Propulsion Types - Landing Model Rockets Ep. 2

[@BPSspace]

I thought the joke was clear enough, but in case there's any doubt... I am not HUNDREDS OF MILLIONS OF DOLLARS in debt 🤦

[@Enthropical_Thunder]

For the controllable booster problem, couldn't you put a very simple nozzle shaped piece of heat resistant metal infront if the the motor. To control the net thrust , you would have to put a kind of bleedvalve on the side, to bleed of chamber pressure and therefor reducing thrust. With this methode you also have to ignit the booster very early because you basically can just reduce the thrust (assuming that the bleed of valve can't close because of the high temoerature gas). The principle would be the same as your multiple mini rocket motor idea just with the advantage of possibly less weight and a bit more controllability (since the time delay for solid rocket engines is not that consitant, wich could probably end up in unwanted thrust difference an instability) and the disadvantage of being a bit more expensive. Well it was just a quick thought ;D.

[@andrewmorris483]

I was thinking monopropellant. High-Test Peroxide fed onto a catalyst shaped kinda like a cork that forces it around an engine bell.

[@Enthropical_Thunder]

@@andrewmorris483 I was thinking about that too but wouldn't the catalyst be expensive? Than you also have the Oxygen in the water steam (when using hydrogen peroxid) that is unused (a more effective approach would be be to use a second liquid as fuel, for example methanol. Or go hypergolic and use a mix of methanol and hydrazine as a second liquid). The cold type Walter engine is in between solid rocket motors and liquid fuel motors in terms of complexity but i doubt it to be any near their cost and time effectiveness.

[@danielfeitoza8489]

And what about you do a nozzle that can change the diameter of the exit, so if you reduce the diameter of it you will get more thrust because the increase of pressure inside, and if you enlarge the diameter of the nozzle you reduce the pressure also reducing the thrust . And the solid rocket engine would be one that burns a little slower to be better adjustable. exemple: giphy.com/gifs/jet-engine-6WfCXaS1VIkFO

[@Enthropical_Thunder]

That's a good idea even thought the pressure inside is not what increases thrust but rather the increased velocity at the smallest nozzle radius (rule of thumb: the smaller the radius the higher the velocity for a given volume flow. Increased velocity by same volume flow should result in higher thrust).That said, if you have very hot gases like in a rocket motor, you will get a lot of heat flow. Now imagine even more heat flow because of increased velocity, professionals have problems, cooling static nozzles with fuel and you want an amateur to built a dynamic nozzle with cooling for every moving hot part of the nozzle. That's not gonna work, at least not with his limited budged ;D. Don't get me wrong, it is totally cool and works for relatively low heat exhaust gases like turbo jet engine with or without afterburner but rockets require a little more heat resistance.

[@jerry3790]

If you’re over half a million dollars in debt, spending $2000 on a liquid engine won’t make much of a difference.

[@nabzim]

If he's that far in debt, maybe he should slow down a little with the spending... and, if he wants to be creating a product geared for the hobby industry, he will stick with standard solid motors. and it looks like he's doing that. Although........ if he were to develop a compact and light-enough liquid rocket engine, he just needs to find a way to mass manufacture them easily, and cheaply, and viola, he has created a new market. Then it's not long before there's chinese copies of all of his original ideas... Let's hope he's getting patents for all this stuff (but China don't care 'bout no patents do they...)

[@curiosmars2100]

r/ wooooosh

[@km5405]

woosh lol.... but maybe 3d print the engine....you could probably do it very very economically that way. probably the preferred way for something that small as well

[@vertex3243]

@@nabzim it was a joke

[@nabzim]

@@vertex3243 I think I may have missed it because I didn't watch the whole video... my bad! But I'd still stand behind the rest of my comment.

[@sgibbons77]

The bank account joke alone is worth the thumbs up on this video.

