Sodium Water Hybrid Rocket? 

Calculating the integral by just cutting the paper and weighing it is hilariously clever. Bravo

From an engineer- weighing the paper of the area below the curve of the graph and then taking into account the per-square weight of the paper is one of the most ingenius methods of doing a definite integral that I have ever seen. The rocket is an extremely cool idea, but I'm almost too distracted by that wonderful old school integration technique to appreciate the rocket.

I haven’t watched Cody in years. The fact that he’s still wearing the chain mail makes me so happy

Making a rocket out of spare parts in a cave. Absolute legend.

The fact that you weighed the graph instead of doing a ton of math is amazing.

Cody still being active makes me so fucking happy. Thankyou for years of great organic content :D

I worked in a pesticide research lab in the 70's, and we used the same weigh-the-paper method to calculate the parts-per-million (or billion) of whatever pesticide we were testing for. We had a PDP-11 and a PDP-12 available to us, but weighing the paper was easier, and just as accurate.

So good to see cody back in good spirits. Seems like he got a new helper

The best of OG RU-vid. Rusty metal, cracked containers, duct tape all over, dodgy camera work... what more could we want? So happy Cody's still going strong!

my man cody has been through some rough shit and still to this day has never dropped effort or quality in videos, he will always be one of the few old youtube legends

It’s been years since I’ve watched Cody‘s lab. Something I used to watch daily and I got immense pleasure out of this. It’s good to see you’re doing well man.

I should add, Cody is a bright and intelligent man - being able to muddle these projects together on a budget is inspiring.

The computer next to Cody whilst he is doing paper based integration is just a paper weight, whilst the paper weight is the computer. Love it

Cody, for flying rockets there’s what’s called the Amateur Exception in the FAA regulations and people regularly build large metallic VTVL and ascending liquid (sometimes hybrid) rockets and fly them. At Black Rock in Nevada the airspace is under a quirky uncontrolled category where the paperwork is particularly easy. The folks at Friends of Amateur Rocketry site in California are great supporters and a launch site as well.

Although somewhat dangerous in atmosphere, this would be an amazingly good idea for galactic fuel. In the vacuum of space it becomes a very stable and renewable resource that can easily be shaped for various purposes

The rocket design looks like something from Fallout. I'd like to see this done with a reaction chamber and a pressure chamber, then the nozzle. Thank you for the video, this was fun!

Watching Cody build things from random pipe pieces makes me feel like I'm on a watch list

weighing the paper was a clever idea, but subtracting the negative piece by using it to tare the scales was a stroke of genius. you truly have the mind of an engineer

i love how even after not watching for ~3 years the vibes of the channel haven't changed one bit

Hey that’s me! Thanks for the autograph Cody!!

cody is sitting in front of a computer that could have done that for him in seconds and instead chose to draw it on graph paper, cut it out, and weigh it haha. this is why we love watching this channel. dudes way of doing things is always so creative

Cody is now becoming a "not technically a rocket" rocket scientist.

I'd advise on using a steam injector that uses the chamber pressure to feed water into the reaction chamber. It will be much more scalable then having to force in water using a compressed gas.

I LOVE HOW CODY EXPLAINS ALL THE MATHS AND HARD PARTS!! I hate most documentaries on youtube because they completely skip over the important stuff, figuring their target audience is both dumb and lazy. Cody explains it how you can recreate it.

I love how Cody greets more and more energetically with every new video. We're super happy to see you too, man.

I like how Cody goes from hand soldering pipes together, to owning a lathe, back to hand soldering. Fits this channel so well.

I thought that the engine would explode since the burn started at the top rather than at the nozzle. Fortunately the sodium was ejected and didn't plug the nozzle. This was a lot of fun to watch and your calculating was bliss.

It will never stop being strangely satisfying to me how much soudium looks like Blu Tack when twisted.

That worked way better than I thought it would! I figured you would have melting problems. I wonder if it would be better to inject both the water and the sodium as a liquid. Or you could fiber reinforce the sodium with something like steel wool. In any case I'm interested to see more!

I feel like i've gone back in time six years or so. Great Job Cody! Jack Parsons would be proud.

Ah man I loved that you used the olden, golden method of just weighing the paper inside your curve to calculate the square area! I always sucked at maths; curve discussions were the last thing I really understood, as soon as it got to integrals I just tapped out - not within my realm of abilities I'm afraid, so I turned to chemistry as my profession - most of the math you gotta do as chemist that works in production is hilariously easy. But once in a while you do have to calculate stuff like this and I absolutely love this clever and super easy method for calculation. It has a long history and it can be surprisingly precise, too.

I love seeing the ingenuity and rigor that you use in the concepts, build, measurement, and explanation of the setup! Weighing the paper is so great, it gave me a visceral sense for what an integral actually is that I never got from all my calculus courses!

