodle chamber? Isn't there the possibility that the weights will get stuck inside the noodle and therefore not provide the weighted force to yank the nose cone off?

Thanks again for the invaluable help!

As for the weights, I can’t guarantee they will always fall out. For every launch that I did they actually performed as planned. The nose cone was from a larger soda bottle, a 2.5 liter that I found at dollar tree, so it sat loose. It rested on those felt pads that I cut in half-moon shapes then glued onto the sides of the 2 liter bottle (low-temp hot glue). The acceleration of the launch kept it down till Apogee when it would tilt over and flop off.

As much fun as it was, maybe another idea for a gender reveal?

 

[RainierWolfcastle]

My suggestions:
1)Paint the bottle opaque, and colour the water inside. Have to have a play with how intense you need to get it to show up, might be able to mix coloured chalk powder in the water to make it stand out more? I’m sure there is a range of water based paints and dyes that would be options, those rockets fly on nearly anything that’s a pourable liquid.

Or

2)Use a small Estes starter kit with an Estes black powder motor, and pack coloured chalk powder in with the parachute. It’s sometimes done to help with tracking small rockets, the ejection charge will give a good dispersal and you can choose motors that don’t go too high. Added bonus, suddenly your starting out in model rocketry!

 

[PedroTheRocketNerd]

I would personally agree with the recommendation to use an Estes rocket. The motors have a built in pyrotechnic charge to pop the parachute out, which could easily be used to eject some colored powder for the gender reveal. Much simpler and more reliable than relying on gravity to *maybe* pull apart the halves of a water rocket. In addition, starter sets can be had for $20-30, so the cost would not be terribly great. Whatever you try, though, I wish you clear skies and best of luck.

 

[86mustang408w]

I would dye water, but paint the rocket so they can't see it. When it goes up blue or pink water comes out. Another cool thing is using the ejection event with colored powder, when the chute opens an excess of blue or pink powder comes out.

Go buy a cheap Estes Olympus, you could fill half the tube with colored powder over a water rocket. Use a small motor so they can see it. Or get an overly large chute in, once again pink or blue.

 

[Hobie1dog]

to the forum. Congrats to you both.

 

[OzHybrid]

Have a look at the AirCommand site. George has launched using Diwali colour as a propellant. Very spectacular. You can test the principle using flour and swap out with Diwali colour on the day. ( Holi powder) George would be able to give you nozzle sizes and pressures. There is NO water used for this.......
@air.command
Here's one video of it in action...

 

[Spitfire222]

Guys, please check the date of a thread before replying. This one is from three years ago. Presumably the OP knows the gender of the child by now, who is likely approaching three years old.

 

[OzHybrid]

Ha ha..... Oops.
Information for the next requestor.....