[@jls5020]

I already build a hybrid engine that small and it worked really good. And it costs here in Germany about 30€ +servo, valve, housing. The housing is rusable. It just needs some cleaning before refueling. I used liquid Oxygen as the oxidiser and PVC as fuel. The housing is aluminum and the nozzle steel. Its 10cm tall and 2cm wide. And it weigts with servo and valve 200g. I did not mesure the thrust but it had alot of boost. Greetings from Germany👋

[@vurtnesaerdna]

JL S Hi ， can you upload a video of the engine?

[@MrMichalMalek]

I also wish to see it in action if possible

[@frankhammer6795]

Me too! I would love to see this in action! Please post video soon!

[@Jupiter__001_]

LOx is hard to make, how did you get it?

[@jls5020]

@@Jupiter__001_ I just used the Oxygen from my oxy acetylene welding equipment

[@jadons.1342]

The fact that you taught yourself and know just as much as the guy that went to MIT is amazing

[@SamTanXYZ]

"rocket-rich combustion" lmao

[@kellynyanbinary]

Samuel Tan I prefer engine-rich exhausts though.

[@rreiter]

me, rapid unscheduled dissassembly

[@haph2087]

“Rocket-Rich”? Just throw more rockets into the combustion chamber than descent vehicles. Simple.

[@adamrezabek9469]

SN8 made it a thing

[@rcpi9336]

You're like a mix of Elon Musk and Veritasium and I love it

[@zen6767]

holy shit he does sound like derek

[@Fred_the_1996]

And backyard scientist

[@Mark-sr3jw]

He is a solution of more than 2 solutants😝😝

[@vertex3243]

he is his own person

[@ryanchowdhary965]

@@Mark-sr3jw quantum irregularity

[@sleepingpowder1595]

You look like Elon Musk but with more sleep

[@CLYZRbby]

I was just thinking the same, maybe hes related to Elon :D

[@clemensoldoerp7087]

Yes!

[@digitalvectordrawing318]

Savage

[@ivofuentes9760]

its baby elon HAHAHAHA

[@sleepingpowder1595]

@@coopergarrison6589 no one asked

[@omermagen824]

I googled "Bad things that happened with nitrous" and now im watching a Mustang drifting into people

[@matthewcragg3607]

You can Google just about anything and end up watching Mustangs flying into crowds.

[@sea_kerman]

You can "Throttle" by having two motors and vary their outward angle to change the magnitude of the net thrust vector.

[@seaturtle5757]

I want you on my team!

[@NoahPurdy]

But... What about Nuclear pulse propulsion??? ;P

[@dazzifoxking1560]

the only time that nuclear blasts were considered for propulsion that I know of was Project Orion.

[@Aaron.A22]

Noah Purdy No ...see Viktor Schauberger work .

[@JAMOABGLP]

their thrust is too low for lifting a rocket of the ground, but great for long term accerleration if traveling interplanetary or interstellar. :)

[@Jupiter__001_]

@@JAMOABGLP Nuclear pulse propulsion literally means dropping a nuclear bomb out the rear end of the craft and detonating it, sending the ship flying through the air. It has plenty of thrust. You might be thinking of nuclear thermal rockets, which have a fission power cell with uranium rods that is used to heat the hydrogen propellant. This doubles as its coolant, and so a major source of weight is removed, but nevertheless it has indeed too low of a thrust-to-weight ratio to be used on Earth.

[@JAMOABGLP]

@@Jupiter__001_ oh yes, you are right, I thought about that after I wrote the comment, (yes heard about the Idea of nuclear propulsion before) but thought it would be alright, now I understand the smiley ;P

[@AirCommandRockets]

Very interesting video. What about 2 solid motors next to each other that can swing out using servos so that they point towards each at their tops. The vertical component of the thrust vector can be controlled, and the horizontal component of the thrust vector is cancelled out. This will also allow you to compensate for the thrust curve of the motor as it changes over time. You already have most of the hardware to move the motors. :)

[@MadOverlord]

Air Command Rockets yes, this is what immediately occurred to me. At the cost of a single servo you could get very fine control of the z thrust vector, and the central vectored motor could compensate for residual differences between the small motors.

[@leveckfamily8841]

Impossible to light those motors simultaneously though and even if you did they are going to burn out at different times. All this happens VERY close to the ground and with the smaller motors, a couple seconds apart. That's why the space shuttle always separated from the SRB's BEFORE they ran out of fuel.