The whole "cutting out the traces of the paper and weighing it" to calculate Newton Seconds genuinely blew my mind. It makes total mathematical sense, but I've never seen it used this way. Cutting paper and weighing it is such a nice transmission between mathematics and physics. Perhaps it's a know thing, but it's the first time I've ever seen it, and it just made me understand these types of graphs so much more.

"Now, just because it's made out of pipe, and will probably explode, does not mean it's a pipe bomb. Intention matters." -Cody's Lab 2023. Thank you, Cody, for another amazing video. Not completely done with the video, and I don't know how to suggest this, but I think the optimal setup would have a minimal amount of water come into contact with as much sodium as possible. I'm not sure how this can be achieved.

Excellent show. I love rocket science at any level. Looking forward to see a revised version of this rocket.

I love how you get curious about something and just do it. Then you show us! And measuring the paper weight!? Come on! This is why I’ve been following your channel since 2017. Amazing

Maybe I'm just really dumb but Cody breaking down the math in the charts by weighing the physical object depicting them and interpreting it in real time actually broke my brain

Something to try next time would be to melt the sodium (or NaK) onboard, and inject it with water *and air* (or oxygen) into the reaction chamber. The reaction of water and sodium produces hydrogen, which if ignited would produce much more thrust than the expansion of hydrogen (and byproducts) alone, so an igniter may be prudent. I think you could get in excess of 50 seconds of specific impulse this way. Also, please note that N/s is newtons per second, whereas impulse has units of newton-seconds (N-s). Good luck, and I look forward to your next attempt!

Awesome project! Using a different binder would help, as I see some sodium leave the nozzle unreacted. Also, the reaction is unstable, so maybe an injector that goes through the motor casing would be better.

Bro I have been following you for years, through the ups, downs and sideways. I honestly say yer one of the greatest youtube channels and its good to see you still doing you! Kudos amigo, may you meet your end goals.

Seeing Cody genuinely smile again warms my heart. Keep on keeping on!

A solenoid valve would propably be a good idea for ignition. Could even be pneumatically operated, if you want to avoid electricity at all.

When you added the rod the first thing i thought of, rather than flodding the entire sodium tube with water, you push water through a tube in the middle of the sodium so the water comes into contact with the bottom first, more water comes in from the bottom up, and the sodium reacts upward with the idea of hopefully making the reaction last longer, maybe more controlled

Haven’t seen you in several months brother… love your work! This is just what I needed today

Cody, I want you to know that this is truly one of my favorite RU-vid channels in existence. just a man and his curiosity. So genuine compared to some popular channels that are around today. Really happy to see you still being so excited to make videos for us. Thanks.

The combination of night time POV footage and the fact it's a homemade rocket in an old mine makes this whole video feel like some proper mad scientist stuff from the days of old RU-vid. Excellent and exactly what I've come to expect from Cody.

You might want to use NaK and separate the chamber or you can use granule of sodium to increase the surface area but you’ll need to add a mesh in the nozzle to prevent the granule sodium to pour out. This is a really interesting idea!

An idea to make more of the sodium react might be to put the rocket "upside down". As in, don't have the combustion chamber containing the sodium pointing down, but instead have it pointing upwards, and have the water shoot in from the bottom of the combustion chamber. You could do the same thrust calculations, but just the other way around. You could then have a pipe leading from the top exit of the combustion chamber, which makes a 180° bend and turns down. This should allow more sodium to react, and allow the gases from combusion to exhaust downwards, since that's what'll be producing most of the thrust. Although, this may cause issues with the sodium melting and blocking the flow of water. If this happens, you could have the combustion chamber sideways, and have the exhaust pointing at a 90° angle downwards.

Cody strikes me as a guy who does exactly what he wants. Don't ever change, Brother.

..."I'm not in direct line of sight with the rocket, so I'll be safe... plus I'm wearing armor..." 🤣 That is such a Cody sentence and I love it lol I'm so glad you're back making videos again.

I've never seen this channel before. This video is just really... nice. It's clear, calm, thorough and peaceful to watch.

Thanks for another FANTASTIC video Cody. Man, I love your work bud. So enjoyable.

I used to be a passive viewer on RU-vid, rarely interacting with videos or subscribing to channels. However, Cody's channel was one of the first that I chose to subscribe to. I vividly remember the initial video I watched, where he demonstrated the intriguing concept of making a liquid float on top of a gas. I want to extend my heartfelt gratitude for the years of content you have produced, which has not only educated us in science but also provided endless entertainment. Thank you!

