Building a Rocket! [tut+pics]

Hey everyone I have a new project I am working on and would like to share it here again! Rocketry involves technology/science so I felt this was the appropriate location to post.​

First: This is only for educational purposes, I take no responsibility for your actions reguarding anything shown here. This is and can be very dangerous if not taken serious.

Now that that is out of the way, I will be showing you guys a pretty detailed trial and error of me making a rocket using KNO3 and Sucrose/Sugar. If you have questions please ask them and please know your local laws regarding rocketry. I will update it as I do work to it!
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What you need: ​

1. A good working surface. In my case I used an old glass table we are getting ready to throw away

3. Flat headed trowel or something flat and strong to use like a spatula
4. PVC tubing and end pieces for nozzle and throat (will be shown)
5. Scale and something to measure 1 cup
6. Hammer, large nail or something thin with a flat top for packing, and something to cup PVC
7. PVC glue+paper

8. SUGAR
9. KNO3 or Potassium Nitrate
This is found in "stump remover" and it costed about 4$ for the amount needed to make one batch
10. Tile or something smooth and made from stone
11. ELECTRIC SKILLET! HAS TO BE ELECTRIC!
12. Karo Syrup or any brand similar

13. Water

I am using 1.5" PVC tubing. This can be purchased at Home Depot or Lowes. I also looked around in the tubing section for the parts to make the nozzle and throat. All you physics peeps can check this diagram out. (CLICK)

What is it is a coupling that goes around the outside of the main body. On the nozzle end of the coupling there are 2 components. The first fits into the coupling and has .5" hole where another piece can be screwed in. The final piece is a piece that looks just like a nozzle would look, on one end is the .5" screw in part and the other end is a 1" opening. Use PVC glue to ensure they hold and put them together.

Looking inside from the 1.5" opening:


Looking from the bottom "nozzle" part:


I also cut a piece of PVC for the main of the rocket I don't have the exact dimensions atm but I can estimate between 1.5' and 2'.

Cut a piece of PVC about 1.5" to make the grains for your rocket. This will keep it simple and allow you to simply load the PVC before firing. I lined the inside of the tubing with paper so that once the fuel hardens it can slide out of the mold and into the main build with no fitting issue. I then place this on the tile like so:

Making the Fuel!​

Measure out the following:

400g of Potassium Nitrate
200g of sugar
80g of syrup
200ml of water

Add the water to the electric skillet and turn in on to about 350 degrees and add the water. When the water begins to boil, add the KNO3, sugar, and syrup.



Stir lightly until all components have dissolved.

Now you need to wait until you see the mixture bubbling similar to this:



Begin to stir every 1-2 minutes while it starts to caramelize (become thick and sticky). You should end up with something that when placed on the cool tile, hardens quickly and is not sticky (be careful if you use your hands it is very hot). This is something your finished product should look similar to though, the shades of brown vary greatly.

Make sure it hardens in a relatively fast time once you remove it from the heat, it should not be malleable at room temp.




It will resemble a very hot play-doh. Take enough to fill up the mold and make sure you pack it down good so that there are no air-bubbles inside.



Let it cool for a while and it should slide right out!




I let the motors cool inside of an air tight freezer in an AIR PROOF container, humidity can ruin the propellant because it dissolves easily in water. I took them out today and began to drill the exhaust holes right down the middle of the motors. I made my exhaust holes about a quarter of an inch wide.



The silver you see on top of one of the motors is the propellant from a shotgun shell. That side will be faced towards the very end of the rocket and will be lit first. I did this to ensure that there was a clean light of the propellant and that it doesn't fizzle out. Please be very careful cutting open shells if you take this route. Using the powder from old fireworks will do just the same and be a whole lot safer.

After the wholes were drilled into the middle of the motors, slide them down into the main rocket tubing. I slid a small piece of cardboard down on top of the motors as an interior cap. It will not act like a cap but it will serve as sort of a base for the next part.

When the motors are placed inside of the tubing, they only take up about 1/3 of the space available inside. I want the propellant to stay near the bottom and not rise up to the top of the tube when the force drives it up. I came up with a lightweight way to keep the motors confined to the bottom 1/3 of the tube. Very confusing I know let me explain it better.



In diagram 1, the propellant is sitting at the bottom of the tubing before being lit. In diagram 2, the combustion forces the propellant to the top causing a change in weight and possibly tilting the rocket causing a spin or looping effect. In diagram 3 my solution is to take two sturdy but lightweight items and place one on top of the propellant and one at the cap, in-between, there will be shafts connecting them so that if the bottom item is pressed upwards, it can not go because it is pressing against the cap.

After doing some recon around the house for something sizable I found 2 foam golf balls that are light weight and fit into the tube perfectly. I also found crafting sticks (the long wooden poles that are in the back of Walmart).





I just cut the sticks to the correct size of the tubing and glued them into the foam balls. After this I stuffed it into the tubing also.



The last thing I did was place and glue the cap on over the golf ball.

Note: You can use things other than a golf ball, another option is something like aluminum foil that can get a solid fit in the tubing while staying light weight.



That is the roughly completed model. Everything on the inside it pretty much ready to go other than a fuse.

Optional Protection Layer

I was not satisfied with just the cardboard platform blocking the golf ball/stick combo. I came up with a little way to help reduce the heat transfer.

On top of the cardboard I placed a VERY thin layer of quick-dry. None of it fell through to the propellant because of how closely I cut the cardboard to the side of the tubing. This layer is to absorb any water from a THIN layer of cement.



I did not use close to all of it, just enough to create a barrier to absorb any moisture that gets through a second piece of cardboard. On top of the second piece I added a small layer of cement then let it dry.





More to come!

PLEASE READ THE WARNING AT THE BEGINNING AND BE VERY CAREFUL WITH THIS STUFF!

 

Nice build so far man, can't wait for the rest.

 

You must really love building stuff.

(Your comp and now a rocket)

 

Ooh another interesting build by you! I look forward to seeing hows this turns out You post alot about it too, which is good.

 

Updated + added video of propellant.

 

Good update I'm not sure if you know about this or not, so I'll type it anyway. If you use spray Teflon, it creates a very slippy layer on the rocket, making it more aerodynamic. Are you installing a parachute inside it so you can retrieve it, or are you just going to let it go? If you are using a parachute and getting it back, if you make the rocket brightly coloured it will be easier to find.

 

=) thank you, I am planning on just letting this one go, I do have an idea on setting up some kind of parachute system that I am sure will work but I think for this first test I just want to see if it actually works lol (I'm having some doubts). If I can get it to fly within the next 2 or so attempts, I will be adding the parachute to it. And I will be using that idea of painting it a bright color, I was thinking a hot pink that workers use when marking roads.

 

North Korea could take some lessons from this guide. It's very detailed with good pics.

 

LOLOLOLOL nice one


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So uh you know you gotta call NASA and at least tell them you're doing this.. I think if you're going to build a rocket and launch it, it cannot go higher than like 5000 feet or so if you don't tell NASA. I read that somewhere and I'm trying to find the article. Keep at it man.. attach a video camera to the final thing.. that would be legit.

 

Already launched it, pressure was too high and it exploded at about 15 feet up, I know why and am fixing the problem and going to build another one. Ill post the vid later. Also, I work for NASA =p. You need to contact the FAA and ask what the guidelines are for amateur rocketry in your state/city.

 

Doesn't sound good... How much have you spent on the rockets so far? Including making the fuel, the shell etc.

 

Like 20 buck lol, its really cheap to make.