Gyrojet the Spinning Rocket Bullet

To sign up for the event, just submit a brief presentation of your project.
Learn more on the website: event.3d.ru/
Follow me on Instagram: / integza
Support me on Patreon: / integza
Paypal me:paypal.me/jgomes1992?locale.x...
Discord: / discord
Reddit: / integza
3D models:www.thingiverse.com/thing:508...
Ceramic Printer:tethon3d.com/product/bison-10...
Bronze Filament:shop.thevirtualfoundry.com/co...
@taofledermaus : • GYROJET Rocket Guns - ...
@Backyard.Ballistics : • HOW I've Remade the 19...
#rocket #bullet #3dprinted

[@Backyard.Ballistics]

Well done! I'm really honored you took my suggestion seriously! 😃 On a more technical note, I think the nozzles were falling apart during the burn, and that caused most of the inaccuracy. The ignition leads might have interfered a bit as well. However, I came to the conclusion that differently from bullets, spin alone is not sufficient to stabilize a rocket. Complex rotational instabilities appear as the motor burns that cause the rocket to wobble wildly. After publishing my original videos I found out that even some space missions were lost due to a spin stabilized upper stage wobbling out of control. I think that fast rotation, that was supposed to be the Gyrojet's greatest asset, ended up being its biggest curse.

[@suomynonAyletamitlU]

I agree that spin stabilization with a rocket is a hard ask, but also, I don't think you'll ever achieve spin stabilization with the setup shown here. Because the shell isn't a tight fit in the tube, it's easier for the shell to slide forward than it is for it to rotate--just consider the surface area of a line down the tube compared to the surface area of a single revolution around the rocket's axis, much less the many, many revolutions you are looking for for spin stabilization. And as long as the rocket isn't spin stabilized in the tube, if there is any room for it to bump around inside the tube and end up with weird momentum coming out the end of it, it will. Frankly, what this rocket bullet wants... is to actually be inside a close fit, closed, rifled gun barrel, with the the barrel providing part of the spin, and the closed nature of the tube containing the rocket thrust to help overcome the friction and impart spin. Only once the bullet leaves, going in a straight line and spin stabilized, would the rocket motor even potentially help KEEP the spin stabilization, and even then as you say if the rocket motor burns unevenly or the nozzle gives way, the physics of the motor will suddenly change mid-flight, and that will probably overcome any benefit of the stabilization.

[@Anthromod]

The Dzhanibekov effect perhaps.

[@Backyard.Ballistics]

@@Anthromod probably not exactly that, since the axis of rotation is the one with the lowest moment of inertia (and not the intermediate one), which is stable for rigid bodies. However, non rigid bodies with ways of dissipating energy (like a rocket ejecting gas and burning propellant) tend to transition towards rotating in the direction of highest moment of inertia, which is "head to tail" for a rocket. The behaviour is further complicated by the fact that the center of mass is moving and moments of inertia are changing as the burn proceeds. Even nutation instability has been observed in space. Lesson learned: less spin more aerodynamics

[@richyhau5690]

Maybe rocket arrows would have performed better... At least KZbin would not demonetize it. 😁

The fact that the grain isn't uniform is going to create a lot of instability as well. It _really_ needs to be packed tightly without air inside in order to ensure maximum stability. Also, these tests really shouldn't be done in the city. Imagine if it actually worked rather well, but went over the wall and hit someone... "Safety third" is only okay if *you* are the only ones in danger.

[@Ididathing]

Thankyou for showing me how to make gunpowder

[@jakobrosenqvist4691]

Uh ohh.... This can't end well. Please livestream it.

[@biggusbolungus3118]

Next video Rocket powered BeyBlade?

[@smashface3080]

Like you didn't know before. Btw love your videos mate

[@tasteless_5915]

UH OH

[@kanderssen7629]

Whats next a rocket powered saw blade???

[@MakersMuse]

That vid on taofledermaus is one of my favs I go back to it often. Shame V1 didn't work as intended but please revisit 😍

[@supermaster2012]

We need to settle once and for all which YT crafter/3dprinter can butcher common brands/ products like "prusa slicer" the most. On the one hand, Angus has that thicc melodious accent (prüshsa) but I can't help but to imagine how funny Integza's Portugese attempt would be (prahsa?).

[@therealcrisis8439]

@DanielCook wait, what happened to Danny?

[@RichardCranium321]

RIP Danny... Donate blood, save a life!