So refreshing to see Cody doing these insane science experiments with common everyday materials seemingly for his and our enjoyment alone. No flashy production or top of the line fancy gear. Just a child like fascination for all to share

I found this channel ages ago and always stumble upon it every now and then and I love it 🤞fun and chill content!

I love that Cody himself didn’t even feel like doing the calculus to get the area under the curve. lol Very tedious to do if you don’t have an exact equation though. I don’t blame him. It really would be easier to just count the squares or weigh the paper. I would have sat there and counted. He’s such a great problem solver. I would have never thought about massing the paper.

Only Cody would wear chainmail as a safety measure 😂

If you want to increase thrust consistency you could use a backsplash approach for the water, and pour the molten sodium in the "combustion" chamber and let it cool around some threads.(Put big beefy threads in the combustion chamber to ensure the sodium doesn't fall out). As the sodium reacts, it should make a "good-enough" splash cone to help it maintain thrust until it is nearly spent. TLDR: Inject water from below(but just above the neck of the rocket nozzle) and aim the injector at the middle. This would likely also reduce the total mass of the engine by reducing its length.

Genius!!! Love it! Thank you Cody for making videos a can watch with my kids! Keep up the good work!

I remember watching you dig that mine. Thank you for entertaining me and many others for as long as i can remember.

Do not stop on this project. This was really cool and I hope to see more. I wonder if you could use a sleeve around the motor and fill it with liquid nitrogen to keep the sodium solid and maybe machine a different center post with channels that the water could be forced into to provide a more efficient burn?

Yes! Always down to watch fresh Cody's Lab! Glad to see you back.

Cool content. Thanks it was very entertaining, I like your authentic personality. The problem I see is that by adding the water to the top of the sodium tube your introducing a lot of uncertainties in the burn. One clog and... boom. Solid rocket engines always burn from the bottom up. Not top down. I'm thinking about using a sodium rod instead of a tube and introducing the water at the bottom of the thrust pipe. The sodium rod would sit on a metal grid stopping it from falling down onto the nozzle opening. As the sodium rod burns it will continuously fall introducing more sodium into the water contact area at the bottom. Just an idea from an engineer from a completely different field. But I have always been interested in rocket design. would love to hear your take on this idea.

Love the vids. I haven't watched in a while but im glad you're still alive!

I got to meet Cody at Opensauce, I had the honor of being in his creator discussion and it was surreal. Cody is 100% genuine and as humble as they come. You can tell a lot of the creators in the RU-vid science area look up to him.

Thank you for always being there for us, Cody. I know life hasn't always played fairly with you but you've always been there for us and especially us old timer viewer have noticed and appreciated your effort. I hope you are able to continue pursuing AND sharing your hobbies with us for as long as you wish to and are able. Thank you for all the work you do in front of and behind the camera.

This is the best video I’ve ever watched on RU-vid hands down. Amazing!!! Please do more of these rockets! Just please be careful with the fuel 😢

Cody, I have two points of advice, 1) pouring the sodium in multiple pours, will result in voids in the material leading to combustion instability. & 2) try creating a pure argon environment to melt and pour the sodium into your combustion chamber to resolve this issue. On a positive note using a threaded rod for the central cavity within the sodium is a great idea as it creates additional surface area for the ignition of the sodium. However, that may be what led to the engine-rich exhaust. (Edit; spelling error.) P.S., If you review the slow-motion footage you can see that the additional surface area introduced by using the threaded rod did in fact lead to excellent ignition of the engine. I believe that the engine-rich exhaust may have been caused due to combustion instability introduced through the use of multiple fuel pours leading to cavitation (voids) within the sodium which in turn led to rapidly varying surface area within the fuel grain creating the instability seen.

This video has an energy I haven't seen from you in years dude. I could be reading to much into stuff but it seems like you've been in a slump and are finally out the other end. Glad to see it😁

I'm not super familiar with rocketry but I bet you could probably cast the liquid sodium into something porous, like a carbon sponge (carbonized white bread, etc depending on ideal density) which would ideally burn away with the sodium but not before it, allowing some level of control on the loss of liquid fuel via wicking. That being said there may be unforeseen interactions between trace chemicals in charcoal that may make other materials preferable. Good luck!

Glad to hear youre getting caught back up man woth youtube. Congrats man, cant wait to see what you come up with next.

Loved seeing the paper weighed to get the area under the curve. That's how I learned to do it back in the day too 👍 Yes, I think having the sodium in liquid form with precise dosing is the way to go. Great experiment, very well and safely executed!

Wow, that episode was epic. I love the real hand to hand science going on here.

when he drew out the force graph and said "were gonna weigh the paper" i thought he was pulling my leg, never been more interested and happy to be proven otherwise, awesome content always comes from this channel and Cody i wish you much more, and good luck. been following for at least a good 5 years, and heres to many more!

