Google translate won't help me write a reply

Tom Stanton lol

I follow you both. It was really cool to see Joe on your channel! Keep up the great work and content guys!!

Or "HOW DARE YOU SIR!"

You low key look like Elon. 😂

Thanks Grady!

I was surprised a simple, naive threshold worked so well!

Yes, exceptionally clever considering nobody else anywhere, ever thought to do the same thing. An original comment for an original idea.

@@alphaforce6998 This feels alot like sarcasm

@@calebsherman886 I think we can build a test rig to help determine that conclusively.

Frederick Evans 72 words actually

@@Trxps-_- lol

yup. completely right dude

So much this, pressure regulators are required for any gas system. Micro pressure regulators do exist and the lightest one seemed to be from landefeld. Their R M5 series is lower than 50 grams and rated up to 8 barg(2L PET bottles seem to hold up-to 150psi which is around 10barg, he tests the flights with 100psi) but additional setup will certainly be higher than 50g.

The mass is the problem here. He would probably get less flight time then he would gain from them.

It is a drone. (Or if you mean that man there? He is Superman.).

*JEB NOOOOOOOOOO* **Boom**

What's a "space program"? Some new computer simulation?

Oh hey Ryan M, it's me Ryan M

Needs moar boosterz.

@@alphaforce6998 its fun try it kerbal space program

If it was in space though a little thrust is all it needs, it could actually go quite fast.

Lol

Nailed it

My exact thoughts

Steve Buscemi haha

And he runs like Dr. Evil

This. Thrust comes from acceleration of the fluid. Even better, use the air supply to drive an air multiplying housing instead of using it directly. For those who haven't heard of air multipliers they are industrial devices with no moving parts, powered by compressed air and used to move air for ventilation. The Dyson fan uses this concept.

That entire part of the video was so frustrating to watch!

You can see at 6:22 he uses a converging nozzle. He probably changed the design after being told but didnt explain it in the video.

He does have supersonic flow. Going from 6 bar to 1 bar will give you supersonic flow at the nozzle throat.

He can't have supersonic flow at all, no matter what the gas pressure is. The reason rockets have supersonic is the fuel is burned, producing the shockwave, which is funneled through nozzle.

6:18 he did end up using a converging nozzle

@@Zaros262 but he didn't use the expanding nozzle after the converging section

@@junovzla It likely doesn't reach Mach 1 anyway, so it would actually be bad to have a diverging section.

It should be able to go sonic when the pressure is roughly twice atmospheric.

Thanks for chiming in with what you read on wikipedia. Clearly all it takes for anyone to become an expert on any topic is a cursory scan of wikipedia, and off you go to a comments section to dispense qualified advice.

@@alphaforce6998 Wikipedia is not always wrong, or even wrong half the time, and he never admitted to being an expert. Anyways this not even anything complicated, it's like if the guy was asking what 2+2 is, and this guy replied 4, you don't need to be a mathematician to be able to learn that or even find it out yourself.

@@dapz Well, that's the thing - nobody was asking anything... And he would have first consulted wikipedia's entries about the number 2, addition, and basic arithmetic.

@@alphaforce6998 What seems to be the problem? Looks like the only thing wrong here is your attitude.

"Yes I'm typing this by hand"

@@Faldrian when does this come up? did not see it-.-

@@RCP-1136 19:50

@@RCP-1136 Look for the flight test part. :)

Wow awesome idea For slow motion tuning like a black box for your eyes to see what's taking place or needs to.. u guys are amazing

@@cenabitednbfpv587 Exactly!

yes, muh macmuhface

There is a submarine named boaty mcboatface

muh1h1 mc blank face , comes from the idea that when u insult someone you call them a FUCKFACE! the mc comes from .. mc lovin. so. mc *insert word* face

The creators of a polar research ship invited a public vote to name it. A prank name, Boaty McBoatface, suggested by a radio dj, went viral, and won. But the owners rejected it in favour of 4th place vote, RSS Sir David Attenborough. They did, however, give the name to a small, unmanned research submarine. It's a well known story here in the UK, hence the jokey Thrusty McThrustface

@@hgwells1899 i know the story. I've also heard about a city who introduced a new machine to throw salt and gravel on icy roads and asked the public for names. The winning entry was something like "itsy gritsy teeny wheeny yellow anti slip machiney" :D

Can we be best friends

Most underrated comment on this video! He sure does look like ELON and also trying to do basically the same thing ELON is conducting, which is to say, bringing back and landing a rocket on its own!

i am convinced this is actually the truth. @elon musk. what did we win?