[@Sanuske4]

Integza: "This one isn't performing that badly." Rocket bullet: *spins around wildly*

[@Wyi-the-rogue]

Rifle effect :D

[@phgodts]

Integza, I remember your struggle to cast metal using 3D printed molds. I just find a channel showing the best way of doing that, and the results are almost perfect. Robinson Foundry

[@DiverWithTheBends]

Because of the relatively low burn rate of the grain, making the nozzle a higher degree angle and also capping the back of the tube to allow pressure to build up will help significantly.

[@erinfinn2273]

The original Gyrojet guns had a spring-loaded hammer that held the bullet in place for the small amount of time it took to ignite both nozzles.

[@spencereaston8292]

In the tre-flou-ger-mouse🤷 video they showed how even the trigger assembly held the front of the round to allow it to build up pressure inside the sealed chamber. The high pressure is the key.

[@sir_vix]

These seem like exciting and interesting ways to heuristically gain entry to an emergency room. :)

[@rivercityrampage252]

@@spencereaston8292 that's a good way to get a face full of explosion. It's a rocket, it doesn't need a build up of pressure. I would think such a build would detrimental to the propulsion efficiency as well as damaging to any components holding it all together.

[@sage5296]

2:40 This stuff is known as rocket candy (since it's basically a sugar and an oxidizer), you can use it for low powered model rocketry. The reason why it's not generally usable for higher power rocketry is that it's generally very slow burning (compared to real rocket motors), and so a larger mass of it won't burn very fast. I have some friends who made some in their kitchen oven lol (this is pretty dangerous as too much heat can cause the propellant to spontaneously ignite!) Before you start making anything, you should check your local regulation on what amount of energy you can use in a model rocket without a license (where I am it's 80Ns). Do your math and chemistry, calculate out your yields before hand, and don't go overboard! If you do want to make some yourself, I'd recommend a temperature controlled hotplate or gridle, and definitely don't do this indoors! You can find KNO3/Potassium Nitrate online as tree stump killer, and most sugars will work fine (altho some may work better than others). Iron oxide is easy enough to find and technically not needed, tho it helps. Prepare your molds before hand! As stated before, overheating this stuff can cause it to ignite! The shape used in the video with the hole through the middle is the most common design in general for rocket motors, if you use a cardboard/reinforced paper tube you generally will not need to demold it, that can be lit with the rest of the propellant. This should go without saying but make sure you have proper safety equipment, safety goggles, fire extinguisher, clothes that won't catch on fire, etc.

[@vaderdudenator1]

This is awesome. The scale you’re working on is kind of terrifying. Please be careful, you can’t be our modern Tesla-man with no hands.

[@Project-Air]

I knew it was only a matter of time before you made a deadly weapon 😉

[@mrnlce7939]

It's not deadly for the pumpkins.

[@nicograhamdetto7247]

Colab!

[@compositesewage]

Savage

[@spitefirespartangaming]

That's was I was what I was thinking lol

[@CatTechSupport]

Honestly the gyrojet when your talking ballistics and effectiveness of it comparable to the volcanic pistols. The volcanic pistols have a known story to them in which a man bought on for suicide and failed after firing seven shots into his head, living with no projectile even having a chance of penetration of the skull. Quite literally unless you are a mash of rotten flesh or a vegetable it cannot kill you and the same goes for the gyrojet.

[@jakobheinz5009]

Integza: *Literally makes low explosive also Integza: Plastic straws are hard to get

[@isaacsgarage931]

Amazing seeing you hone your low cost techniques and DIY attitude. Can't wait to see more of whats to come!

[@paulbrooks4395]

This is super steampunk. Black powder rocket propelled bullets in a gun made from leftover metal.

[@FedericoLucchi]

I think a "Y" nozzle might be a big help. With the double nozzle, unbalanced or asymmetric combustion inside the rocket results in one nozzle being more powerful than the other. Forcing the gasses through a single throat an then splitting them in multiple nozzles could solve this issue

[@Shreyam_io]

16:54 Rip Danny... he was so entertainng and added life to the channel.... he will be missed

[@anthonyoden4393]

Rip Danny.