[@oogityboogity6644]

Interesting idea definitely need great timing

[@Krispykleenex]

I watched the whole video. I hate how I didn’t find this channel sooner. You and your passion it amazing.

[@jacobknollinger4943]

Why doesnt this guy have more subs? Keep up the good work! I always wanted to see this happen at a smaller scale!

[@WisdomVendor1]

I've never heard of the term Potential Failure Density... I've always just said the more complex it is, the more likely it will fuck up. :)

[@MoneyManden]

I was watching netflix, but then I saw that you had uploaded.

[@dopedreamz]

Best statement in this video ' rapid unscheduled disassembly '

[@camerononan9356]

absolutely love it man. super excited for the future of this series and can't wait for your channel to blow up. keep up the good work

[@mikebruns1300]

Did a little bit of modeling back in my early teenage days. I have been watching your Facon Heavy videos and thought about this video and others you have tried. I think an easier way to solve this problem is not more motors but by using the principle of a camera shutter. Using a shutter below the motor to open and close it to get the thrust you need. Anyway, keep up the videos. Not sure I would ever get back into rockets but right now I am living the dream through your videos.

[@-coolerlegothings-9784]

Sorry if this sounds disrespectful, and I know this is a year old, but a camera shutter design would easily trap exhaust gas into the chamber, and the body tube is just made out of higher quality cardboard, not a good idea

[@MansellRa]

Enjoyed Charlie & Jonny adding their insight. I will definitely be checking out the links to Jonny's work.

[@nielsquackels6872]

It says your comment was placed 5 days ago but the video is only uploaded one hour ago. Are you a patreon?

[@BPSspace]

This video was released a week ago but was only made public today. Patrons get early access to videos as one of the rewards!

[@MansellRa]

@@nielsquackels6872 Yes, I am a Patreon! I've enjoyed the perks of being a Patreon and encourage others to be one too!

[@Arnogorter]

I think underspec'ing the main engine is definitely a good idea. This allow you to split the functions: -Main motor provides lateral control -Ring of small motors can provide throttling A straightforward way of reducing thrust would be to put the small motors on a simple hinge, allowing them to vector +-90 deg outboard. Either actuate the hinges individually or have a ring that connects all the hinging motors, allowing you to change their angle with only on servo.

[@uweeby69]

Don't worry about video length. I loved every minute of this and left wanting another hour.

[@astrovens]

Can't wait to see you actually land this thing! I'm very hyped for this.

[@transistor754]

my friend you need to read what the Germans were doing with pressurised liquid before the war... the Racketenflugplatz. They made multiple succesful launches at a small scale. Werner came on the scene after they had done a lot of succesful launches. They used what we'd call medium technology, more easily accessable nowadays. Good on ya!

[@awood12345]

IMO an EDF fan is clearly the best solution as it is cheap, powerful and easy to vector and throttle. But that is far to sensible so I salute you for making this a real rocket.

[@DangerousStuffEJP]

I learned more from this channel then I have from school in 8 years

[@alejandrocabrera7626]

I appreciate the production quality of this.

[@RubenLensvelt]

Four small motors. That's a such a charming idea. I love it.

[@ThenotsoboringMan]

You're doing great work! I hope you know that and keep going!

[@LordJon25]

I gave you a like even before watching the video becuase I knew that it will be awesome :D! Keep up the good work!

[@maazahmed9010]

Buidling a rocket is really no joke, thanks man for making these videos for us 😊

[@chairpara]

To throttle solid fuel engines you could try and divert the thrust to the side by for example closing the channel to the bottom of the rocket and opening a new one on the sides of the rocket so that the thrust that goes down can be controlled while the engine burns normal.

[@CuervoRC]

I was watching the video and came up with a way to control the thrust power of solid rockets. Simply by reducing the force exerted downwards by the motors by tilting them to one side so that part of the impulse is lateral. That would make the rocket go sideways but it is corrected by putting another motor that moves symmetrically on the other side. If the rocket with one engine could land, having two would have to go to 45º and you will have an acceleration control of up to 200%. Then the two rocket motors would go together in a gimbal to control the rocket and to correct the power differences between one motor and the other. I hope it helps you, this system is the one I used a long time ago in the physics simulation game algodoo.

