5' PVC Missile-How to Build High Power Rocket from Scratch: Part 5-Casting the Fuel

[WizzBang75]

I think your tutorials are great...please keep up the great work. I've just started with all of this and you've made many things clear and comprehensible so I am already producing predictable results. Thanks again!

[koolboyameer]

@rocketmanbkk here in UAE (dubai) potassium nitrate is very expensive !

can u pls tell me the exact amount of KNO3 needed for making 5 pieces of flexi fuel !????

[uberLejoe]

also a cap like lid for the engine with a metal rod through the top would be best for them :)

[Dongskie2]

Hi RocketmanBkk I was wondering how the sample engine you made (from the residue off the pan) burned at one direction only, it was like it has a nozzle already.

[thehappyinfidel2011]

So your doing this in your kitchen and using your wifes pans when she's not home? Kids in the other room?

[rocketmanbkk]

@thehappyinfidel2011 : Actually, wife is very supportive of my hobby. I have my own pan for rocket fuel and the kids are upstairs. Thai houses are all concrete so I'm not worried about burning the house down. Though, I do not recommend this method if an outdoor option is available. : )

[thehappyinfidel2011]

@rocketmanbkk That's great it was meant to be humorous. I have a large dose of mad scientist in me too. Why else would I be watching? ; ) Have fun!

[debrexbeta]

wow... ur gonna make me some?

[10163me]

whare can I get the core rods

[SuperDriverDan]

nice ! :-D



[Libertusss]

05:30 You've got some brave ants there Rocketman!

[sedwarg]

how come it's so hot? Is it still from the pan or is there some sort of exothermic reaction?

[rocketmanbkk]

@sedwarg : r-candy is VERY, VERY hot from the pan. Be very careful in handling. I have burned my finger tip upon touching it. It may be an exothermic thing with the aluminum coring rods as well.

[jehfatpanda]

shit, my wife might be watching this right now.

[punisher102938]

i know that it would most likely kill you.. but that looks yummy!

[chords1983]

Long time follower of Richard Nakka, but it's been many years since I have been tinkering with rockets and motors. These videos got me all excited to get back to it!

[Gabesly]

ok im 13 and new to this, what is a bates grain?

[rocketmanbkk]

@Gabesly :BATES Grain

Google Richard Nakka

A google search will teach you a lot.

[ji6vKYW1]

it looks like oatmeal

[TheFyroPyro]

if those were smaller the would be bad ass stars! XD

[jmar1371]

Bates grains that short will provide a very regressive thrust curve.

[rocketmanbkk]

@jmar1371 : I make sure that the grains are at least twice the length of the web in order to maintain a theoretical neutral burn. I'm very familiar with burn profiles and the reason I keep them at this length is to get immediate liftoff without having to add more fuel because I don't want to have to enlarge the nozzle throat because the next size washer available here is too big. I want to keep it within 250-275 grams of fuel.

[jmar1371]

@rocketmanbkk The formula for calculating a neutral grain is L = 1.5D + .5d. Those grains look short.

[rocketmanbkk]

@jmar1371 : Thanks for your input.

[transslucide]

Hello, I follow your videos from a long time, and watching this again I ask me why don't you try to make a less liquid r-candy (to cook this a bit much) to have a best burning rate ? It's right, it's quite difficult to case, but it's better if you find a good way to put it as you want in your motor. I know really well that's dangerous, but if we make it safe, there's not any problem.

Sorry for my bad english.

[rocketmanbkk]

@transslucide : this fuel is purposely made this way for ease of casting as well as safety. Never had a CATO with flexi fuel. Standard R-candy will dry brittle and will crack easily making for a dangerous fuel.

[zachtuck2009]

can you eat this

[rocketmanbkk]

@zachtuck2009 : Of course not. After all, it is rocket propellant.

[zachtuck2009]

@rocketmanbkk ok so y is the name rocket candy

[rocketmanbkk]

@zachtuck2009 : Over the years sugar propellants have been called rocket candy simply because of the sugar composition in the formula. It is not edible. KNO3 is a preservative found in foods and toothpaste but only in minute portions. A large ingestion of KNO3 is not safe.

[zachtuck2009]

@rocketmanbkk k now this was a good vid but post that when you post the vid

[SoopaMario1]

Awesome vid

[cantescape1987]

Great video, just one question....What is the diameter of the rod you used to make the core. or what size do you suggest for a engine like this?

Thanks,

Cant

[rocketmanbkk]

@cantescape1987 : This particular design uses a 10mm core, same size as nozzle throat. 1/4 core will work just as well. Just make sure your igniter wire is small enough so the it can come out easily during ignition.