[@dashingdave2665]

RIP

[@aaron6787]

The quality of your projects is growing at the same rate as your channel. Gz bro! Thx content

[@gaspowerrules]

Video idea: I would love to see this idea of nozzle continued but to try various design use them on a compressed air and water rocket before attempting them for use with real propellants

[@hiijustin1905]

Idk if I'm allowed to win again. But video idea, use a controlled wireless valve system to make a multi stage rail car, that can speed up over time. Like boosters! Seems this gained a bunch of traction!!! If I do win I'll give away the printer on my twitch :D it'll be a random follower giveaway :)

[@GmanMarvel]

I think the rail car should look like a DeLorean (ala Back to the Future III)

[@hiijustin1905]

@@GmanMarvel that'd be amazing!

[@integza]

Great idea but sorry my man, can't win twice.

[@hiijustin1905]

@@integza perfectly fair :)

[@PlasmaChannel]

Dude that wider pipe almost lead to you impaling your neighbor's dog haha. Sick video bud.

[@Jonas-Jelly]

i like we have a same Video Taste

[@digigeek19]

ATF moment

[@CharlieSolis]

For real though 😂😂😂

[@retromodernart4426]

Integza almost did a thing...

[@evanboser749]

your winning the printer

[@deadpoet4]

I missed this when it first came out. It has been a while, but here are a couple ideas to help the rocket bullets fly straight. 1. You cannot rifle the barrel to get a stabilizing spin, but what about the rocket exhaust? A rifled pinhole, leading to angled exhaust bells for the nozzles? 2. Fins and spin are not he only ways to stabilize a rockets flight path. What do a kite and a bottle rocket have in common? Drag. Some model rockets use a similar method for recovery with a ribbon streamer slowing it on decent. A tiny carbon-fiber ribbon attached to the center of the back of the bullet. Roll it up and place in into one of the nozzle bells to maintain the shape of the bullet when loaded. One fired, the exhaust should unfurl the ribbon, causing drag at the back of the rocket and forcing it to fly strait. Using drag alone, you could have 3 streamers placed equidistant around the back of the bullet rolled and placed into a central nozzle. I think they should be 2/3 times the length of the bullet. Should stabilize nicely.

[@gigaus0]

14:16 Okay now it's just trolling him. 'I need you to spin!' Rocket: 'Okay!' *spins sideways*

[@gidrathanks4713]

I think that Itengza wants to escape into space in a huge spaceship, firing back from aliens with jet bullets

[@JjMn1000]

Lol

[@ludoxz]

So 40k?

[@DeuxisWasTaken]

funnily enough, conventional bullets would be way more effective in space. The jet in jet bullets tries to counteract the slowing factor of air drag. Unless you put enough propellant there to achieve a higher max speed than conventional bullet's muzzle speed, but that's basically an RPG, a small caliber won't cut it.

[@retromodernart4426]

But Nikki "Bugsy" Tesla always said the Aliens were his friends, 👽👽👽

[@richyhau5690]

so if we just need small rpg, why don't build a shrinking machine and shrink a rpg :D That would even be somehow useful 😁

[@GoodRoads]

"Who needs to buy a well engineered X when you can make a much cheaper and crappier version yourself?" Story of my life dude.

[@suspense_comix3237]

You can put 3 holes in your nozzle in a triangle configuration rather than 2 holes. That would fix the stability issues and make the rocket bullet shoot closer to its target.

[@rivercityrampage252]

I'm a fluid mechanics engineer. I think I can see about 3 problems. 1. Your bullets may have an off centre centre of mass due to how you're packing them. 2. They're not gaining enough speed at the end of the barrel. 3. Your narrower barrel is more accurate than the wider. I think that there's a pressure build up in front of the bullet as it travels down the barrel so in order to counter act this, you should cut vents down the length of the barrel. You can see that in the original designs. You can see that when you used a bigger pipe it accelerated more due to I think more gasses being able to vent around the bullet (but reduces accuracy as it can then move around within the pipe). That might solve the second point.

[@OhThatEdit]

Video Idea : Make a sugar rocket, but use a custom nozzle you have designed!

[@theocorkrean6810]

Battlefront 2 boba fett rocket vambrace

[@richyhau5690]

I have an other idea... how about asugar rocket that hovers? Or attach a string at a rocket xD

[@WillZuidema]

He already made a sugar rocket. The custom nozzle, though...

[@Fallen7Pie]

sweet idea

[@ianitusluminous8937]

#teamseas...