I cannot deny that .. looks suspious

This guy isn't an evil supervillain however

Except Elon isn't an engineer and hasn't really done anything worthy in terms of engineering.

dry ice would definitely similarly very high pressure, a pressure release valve might help mitigate that

maybe chemical gas generator? CaC2+H2O or something like that?

Well spotted! Propane has a density of 493kg/cm3, while compressed air has just 1.2 kg/cm3, that's why using compressed air you need an unbelievable amount of pressure to stabilize anything (rockets/drones/etc., etc.). Please check the propane gas thrusters created 5 years ago by Amazingdiyprojects. He created this system for his steam model rocket motor. If BPS will use propane, booya, we are going to see some serious fireworks. :-)

oh goodness, i just realized what would happen using propane with a solid rocket propulsion mechanism

Did someone actually suggest venting propane for thrust instead of igniting it? We must be at a genius convention here... Maybe you can just power the drone by getting an extension cord and plugging it into itself for abundant free electricity.

Not sure if solenoid valves are that fast

I don't think the valves can move that quickly

Pulse width modulation? If the valves can react fast enough that would work.

​@@arnavjain7564 to expand on why I said relatively, there is an absolute minimum time to open the valve and another time till closed, which will result in a limit to the maximum cycle frequency. I understand this reality. It certainly won't maintain RC PWM freqs, but something alike PWM done in Hz frequencies is what I have in mind. I'd keep the gate on the input, but make it trigger lower. if the input > gate, then the thruster should start a cyclical pulse who's duration is proportional to the magnitude of the input (up to 100% duty cycle for a 'full throttle' command). Many smaller pulses should use the same amount of air as a few big pulses, so I don't think we'd see a huge drop in efficiency or anything. These are test bench questions to answer. In full size rockets utilizing RCS's in space, they don't deal with any of this because they're not inherently unstable balancing broomsticks quite like a wingless thruster in an atmosphere is. The RCS activity looks like a few 'pings', followed by silence as the ship rotates for a minute, then a ping or 2 more to stop that rotation. our implementation would need to differ in this regard to account for wholly different stability circumstances. I also implore Tom to revisit the nozzle. the bell of a rocket nozzle is useless without first accelerating the gasses supersonically with a throat restriction. The bell was also simply too big, in my estimation. The bell of an Estes rocket motor is smaller, and that motor produces hundreds of times the thrust. just saying, possibly a lot more efficiency could be squeezed out by looking back at the de Laval design principles. It is also 3D printed with FDM, meaning the inside is ribbed with a repeating half circle pattern. this will mess up your boundary layer flow which means turbulence which means loss in efficiency and thrust. Tom, if you come up with another nozzle design I can print it with an MSLA machine, threads and all, polish the interior surfaces with a lathe and ship them to you. Otherwise I'd look into acetone vapor polishing the nozzles printed in ABS. I also have the setups for doing this if you need.

@@chrismofer yea a couple hertz like say 5Hz should be possible i think

Smoke! Great idea

smoke and a red led together...

I would like to see heavier fuel, to perhaps set stuff on fire.

why not hypergolics??

@@kadmow Hypergolic fuels are, to say the very least, quite toxic.

@@astrofox2409:yep, I realise.. but... think of the Coolfactor with a hydrazine and di-nitrogen tetroxide mix. Lol. (It was a joke "obviously")

Yep, that guy is looking like Elon Musk and does simmilar things.

Co2 pressures will burst those bottles

@@ipodhty not with a pressure regulator....i think you could have sort of a manifold who let some reactions occurs at a selected low pressure threshold...., by timing the chemical reactions.dry ice with air might be touchy to control in time since it active with oxygen. im no chemist but neutralizing some acid in little timed quantities might be a pretty neat iea .you make the reactions take place one at the time in a 4 thicker bottle that feed the 3 others and have a pressure regulator...Still you will have weight that's reduce in flight to program in the arduino.

The venturi effect may increase the velocity of the gasses, but it doesn't change the mass, therefore doesn't change thrust. The nozzles actually increased the surface area which increased drag which reduced thrust.

Andrew Krause you trade pressure for mass flow. Just what you want. The ducts around the nozzle would work somewhat like the duct around the prop.

@@andrewakrause p=m*v F=dp/dt

@@andrewakrause Yes but the trust equation is a function of mass, flow, and velocity. Thus it would increase.

Try it, let us know.

*face

No dip, Have you ever seen his channel!! "In thrust we trust"

The exact pressure is not critical, so maybe the weight and complication of a pressure sensor can be avoided. If you started with variables for pressure and volume, then you could calculate how much gas comes out of a nozzel during its on period. Updating a remaining-volume variable would enable you to predict the remaining pressure which feeds into the calculation for the next nozzle release. In this way you could compute the pressure to use when compensating for loss of thrust. The arduino board that is converting a gradient signal to on/off might be able to manage this between thrusts.