[@CuervoRC]

You could also do it with an EDF, is propelled with air so it is not a rocket but for modeling it is the cheapest and you have total control of the throttle.

[@vurtnesaerdna]

what does EDF stands for?

[@CuervoRC]

electric ducted fan, These are the motors used in small RC jet airplanes

[@nickmoline1377]

The show stopper there is angular momentum. Though you could use some aero surfaces below to counteract it. another idea is a small CO2 cartidge with a small solenoid vavle. It is just relativly heavy and big.

[@FelonyVideos]

That does seem like a decent way to get throttle out of a solid rocket.

[@monishnasa9880]

Wtf .l..this is tooo good wow !! Plz keep posting !”!!! I love urrr content

[@MCFishNuggets]

Bank of online banking

[@BPSspace]

Bank of Bank is my favorite bank.

[@jimmysavile69]

@@BPSspace I prefer bank of bank of bank

[@SGAzozy-AzozyGamingYouTube]

@@BPSspace bank of bank banking bank

[@evannibbe9375]

@@BPSspace I too have an account with the Federal Reserve.

[@Tony770jr]

If you want a light weight and easy to throttle liquid engine, try using the hydrogen peroxide gas jet used in those flying jet packs. They use 90% or so Hydrogen Peroxide and by using a catalyst, like silver, it gets converted to a gas very quickly. Forget trying to use anything flammable for the decent engine - which is way too problematic!

[@michaelwoodhams7866]

90% peroxide can also be used to make bombs, so you might have troubles finding someone who will sell it to you.

[@Diversensato]

Isn’t that just normal rocket RCS?

[@williamforbes6919]

@@michaelwoodhams7866 And what, perchlorate oxidisers or solid fuel component cannot be? Peroxide will probably have some strings attached, but can't imagine it will be anything compared to a lot of fuels the hobby rocket community uses.

[@km5405]

also HTP is a pretty aggressive chemical. requires special handling, because it tends to light things like clothing on fire.

[@Nightmare-kg7xd]

It was interesting hearing about Joe's outboard motor idea

[@christopherpardell4418]

I am curious... when a jet lands, it deploys thrust reversers to brake its forward momentum. It seems to me that lateral symmetric deflection of the solid rocket thrust would have a net zero effect on acceleration or deceleration, while actively reducing the thrust in the decelerating vector. Is there no way to effectively and dynamically divert some variable proportion of the thrust to effectively give the result of throttled thrust? Conversely... could you employ some form of dynamically active drag that would affect net thrust? i.e. higher drag equals More thrust, lower drag equals nominal thrust?

[@wunderfuel]

Yes. something like variable clamshells to redirect exhaust in varying amounts + gimbaled engine mount.

[@mduoba]

The stream of gasses are pointed forward, thats the thrust

[@christopherpardell4418]

mduoba yes... but of you deflect the exhaust gasses laterally and symmetrically, it should cut the thrust vector that is slowing the descent. You ought to be able to reduce EFFECTIVE engine thrust thru diverting the thrust...an this achieve a result similar to engine throttling.

[@DouglasEKnappMSAOM]

@@christopherpardell4418 But as many have said no two engines are EXACTLY the same. Thus you would end up with sideways thrust that was not symmetrical and also they will not start and stop at EXACTLY the same time, again resulting in lateral thrust and a crash.