[@menogusta9829]

Integza- can engineer and execute his ideas in at a spectacular level- couldn't think of using a paper funnel for the gunpowder 🤣

[@nedisawegoyogya]

I thought the same lol

[@theletsplayer9503]

Idk if anyones mentioned this yet, but im pretty sure the instability is from the fact you only have 2 nozzles. If you had 3, or the designed 4, you'd be able to stabalize it from more points than just opposing sides. Reason for my theory: If their on opposite sides, slight differences in thrust will cause one side to yaw, and that yaw multiplied by roll causes it to tumble out. If you had one more, or 4 like the original, the slight differences could be cancelled out by each other.

[@montgomerygames]

A good ignition compound is just some match heads crushed up and mixed with the striking strip on the side of the matchbox. It can be ignited by striking it and works as a bullet primer.

[@alexander92ck]

Video idea: Use the extra gunpowder to explode a tomato form the inside edit: I did not explain a lot yesterday, i mean for you to somehow put gunpowder inside the tomato and detonate it (don't know if it needs a container for the gunpowder to work since the inside of the tomato is very wet) Tomatoes are disgusting! And since I'm also allergic to Tomatoes you can explode them all!!!

[@integza]

Gongratulations Gokalex! You won a 3D printer! Send me your info (Name, Address, Zip Code, Phone Number) to [e-mail].

[@alexander92ck]

@@integza wooooo sent!

[@bradley3549]

That looks a lot like a center of gravity issue as well. Adding some weight to the front of the rocket may help immensely. If you look at the original Gyrojet, while it is hollow - the front 1/3 of the round was solid brass.

[@allangibson2408]

That’s true of all rockets - mass at the top makes them more stable in flight.

[@garyjimmerson3393]

Yes. The CG (center of gravity) must be ahead of the CP (center of pressure) by typically 1 caliber (1 diameter in length). i.e. Add more mass to the nose tip.

[@allangibson2408]

@@garyjimmerson3393 And then you get spin stabilised projectiles - where the deliberately make them rear heavy so they turn over on impact… (both the British .303 and all the Japanese WW2 ammunition had this feature).

[@tommyboy2260]

That was awesome. A way for the projectile to fly is to rifle the barrel and treat the projectile like a sabot. Possibly rifle the sabot to match the rifling of the barrel... That was cool and lots of potential power in projectile.

[@brenkrasmer]

If you re visit this, a couple of things that may help in your design: First, having the nozzle exhaust be connected to a single and clear inlet. In the current design, if the burn begins on one side and not the other, more gas will be escaping on that side, throwing off the projectile. More exhausts. Having seen a breakdown of the Gyrojet, it had about four ports. No process is perfect, but having 4 smaller points of variance helps to balance 2 large points of potential unevenness. another hypothesis for improvement (read: completely unfounded guess) would be to have small, very steep "rifling" exhausts, and a central main thrust exhaust. Mathematically, it may be the same as shallower rifle and thrust ports, but it may help to smooth out any variance in manufacturing. Lastly, weight balancing. If I'm correct, most of the weight is in the back. And so a millimeter of deflection in the back is several degrees of deflection around the center of balance. If the center of balance is far forward, the same back deflection will become a lesser overall deflection in trajectory.

[@KharmaMedic]

Your videos are incredible! I can't imagine how long this all takes

[@scorcher46]

First

[@nagasaipurvaz4251]

What ?

[@integza]

Thank you !

[@xmysef4920]

Integza: *Shows how to literally make gunpowder at home*

[@ksp-beginner9458]

Yeah im going to save the recept for gunpowder now

[@ThePapaja1996]

and rocketfuel

[@letsflipp]

well, not like there aren't dozens of tutorials on youtube on making black powder

[@bigcountry908]

Shhhs don't tell the youtube mods

[@letsflipp]

@@commandingsteel well, integza isn't in the US as far as i know, so that's all pretty irrelevant? youtube just is quick to hand out penalties for instructions on anything dangerous i think.

[@CallumPRobertson]

For moving powder around, try just taking a little bit of paper and pinch it right at the centre of one of the edges, to add a "fifth" corner to it, which acts as a little funnel :) We use it all the time when measuring things in chemistry :D

[@fatmaninparadise2003]

Best quote in the entire video: "I need those rockets."

[@ncot_tech]

I like how you're literally making explosives, and the hard part was finding plastic straws 😅

[@leechowning2712]

Welcome to the 3d printed age. This is why they fear "ghost guns".