You are a genius Cody. Love it

What a cool project! Looking forward to the sequel!

Avoiding counting integral by weighting a paper was absolutely genius idea! XD

Definitely try putting a ring of plates around your bolt in the mold to expose as much of the sodium to the water as possible

What other science RU-vidr gives you alkalai metals, pressurized gases, sketchy hardware store plumbing, improvised measurement rigs, chainmail, and rooster noises, all in the same video? It could only be Cody! 😁

Spectacular project! Thanks for sharing!!

Great test. I would recommend reducing the argon pressure and using a sintered bronze pneumatic muffler for the injector to both better atomize the water stream and also give a longer impulse time to limit the unreacted sodium.

Testing horizontally might also be easier, build a little carriage on wheels or ball bearings and have it press up against a little load cell. The super cheap hx711 based sets will do 10 or 80Hz sampling. Makes the data processing a lot easier, and no weight loss.

Great vid man! Very interesting how you are calculating the specific impulse.. Peace man Rolfie

Great video. Like the problems and your work arounds

I swear Cody is the coolest dude ever. Never ceases to amaze me. Such a badass man.

I love rocket physics, and am extremely excited for this project. I hope you continue it even though the first run wasn't as great as was hoped. I see a lot of folks suggest essentially a structure for the fuel to hold on to, but I worry what kind of weight that adds while also removing possible fuel mass. I think one idea I liked was having the reaction take place with some space before the nozzle. That way any sodium that comes loose into the exhaust still has time to react with some excess water. I think my favorite part of the video is the measuring set up. I would say finding the right damping coefficient would be best though. As if the rocket is shaking up and down it might cause the fuel to shake loose even more. Thanks for a great video Cody

Great video, Thank you Cody!

good job showing some of the frustrating aspects. Thanks for posting.

Alternative fuels like this make for really cool rockets! I'd love to see someone make a functional ALICE engine.

I'd definitely like to see you try with NaK; I thought of that shortly after the start of the video, as it'll allow you to spray it as a mist into the spray of water and get a much more thorough reaction. Though you'll probably have to make your own as I don't think you can just buy it. After you get that working, then maybe you can look into adding injection of pure oxygen to the reaction chamber to burn all the hydrogen being produced to get even more thrust. One more thought I had, that would allow the use of pure sodium, is to melt it first and keep it in a pressure vessel to spray through a nozzle. How to keep it molten is the trick; given that it melts at 98C, ie just below the boiling point of water at 1 bar, what comes to my mind is to have nested pressure tanks - the sodium tank can be in the center, then the outer layer would be the water tank, heated to well above boiling so that the sodium stays liquid, and the water tank will be pressurized by the water vapor. When the reactants are released into the combustion chamber, the superheated water should flash into steam, enabling even better reactivity with the sodium droplets, plus the additional heat should boost thrust? It would be more complicated to build, but it's a thought. Anyway, it's good to see a proper old school Mad Cave-Scientist Cody video again! Thank you :)

The way you calculated the area under the curve blew my mind! Genius!

Awesome! I love the concept. It seems to me your most immediate need for improvement is in regards to fuel mixing. Ideally the only fuel present in the reaction chamber is that to be immediately reacted i.e. the amount of gasoline in a combustion chamber suitable to drive a piston. When you first explained your concept, I assumed you would be using granularized sodium. Seeing the sodium at normal or whatever your ambient temperature was, I can see how this could be difficult, but I think it's your best bet. In my mind the ideal engine would have the fuel mixture entering the reaction chamber in a volatilized state with maximum surface area at a controlled rate that matched that of reaction. I'm thinking two nozzles, one spraying powdered sodium and the other water. Anyway, love what you're doin man, don't let your reaction product exceed the escape possibility of your reaction chamber.

Hopefully its not too expensive for you to retry this because i definetly want to see a part 2. Especially after you already finished the rocket design.

I think if you add some features to help hold the sodium in place, kind of like heat sink fins on the inside of the combustion chamber, that should help reduce molten sodium getting expelled. You might also be interested in Thunderfoot's exploration of sodium as a rocket fuel, where he's using microjets to improve control of the combustion vs solid sodium. You might even be able to make superheated steam and just shoot the sodium into that, which I imagine would be a ludicrously efficient burn!

I am so glad to see you get back to the weird (out of the norm) since stuff. You have a brilliant mind thanks for sharing it with us.

Good man, I did enjoy your work, keep it up.

Casually has sodium in inventory

Good to see Cody's alive 😂 great vid, don't give up... please

Even when it doesn't work out as expected it's epic! Great stuff!

When I think of channels I have consistently watched for my ten or so years of RU-vid, yours is the only one that really springs to mind. Keep it up!