[@christopherpardell4418]

Douglas E Knapp - that’s true... however, it’s a dynamic system no different than he is already using to vector thrust- the flight computer can, in real time, assess the effect of lateral deflection of thrust, and adjust the deflectors accordingly. Deflectors would not be in an on/off state- but would gradually engage with a gradient of deflection. Moreover, he’s only using one engine for landing... once that engine is lit- it’s thrust is its thrust- never the same and somewhat variable- because of which he will never be able to land the rocket unless he CAN modulate vertical thrust to some knowable amount. He would also still have thrust vectoring, but the deflectors could be designed to either gimbal with the motor, for a stable effect on engine thrust- or such that the motor gymbaling would engage deflectors more or less which would add nuance to the effect of vectored thrust. That is, if tipping the motor in Y to correct pitch, it might play the exhaust stream more over the Y deflector- which directs thrust laterally- this would make the moment applied to the y axis greater for a stronger effect on attitude, while cutting engine thrust directed downward. As the vehicle approaches ground, being able to use vertical thrust differentially to help orient the vehicle is not only throttling vertical thrust- but using the thrust you bleed off as a lateral thruster... depending on the design of the deflectors, it might also confer roll authority.

[@user-fj4mb5jh8o]

If you wanted perfect control you could tilt the 4 outboard motors out to reduce thrust(some of the thrust would be going out instead of down)

[@Squeezmo]

Thrusters: straw diameter rocket motors with internal ignitors and conductors 3D printed into the fuel grain (need quicker ignitors to start a burn and insulation wafers to stop the motor burn after each pulse) and burn barriers. Multiple rocket motors along the straw-tube length. Each one ejects itself after its burn. Motor can have curved nozzles so the motor can be installed axially while the thrust gets vectored radially. This tactic might even be used for the main motor by having tubes gathered together for the main motor (Thrust and duration controlled by parallel and sequential firing of the tube sections. (No gimbals)

[@lukezhang3017]

Congrats on your first stick

[@Enthropical_Thunder]

You Sir just won a new subscriber :D.

[@dazzifoxking1560]

yey, a new video! I always enjoy watching them!

[@tsilfidis1996]

good luck on making it!

[@ethanbreen5500]

Can you teach us how to code? I would love to make rockets with servos and stuff but I don't know how to code.

[@BPSspace]

Sure! I'll build it into the Landing Model Rockets series! It might end up being a few separate videos, and of course they'll be focused on writing flight software, but we'll certainly get into that. In the meantime there are plenty of great tutorials about the Arduino or Raspberry Pi platforms on KZbin.

[@ethanbreen5500]

BPS.space alright! Thank you so much!

[@Cat-ct9hn]

Ethan Breen I can personally recommend the book „Python Crash Course“ by Eric Matthes. I love how clearly it is written and you can really understand it well. Apart from that, it‘s really fun to run your programs on a Raspberry Pi. That is a small, low-cost computer that not only runs a whole Linux operating system, but is also able to directly communicate with motors and sensors. The Raspberry Pi Foundation provides a lot of fun tutorials.

[@ethanbreen5500]

007Cat24 thank you so much for the advice I will definitely look into that!

[@MonteFleming]

Cool--this video answered my previous question. My experience with Estes engines is that their impulse isn't consistent enough from engine to engine to do what you need them to do.

[@waltzofthestars2078]

"rapidly disassembles itself in a ball of flame"😂

[@evannibbe9375]

The best type of propulsion is H2 heated by a thermal molten salt U-233 reactor deriving its fuel over 30 days from a Thorium breeder reactor.

[@xyzyuhee]

@BPS.space have you considered an ADJUSTABLE NOZZLE (whitch can open or close) BELLOW the motor? Just a random guess. wil probably add a lot of complexety and maybe not even work.

[@MatiasLem]

HOLY CRAP I interned with that guy! Small world

[@robinbiskupic2639]

One option for a model rocket that can take-off and land propulsively you could try integrating a longer tube mount for two motors with stops so that after the initial engine burns out on ascent it can then eject the first motor and load a second motor for landing.

[@robinbiskupic2639]

Also one way of throttling a solid engine is using a variable iris over the exhaust opening of the engine to increase or decrease the exhaust velocity (it may also potentially improve the efficiency of the engine overall).