[@BetweenTheBorders]

He's making rocket candy, a propellant. It doesn't detonate, it burns. Explosives don't work as gunpowder or rocket fuel. Edit: Unless you meant the black powder, which is fair.

[@rc-fannl7364]

Everyone knows plastic strays are far more dangerous than gunpowder, right? ;-)

[@SwainixFPV]

@@BetweenTheBorders gun powder is still a low explosive, it burns and doesn't dotenate so ""it's fine"" I guess lol

[@Shad0wBoxxer]

That straw hat in the beginning made me cry. Rest in peace Danny from Taofledermaus. You were a hell of a shot and im glad you got to shoot the gyrojet. You were a uncle to many. Thank you integza for your video

[@IFly664]

love your videos keep up the good work

[@fafane65]

The first bullet leave a beautiful spinning trace in the acrilyc pipe. Noice!

[@alexbirdwell7299]

It would be awesome to see two aero spike nozzles set up for the gyroscopic “projectile” . Why? Because i think they look cool.

[@nic.h]

Or just 1 with fins integrated into the nozzle

[@DeuxisWasTaken]

"This one didn't perform that badly..." [cuts to rocket horribly tumbling from the moment it exits the barrel]

[@debjennings4686]

You could use a spiral-grooved barrel if you had a sudden rush of gas or an explosive charge to get the bullet up to speed, then the rocket propellant will keep accelerating it once the projectile has left the barrel

[@davidmcintosh5441]

Aerospike nozzle on the gyrojet but with two slight spiral vanes down the expansion surface to create torque. It will be easier to print and more efficient than the two nozzle approach. You can truncate it to 75% length and have a hole in the center for your fuse which will be glued in and sealed with sliding connectors on the electrical wires to allow separation. This will stop you having to put the fuse up a nozzle and have it blocked.

[@DrewTeter]

"Honey! The crazy neighbor is firing explosives at the side of our house again...." But honestly, your projects are all insanely entertaining.

[@starter0951]

When all your neighbors had to worry about was a ball. 2021: 🚀

[@domstatt1423]

I love the philosophy: if the rocket misses its target, you have to add more pumpkin :)

[@sublimationman]

BTW you can make a much simpler igniter by putting some wood glue on the center of some of the nichrome wire and roll it in gun powder, you can do this a few times to build it up but it really does not take much.

[@bigolmemoryhole6944]

Like rocket assisted artillery I could see rocket assisted bullets maybe adding to sniper rounds either to allow ultra long range or larger calibers with manageable recoil in an anti-material rifle however the bullet machining tolerances, especially their venturi nozzles would have to be exceptionally tight.

[@babaksanaee1460]

Couldn't help but imagine the glass blowing up while he was dancing after just saying no sparks

[@EngineerBrunS]

Cool project, and good humor!

[@A.R.77]

16:15 ~ That was way more cool than had it just exploded. Love you work.

[@Tee0505]

you can use a plastic bottle half with water and pressurised air so the air pushes the water out creating thrust. (It should be easy to add an aerospike nozzle)

[@BernardSandler]

Honestly, at this point I'd love to just see you form nozzles out of clay on a wheel (oldstyle) and glaze them. I think you might get better results with way less complication. No porosity, far easier to prototype and I think you'd be surprised by the repeatability. Also, I think traditional glazes would hold up under the temperatures you are looking for.

[@wreynolds]

I’d love to see something similar to lost wax. Print the part, bake it in plaster, then go ceramic or metal.

[@jacopo.gabrielli]

VIDEO IDEA: Since you have a lot of empty Co2 cartridges why don't you use as a tank for solid rocket fuel (for example the sugar one). With cartridges you can get a nozzle simply by going to countersink the hole. The divergent part will be missing, you could perhaps weld, on the outlet of the cartridge, a bolt or any suitable piece of metal and then countersink for make the divergent part of the nozzle.

[@detritus10001]

That's some of rhe best homemade black powder I've ever seen!

[@deadsounds8708]

my guys got that blippi look nailed

[@nosenseofhumor1]

Try 1.) closing the back of the gun, that’ll give you a ton of force going forward 2.) create a rifling guide rail down the pipe to control the rate of spin and ensure it has a nice head start spinning before leaving the barrel. Still it will be wild and uncontrollable but maybe less so

[@justinhall835]

The gyrojet is one of my favorite forgotten weapons ever produced! Especially the long barrel version. Thanks for making this! Also, a steeper angle on your nozzles (about 45*) or thrust deflecting vanes on the backend may help solve your stability issues while maintaining the same bore size.