[fly2000jtb]

Do you have a video with written candy fuel portions? potassium, sugar, etc... also what if you use ammoniun nitrate? would it work or blow up? we have sodium and potassium nitrate as well, which one of those work better? Joseph T fly2000jtb

[Olao999]

I have a question: When i try to make r candy, after cooking, i let it cool, but when cool, it still remains soft, not hard rock candy, and when I try to ignite it, it ignites for short periods instead of burning equaly. Sorry for my bad english, and thanks.

[TheWisey1234]

where can i get the r-candy from cheap

[gluestick0808]

nice videos - they have been very helpful

[jmar1371]

Suggestion... Adjust your length/diameter ratio. Bates grains as short as these will yield a very regressive thrust curve, even worse with an ablative nozzle. L/D ratio of ~2/1.2 will yield a neutral curve with a graphite (non-ablative) nozzle. Longer grains will yield a progressive curve.

Go slightly longer with an ablative nozzle, to keep the Kn ratio relatively constant.

[rocketmanbkk]

@jmar1371 : Nozzle is steel washer: Non-ablative. I keep the grains shorter to keep the amount of fuel down and the KN within a good safety margin. My launches with this configuration are actually way to high for the size of fields I have available at this time. I usually try to keep the length twice the web thickness to keep a more neutral burn. I prefer a non-ablative nozzle.

Thanks for your input though.

[rocketmanbkk]

@jmar1371: I'm very aware of the progressive, regressive thrust curves. This nozzle has a steel washer, non-ablative.  I keep the grains shorter to keep the KN lower and weight lower.

[jmar1371]

@rocketmanbkk I have no idea why this thing posted my comment twice. I made it over a month ago, and you already responded. There's a maximum volume loading available in any given motor casing. Short or long grains does not really affect that, only the resulting curve.

[panzuman]

hey i really have been wanting to see a new rocket launch and i havent seen anything from you in a while. p.s. your rockets are the BEST! i reccomend flexi fuel to evryone!

[farshad94abedi]

may i ask how u came to this knowlage? lol

[amarbir22]

dude i went to get saltpeter, bt dint found it newhr, tried CanadianTire(a canadian hardware store), Shoppers Drug mart(pharmacy) and Reno Depot.

Help me find kno3, i live in canada

[CAIDMASTEROFPYRO]

ebay

[tecnobrains]

@amarbir22 look for something called stump remover. i don't know if they sell it in canada, but Green Light brand is pretty pure

[newman015]

@amarbir22

You can buy it easily on Ebay

[amarbir22]

man u made it look so easy, i am gonna try it

[rocketmanbkk]

On the contrary. R-Candy is rocket propellant made with any kind of sugar or sugar combination ie, sucrose, glucose, dextrose, fructose. That's why it's called Rocket "Candy". Traditionally, r-candy was made with only SU which, when melted is thick, cools and hardens very fast and, when hardened, has a tendency to be brittle.

[mandunya]

@rocketmanbkk Hey I have been following some of the steps provided by yu, and I have come up with great design's for my rocket, the problem is, I haven't got enough time to collect money and buy all the needed parts, if you can help by providing landmarks of store's, or online websites where I can buy some tools to start going for an easy and cheap amount, and by the way of your wondering I am just a kid 10 years old.

[mandunya]

@rocketmanbkk And I will send you some of my plans as a video so you can see, I hope you will like them.

[markov4k]

hey please send me the secret

[huffinpaint]

thank you for your videos!!! im learning alot from them! i hope to become as good as you one day lol!!!!

[gimmeL3mmonz]

that rocket fuel look pretty darn good to eat when u were pouring it in the tubes ^.^

[rocketmanbkk]

I wouldn't eat it though. Don't think the KNO3 is good for u. Even though it is in some foods and our toothpaste. LOL

[gimmeL3mmonz]

this is awesome

[HeaanLasai]

That is by far the best sugar fuel I have ever seen. I'll be waiting for your next vid.

[rocketmanbkk]

KNO3/SU- Pottasium Nitrate and Sugar...and glucose actually. The corn syrup is glucose.

[jackmonkey26]

Is that KN/SU ?

[easylenny]

Wow great tutorials looking forward to the next part of the build. Just ordered myself some KN03 going to practice with some small firework style rockets just to test mix then hope to follow your tutorial to the letter and see how it goes once again thanks for this very clear video

Very COOL!!

[pivotAlper]

Great work!

[twojaythomo]

Great work any chance to do a video on your ignitors and where you position them inside the enigine. Cant wait for the finish and launch

[brandonman94]

Excellent! Can't wait for the next video. Hopefully I'll start on a rocket some time soon...

[AirrowRocket]

Excellent, as usual! Thanks for your hard work. PS, can't find part 4.