[@vrendus522]

To replace the top fins to the rocket, one needs a thruster that is based on a large thing washer plate, with a very small exhaust groove groove stamped so it goes out in similar fashion to the hands on a clock. This flat plate washer, should be set on a pivot, to where a set of actuator arms fires on command laterally, as the rocket descends, with the actuator, pivoting the ring to fire at certain request times. This is a very simple design, but you must either add a second rocket, or bleed off thrust somehow from your main rocket motor. You can still use the find, as they catch a lot of air, however a second source of thrust is indicated here. Good luck

[@ashokgoswami9670]

You the best teacher of space

[@jackpeterson1909]

I think you should make a course. I really want to make this one.

[@maxnye5693]

That's not your friend - that's your long-lost brother

[@CromoPaleoShow]

12:38 WHAT WAS THAT THAT FLOATED UP BEHIND HIS HEAD!!!!!! GHOOOOOST GHOOOOOOOOOOOOOST

[@CarlosAM1]

What are you reffering to?

[@nandomendoza8780]

I would like to know what software do you always use ? Please. Thank you for teach me about rocket launch and landing. I am starting a design and build a rocket. That is why I want to know what software you use and in which pages you buy the pieces, I would appreciate it. Thank you my friend.

[@TechHelpGuy6]

Hey man! I'm new to your channel but will catch up. :) Everything seems awesome and exactly my kind of content! Do you simply use retail purchased solid rocket motors or create your own? Thanks and keep up the great work! Godspeed!

[@jmstudios457]

He uses commercial propulsion no systems. Usually Estes BP or Aerotech APCP

[@tack9571]

Hypergolic liquids are your best friend in terms of in-flight restart. The only problem is that you'll be poisoned.

[@macmaniac77]

What about using Cold gas thrust vectoring? Dry ice in a bottle and variable thrust exit nozzle to the TVC. Provide just enough thrust variance to compensate for the solid motor variation. Also great work I would love to try to build one of these, thanks for the inspiration

[@williamforbes6919]

Better yet, put it around the rocket casing to reclaim heat losses and put more energy into the gas thrusters. Liquid CO2 under pressure probably would be the easiest to work with. Refill from paintball tank

[@nandomendoza8780]

Mr Banner where do you design the rocket in 3d? I would like to install the software. Thank you so much and successfully Mr Banner.

[@andrewjknott]

Multiple "A" rockets commanded to start simultaneously may not start at exactly the same time, creating asymmetric thrust and rotation. The effect could be exaggerated if there is a thrust-spike in the rocket's profile like was shown for the "F" motor. Definitely a failure mode that should be considered.

[@BradGroux]

This video just saved me at least $84,000.

[@truegret7778]

Hybrid - polybutadiene, LOx (400psi), helium (8kpsi) to pressurize the LOx ..... throttle the LOx (main challenge is a cryo-valve). Start the motor with TEAL (TriEthalAlumina) to burn the polybutadiene to establish the grain.

[@Siamect]

Most serious rocketeers are using hybrids so don't shy away from that just because someone says it is complex. Hybrids are way simpler than liquids. Nitrous oxide is commonly used in racing cars so there are components you can use from racing shops. And take a look at the video "How hard can it be..." where they got a rocket to 50000ft in three weeks from project start to final crash.

[@jeffvader811]

An interesting alternative to chemical propulsion might be steam propulsion. Which is where extremely hot water under high pressure is stored in a tank, and when a valve is opened, the water flashes to steam and expands through a De Laval nozzle. These systems can offer an Isp between 75-110s according to the Berlin University of Technology, which is comparable to black powder motors, with the additional benefit of being throttleable and relatively easy to develop. Source: articles.adsabs.harvard.edu//full/2004ESASP.557E..14K/0000014.001.html

[@maxenceg3314]

Why not use a thrust deflection system with a solid propellant engine? like thrust reversers on planes

[@km5405]

might be difficult without special materials like carbon ablator, the exhaust of a solid rocket is intensely hot and has slag in it as well

[@stefanklass6763]

for this scale, you might be able to work with Steam (High pressure, super high temperature water injected into a lava nozzle). It would basically be a very easy to work with, very cheap liquid monopropellant. The drawback is that you have to invest a lot of development into the tank, as it will have to hold a lot of pressure and high temperatures (up to 300°C) while being as light as possible. There are high temperature matrix materials that would enable a composite tank. The only other option I can think of is steel, aluminium is too weak at those temperatures.