[@pandoranbias1622]

Bro those rounds are absolutely *massive* for even a rifle.

[@Sniperboy5551]

I love the fact that you used the TAOFLEDERMAUS video in the beginning, such an awesome channel!

[@nickcook2775]

"They were not performing as well as [we] expected" Just like the real thing...

[@RRRob.]

I’d still like to see you try to 3D print a high-pressure water compressor and nozzle to build a water jet cutter for tomatoes.

[@jasonlapp4559]

This guy is awesome! I have been watching his video's and now I'm late to work. very late LOL!!! GREAT WORK!!!

[@ryanlebeck259]

The original gyrojet bullets had rifling on the outside to cut wind sheer down, while your CO2 canisters did not. Try using your 3D printer to mold ceramic cases for the bullets with the corkscrew rifling and see how that affects the results. Also, when making your candy rocket motors use wax paper or parchment paper in your molds to reduce sticking, and a medicine funnel works like a treat for pouring powders into small capsules.

[@JoelCreates]

Fascinating, but don't you realize that modifying co2 cartridges is dangerous?

[@integza]

I learned from the best 😂

[@hermanrobak1285]

Cooking his own explosives deflected the "don't do this at home" needle quite a bit more for me...

[@jimjjewett]

@@hermanrobak1285 And sealing them in with hot glue. I almost expected him to solder the plastic explosive container closed.

[@polydullmemes3497]

@@jimjjewett the hot glue isn't that dangerous though, there are no sparks to cause the gunpowder to ignite

[@southern_merican]

Driving to work is dangerous too

[@aimfar7946]

Whooooooooooooooooooooo, clicked fast than integzas developments in rockets

[@plutonianfairy]

I think it might be more stable ang faster if you close the back (so that it can build up pressure)

[@mattiamagnano9758]

From the slowmo you can see that the exhaust is not coming out symmetrically and is instead going mostly into one direction, you should try a single hole on the inside that then leads into two exhausts

[@LabCoatz_Science]

Great video, as always! Maybe you could try adding nozzles on the side specifically to cause the high-speed gyroscopic rotation (kinda like those Speed Ball fireworks NightHawkInLight did a video on). If you can get those bullets spinning faster, they might travel straighter!

[@Nyquil98]

video idea: since you're having trouble with the nozzles melting, have you looked at lost PLA casting? basically using PLA to print anything you want, putting it in casting material, melting out the PLA then casting the area left be the PLA in whatever metal you want. Probably harder than it looks, but probably more your style since machining isn't really part of your content.

[@chenkunnie]

I think Integza mentioned before that casting is too much trouble and the easy aluminium casts can't stand the heat, but still a good suggestion, it's probably the best way to meet the goals with 3d printing involved

[@Kekatronic]

you gotta add a back to the barrel so pressure can build up behind the bullet giving it some kick coming out the barrel, at that point you'd want a tight fitting barrel.

[@pure2stroke888]

Integza I love your videos

[@sirmammengaming7405]

"who needs to buy a well engineered (object) when you can make a much cheaper and crappier version yourself" perfect integza moment

[@SomeoneTookAK]

"why buy when you can D.I.Y?"

[@sirmammengaming7405]

@@SomeoneTookAK ah yes, the D.I.why

[@no-hr3cv]

Video idea! What siege weapon is the best at launching tomatoes? I want to see a tomato get launched 100mph into a wall by a cannon!

[@kashifrit]

i think the best utilization of this is in sniping. flatter and longer trajectory is possible

[@fluppet2350]

You could try to angle the rocket so that it propels it in a circle instead of straight on. That might help with the tumbling. Another thing that will reduce tumbling is having 3 instead of 2 outputs

[@feku_pl]

From my experience I would recommend 3 holes, 2 for rotation and one in the middle for forward thrust and experimenting with size and tilt of the nozzles.

[@DraconicDuelist]

I was thinking 4 holes. 3 to balance the spin, with 1 centered for speed (which is key).

[@feku_pl]

@@DraconicDuelist There is no need to balance, gyroscopic force is more powerful than you might expect. Even 1 hole might work

[@sirstroam]

Drop the tomato on a chair with two needles poking through. When the needles enter the tomato, the tomato generates a small voltage. When the small voltage is detected, it ignites a thruster that propels the chair up and smashes the tomato against something. Use slow motion to really capture how the tomato squishes and bursts.