[@anjanakathuria4194]

You can use smallest rocket motors by applying then on the top of rocket and firing then when rocket tilts that much which can't be controlled those small motors can be applied all around the rocket cylindrical body and can be fired when needed by a programmed computer.

[@user-dr2pg8fk2i]

Would there be a way to use an actuator, and a low profile stainless steel cone cut in half (clam shell closing) as a thrust out method of controlling the landing burn? Basically 'throttle' the engines vertical Dv by sending more/less of the thrust out sideways.

[@sonnyburnett8725]

Not to be a Debby Downer but how would you get the outboard motors to ignite in a timely manner? Maybe a pressurized air bottle that’s servo controlled with the nozzles at the top of the rocket for the lateral control. Like you say, lots of ways to do it.

[@Skukkix23]

How about change the nozzle of a solid booster? should that not impact the thrust?

[@FelipeGonzalez-le5jv]

4:27 "Catastrophic auto-ignition" "That'd be bad" ahahahahahahah

[@eccentrickiwicreative2962]

Hi Joe. Could you use a pneumatic cylinder in your motor mount system in such a way that you dumped air out of the cylinder quickly to bleed energy off the motor and almost modulate the output? A bit left field but it might work

[@andrewreid9511]

Will you ever run through designing the rockets in CAD? Do you use Fusion 360?

[@michaelstern1945]

Looking forward to some great content.

[@CharlesGinzel]

is there any mechanical way the force of a single solid rocket could be "managed", perhaps via a variable nozzle? also, was wondering during the video if peroxide and catalyst could be a simple enough liquid rocket?

[@BPSspace]

A variable nozzle would be extremely hard to make at this scale. The throat diameter for many of these motors is just a few mm; controlling that accurately would require very high precision($$$). Cosine throttling is another interesting option(gimbaling multiple motors out to reduce the vertical component of the force), but also increases complexity and cost per flight. Plus you end up needling full 2 axis control on each motor, otherwise any slight misalignment on either motor will induce insane roll on the vehicle. The mass moment of inertia on the roll axis of these rockets is so low that super tiny imperfections can induce a high roll rate. Peroxide and a catalyst are an option, but are undesirable for the same reason hybrids are. Lots of plumbing involved if you want throttle and shutdown control, increased mass, complexity, general risk, etc. If you're gonna be a bear, be a grizzly. If you're gonna deal with lots of plumbing, go full liquid bi-prop.

[@WILLS98]

Obviously cost is a huge factor if you scale up and use more f-15 engines surely the thurst output comes closer to average? then if you ran a 4-6 configuation you could fly 2-3 up and light 2-3 to land?

[@Thorgon-Cross]

A while back I built and tested a regenerative cooled bi-prop engine in the size and thrust range you are looking at using, it is a little rusty now but if you want I will clean it up very good and send it to you so you can test a pre-tested engine before building your own. While I never flew the system it was about the size of your model. I never flew it due to using Gas O2 I could never get the fuel/O2 mix right, should be easy using Lox. Right now I am doing the last bit for a 5KN Ethanol/Lox engine and have learned a lot about doing it cheap and safe. Would be glad to help however I can to keep your project safe. (My 5Kn has cost under 1000$)

[@1kuhny]

A lot of what charlie said would be requirements if you were planning on going to space with full scale rockets. Honestly you probably won't need to use cyrogenics if your intention is just to propulsivly land. On top of that, the charlie also seemed to completely disregarding the fact we are talking about amature, small scale engines.

[@michaelwoodhams7866]

I'd have liked to see more discussion about choices of liquid oxidizer. Could you do a pump-free pressure fed LOX hybrid where you use a heating coil in the LOX tank to generate pressure? This could give you some degree of throttleability, but I expect throttle response time would be horrible.

[@joydeepmohanto780]

I love space and rockets.