[@stianberg5645]

I have been tinkering with something similar, and have some ideas! I think a stretched rain-drop shaped projectile could work. Make it narrow for less drag, front heavy and with a tail for stabilisation. Place the nozzles where the tail piece begin. Or don't use the nozzles to make it spin at all. It causes instability if the fuel burns unevenly between the nozzles. Perhaps a pressure chamber before the nozzles could be another fix, but that could make the projectile even chubbier when it needs to be more aerodynamic. For the barrell: launch it from a barrell with holes to reduce air resistance and smooth out turbulence. Alternatively, seal off one end to make better use of built up pressure. For ignition: you could run the wire through the casing, and use that for one of the poles, while the other is, for example the tail. I don't think gun powder burns evenly enough, as you need an instant ignition through the whole of the rocket. That way you can ignite it so that it burns from the centre, through the whole casing. it should improve accelleration, which in turns gives you accuracy and short-distance speed. The central "tube" (or mandrel) used for the mould could also be star-shaped to expose as much area for ignition as possible. This is done in solid fuel rockets.

[@twicebittenthasme5545]

The stability issues aside, this was very cool! Have you tried anything like "snap-out fins" similar to those found on types of aerial and submersible explosives? I have a suggestion for a future video along this theme... You had a rocket-powered pumpkin but all it did was sit there. How about launching it into the atmosphere and as an added bonus, release the rocket bullets at a certain point. Like certain fireworks do to achieve multiple displays. The bullets could be mounted on the outside of the pumpkin also with a fuse style igniter to propel themselves higher. Just a thought.

[@simonjensen596]

3D print a threaded extension/choke for your barrels. Also, it looked like the bullets weren't going very fast out of the barrel, but then accelerated a lot when they reached the pumpkins. Maybe try something that will give them a higher muzzle velocity - I think that would add a lot of stability.

[@cacaokingdom3122]

That was actually by design even with the originals. They had a relatively low muzzle velocity and accelerated once leaving the barrel. The original barrels were more holes than tubes so they had ZERO pressure inside the barrel. You could literally see the bullet in the chamber when it fired and could see through the barrel down the entire length of the barrel.

[@Dinitroflurbenzol]

just add a small kickstarter charge and boom: you got a bolter

[@kulderij]

Better way to make the starters without the straw: cut up some ping-pong balls (highly flamable), and dissolve them in some acetone. Then mix the gunpowder in with the mixture till you have a paste. Dip the wires into the solution and let dry. You can dip multiple times to get thicker layer. Works perfectly and no plastic straw needed.

[@Mis73rRand0m]

Gasoline and styrofoam works as well. Add some limonene (goo-gone is a good source) and you'll have napalm that spits balls of sticky plastic fire.

[@nic.h]

Can also use steel wool instead of the wire he was using as it's easily available and works ok as well

[@CryoseGaming]

I am now on a list for watching this

[@fladder1]

"who wants to buy a well engineered gun when you can make a much cheaper and crappier one" makes for a nice motto! I think I'll steal this from you

[@Mr_Giraffe]

How about using the CO2 casing as the mold? A perfect fit everytime and no need to move it.

[@Barskor1]

Cool, I should have scrolled down father before posting the same idea I added some more suggestions have a look :)

[@stianberg5645]

yeah, but first solder the ignition wire to the front, and run it through the mandrel, which should be star shaped. use the casing for one pole and the nozzle as the other pole. that way he can ignite way more fuel instantly and improve accelleration.

[@battlesheep2552]

I think the problem is it needs to be smaller than the inside of the casing since it's meant to burn from the inside and the outside. Otherwise it wouldn't burn quick enough.

[@Barskor1]

@@battlesheep2552 Gun cotton but rather than made with cotton balls grind the cotton to powder before nitrating then mix into the rocket candy should give a high burn rate.

[@timbercook6833]

Try metal 3d printing by placing pla models in sand/compacting material for molten metal once you get the shape take pla model out and then pour molten metal In it you can cut it in two halves our use dissolvable filament.

[@operator8014]

When I was a kid, we made ignitors kinda like these with duct tape. Just take a strip 2in or so long, and fold it in half, making a small pouch for your charge. Put the resistor in the top and pinch it closed. Self-sealing!