[@cbadcruiser]

You could probably use a solid rocket with a variable nozzle diameter like on the back of an F-18 or F-35 fighter jet. this could allow the rocket to change the amount of thrust that the rocket produces with a constant rate of fuel usage. This will also give you more control over the thrust than the 4 small rockets on the sides.

[@jackeldridge1319]

What about Ethanol75 and HTP? HTP doesn't have the problem of boiling that LOX has, and Ik it has been used successively in flight with RP-1 on the Black Arrow rocket. If you clean your tanks right surely that would save alot of complexity right?

[@gabrielfinertie4775]

What about sawing the nozzle off prefab solid boosters and having a nozzle that can actuate its geometry to control thrust?

[@Robin7654]

i would have two ideas on controling solid rocket motor "trust": - some controllable airbreak in the ehaust - light more then one motor simultaneously at an slight angle: pitch inwards so they point parallel to increase thrust. outwards so they point against each other to decrease thrust

[@MrTheOldWasp]

Just out of curiosity. What is the viability of using a thrust reversing system that is used for jet engines to adjust the downward force of an srb

[@TURTLEMMC23]

I'm thinking a ducted fan would be suitable for small scale to perfecting balance and landing. Then swap out motors. And you would have throttle.

[@thelittlejacob1]

Would it be feasible to use 'clam shells' that close in from two ends at the nozzle to redirect the thrust? Somewhat like the panavia tornado.

[@htevo80]

The fire ball from the delta 4 is from it running hydrogen through the engine during startup to prevent oxidation not from hydrogen leaking through the metal.

[@willierants5880]

This is sounding epic.

[@drumfromhell]

Hi can you recomend a site, or forum for beginners?

[@PRN4VY]

But maybe dont use liquid fuel but a mechanism that can tilt the thrust sideways in two opposite directions, decreasing or even disabling vertical thrust and aiming it sideways. It won’t tip over because it would give equal thrust in exact opposite directions. Just a thought i dont know if its possible cause you would need something that can stand the heat of the engine. Make sure it is divided right because otherwise it will tip over at landing. Hope you can use the idea or atleast get a other idea from this suggestion.

[@blakeramsey3373]

I believe that is what the first guy he was talking to mentioned, but I am also looking into doing this for my rocket.

[@matrix777able]

Hello many years ago my uncle and myself designed built and fired a scale model of the F1 using camping fuel and liquid O2 it never flew but did fire awesomely . Unfortunately I have no pics or video of the events . However the plans and ideas are still around . If you like message me ad we can work something out . All the best In your experiments hope to see more . Ps parts now are actually cheaper than you think small pumps stainless steel tanks and fittings are not as bad as you think . Check out Swadege Lock fittings . We use them constantly in the oil &gas industry as instrumentation

[@jonasholtwick5542]

Awsome projekt! Keep it up!

[@Papershields001]

Would it be possible to vector the constant thrust of a solid to recreate throttling rather than go into all this complexity of moderating propellants? Use Bernoulli’s principal, more thrust smaller nozzle, less thrust-open nozzle.

[@Papershields001]

Kinda like a thrust reverser on a jet.

[@erik6690]

A simpler idea for your consideration, instead of using more motors, have you considered just using what you already have and introducing max amplitude short period servo doublets into the decent if/when needed? I'm not sure how many degrees you can gimbal, but the percent of trust reduction during the doublet would be slightly less than (1 - cos(max_gimble_angle)). Good luck however you go about it!

[@mrtnmit]

To effectively throttle down for landing, you could try gimbeling very quickly in a circle. This will create a spiral of thrust that integrates to less in the vertical direction. Plus it should look cool and might be stabilizing? I think your gimbel mechanism needs to be made faster and lower latency to really nail this. You might rethink the gimbel design to be less like normal rockets because your model rocket thrust forces are so much lower. Can you mount it to rotate?

[@jozefvindis4926]

What about hydrogen peroxide with catalist ? Isn`t that the fuel behind rocketpacks and ARCAs aerospike ? Wouldnt that be more feasible for hobby rocket scale ?

[@shaazmaknojiya4580]

Where do you get the 3d model files for the rocket or how do you perfectly recreate a falcon 9 in fusion