[@ArtoPekkanen]

The best design would be that the self-propelled rocket would be encased in a shell with a propellant. The piston would propel the rocket out of the barrel conventionally, and at mid point of the barrel would be electric contacts which ignite the electric primer in the rocket itself. This way you get initial acceleration with the propellant in the shell, and then added acceleration with the rocket. Might be really hard to make it work but just a thought ...

[@imranhossenrahat3737]

Why don't you make a rocket power plane.

[@bavankarthik7634]

Cause he is integza, not tom stanton LoL

[@Anonymouzor]

i would love to see a video where you experiment with the various physical properties of the ceramic material after doping it with various things like casting epoxy or even just frozen water!

[@nicklego2379]

this is the best rocket that he has made yet, it actually works

[@GeoThaDude]

Could you also use some rifling inside of the barrel/tube to get the gyro started? This could help with them tumbling when they exit the tube

[@rutuparn6188]

Next project you can make a metal part with 3d printing by making the model with pla and the cut it bilatetaly in two pieces and then use the moulding method with filling sand/silica around it and compacting it and then take out the two pieces and pour molten metal into it once done join both of the parts (You can also use water soluble filament for complex models)

[@harshp5454]

video idea : use the same gyro bullet from double barrel and smash tomatoes and pumpkins ,Happy Halloween

[@tf2weeb663]

I have a suggestion - turn the bullet into a rocket propelled APFSDS round. This eliminates the need for a spin but you do need to turn it into a metal arrow. The fins on the back will reduce the spin to stabilize the arrow-shaped round and keep it straight. This also means you need a bigger barrel to fit your homemade shell and a way to create a discarting sabot.

[@DerRoflator]

In Nerf Modding people normally use a Scar Barrel to give the Dart a spin. Some say that the Dart is also more stable because the Air behind the Dart isn't pushing the Dart in some Side Directory. While the Dart is in the Scar Barrel the Air dann escape to the sides. Maybe something like that would help stabilize it.

[@jamesm783]

Keep at it integza! once you solve the nozzle problem, I'd love to see you take another shot at this

[@DaimyoD0]

You should try milling nozzles out of graphite! You could do it by hand, but a CNC lathe might make life a bit easier. *Edit:* For anyone interested in recreating Integza's rocket candy from this video, I implore you to do so on a hot plate outdoors, with a double-boiler/oil bath to evenly heat the pan and avoid hot spots, and with PPE-at least eye protection. I'm not your dad, and I don't mean to be the safety police here, but I personally spent New Years Day in a burn ward when I was 15 making this exact recipe on a stove top. Do yourself a favor and learn from my mistakes! *Edit 2:* I also think it would be cool to 3D print parts, give them a surface coating with a conductive paint, and then electroplate them. Personally I've only ever tried this is copper, and it was for art, nothing structural, so I don't know if there are metals with high melting points that lend themselves well to electroplating. And having a thick enough layer of metal to resist melting and oxidation might conflict with the requirement of tight tolerances on the parts. But I thought it might be a cool idea nonetheless. I have also always wanted to see a rocket nozzle with active cooling in a model-scale rocket, maybe with channels through which liquid oxygen can flow. I suppose this would also increase the risk of the nozzle blowing up lol

[@christianstorms3950]

He mentioned graphite himself, too. I wonder (and have no idea), how graphite works with excessive heat. But it seems to hold up well(?)

[@martingarnett9381]

Graphite can handle extremely high temperatures, but will burn if exposed to a flame.

[@DaimyoD0]

@@martingarnett9381 Now that you mention it, I am seeing some reports of graphite burning at temperatures as low as 400°C, which is much lower than I had initially suspected. I wonder why it is often selected for rocket nozzles?

[@firstnamelastname.7749]

How did it catch on fire when you where cooking it? Was it over a open flame?

[@waffleface4368]

@@DaimyoD0 I suppose its because graphite is a good heat conductor, so it would spread heat evenly across the nozzle and redirect it to the casing as well Also the burn rate of graphite would probably be negligible compared to how little time the fuel burns for

[@jacklougheed4561]

Integza: hey, can I get a plastic straw Clerk: no, those aren’t allowed to be sold here I: what if it is for a homemade bullet, not drinking from C: I: C: I: I’ll see if anyone else carries them

[@akramkimou2325]

Hey joel, it seems that u forgot about something called the "Yaw" axis when making those bullets wich greatly impacts the performance of the "rocket bullets" because when they turn around they reverse thrust and tvat impacts the speed and the precision of the bullets