Are either of you guys control systems engineers?

@Jonny B i asked bcause i had a PLC question

pid values*

less gas more time.time must be scaled !!!!

Yep, he's also using only expanding part of "rocket nozzle". And straight nozzle is not that bad, subsonic flow converges and accelerates in straight pipes because of boundary layers (of course it's more noticable in longer tubes :) )

A CD nozzle requires a heated gas or fluid since it uses it's expansion to accelerate it. However if he heats the gas the container weakens and may melt if heated sufficiently, since the gas is less dense you need a larger container, this grows perpetually and you end up with a big tank that's supposed to fly that but support itself, if he heats the gas outside the tank sufficiently he needs a large heater. It works for rockets because rockets use combustion engines where the combustion occurs outside the tank and because it's combustion at all it's extremely hot.

I think he should consider Venturi Effect in the design of the thrusters. I think something like a Dyson "bladeless fan" air-multiplier would move a lot more air in the intended direction (and increase the moment on the vehicle for the same cost).

That exists, and I believe is called an ejector nozzle(?).

@@perfumedmanatee6235 - yes, thanks for the reminder. I know I've seen this before somewhere...

Yeah if it is windy and the drone is trying to tip the one bottle gets used way more

He looks like some sort of Neanderthal

thought that aswell lmao

his friend looks like baby of Mask and Zuckerberg 😊

I know, right? I realized that myself after a few minutes of looking at him, then it clicked

He might be a elon clone who knows

I think you are right, but the nozzle would have to be super narrow and he would need to calculate the width. I think it's a good idea but it's to complicated to be worth it.

this is a de leval(?) nozzle. tom was on the right track with the bell nozzle, but it's far far too big and only going to decrease his thrust.

Same

for a second I was really surprised

He does kinda look like a young Elon.

Same

Same.. looks very much like a young Elon Musk..

And he took them off when the pop bottles were at 100psi...

@Rick Lokers IF it comes at high pressure, which is not the case here

Yeah, also for any nozzle you want speed for pressure which is why the constricting worked best, though it could probably be optimized a bit further. The exceptions for the energy rule is entropic explosives and low speed deflagration combustion, in essence the actual rule is that the bell nozzle and aerospikes wants supersonic flow of propellant, which in essence mean combustion products.

Wouldn't it work better if he reduced the flow BEFORE the expansion nozzle? So if he used a 2mm supply line that fed into a nozzle that first reduced to 1.5mm THEN expanded to 4mm wouldn't that work better? I'm not sure what the most efficient numbers are but you get the idea, right?

@@leveckfamily8841 Not if the flow isn't supersonic, if it is super sonic there are other reasons to avoid it sometimes like structural integrity, but in general then it's a good idea, in those cases you need a different type of restriction though.

@@leveckfamily8841 the best would probably be a diverging nozzle with a small throat like the one he settled on (≈2mm) and that expands to 4mm or 5mm. Also it would probably be a good idea to sand it smooth to decrease drag/turbulence

It isn't even about holding higher standards - it is absolutely normal to make informed guesses with control systems. It's just that cost of making mistake with rockets is incredibly high. Properly and precisely calculating right control parameters is incredibly complicated and time consuming, for even simplest of cases.

It's sad that he already had the test bench setup to measure minimum thrust at minimum opening time for the valves. It would have been easy to setup a reference table in the Arduino, and given better control at near-zero pitch/roll

would the super cold temperature not affect the pressure capability of the plastic?

He can do the pressure part in software. The computer knows how long it was firing, and he can separately figure out pressure vs time. Then it would of course need to be started at a specific pressure. But it saves the weight. Maybe I just see everything as a software problem because I'm a software developer.

@@TheJohnreeves In this video he already tried adjusting the PID values to vary the release time and didn't work as well as my suggestion would. He needs a hardware-based gradient valve solution that would change based on the relative pressure after it's released more and more.

@@umbra1016 The problem is that flow and pressure are linked when using a fixed nozzle. A pressure transducer linked to the throttle gate value should help though.

You couldn't see the lights especially in day also its just extra weight the motor barely caries current weight

A really high performance turbo might run at around 30PSI of boost. Joe is running 60-100PSI or more for his thrusters. Care must be taken with choosing a valve for a thruster, because they tend to fail if you use more than their rated pressure. The failure modes can be leaks, failing to open, failure to close, or destruction of the valve itself.

@@USWaterRockets they run civics at 60psi

I agree with you,but I see another one say p =mv. F =pt. So its just like the fuel injector.fuel flow decide by the pulse wide . I think it's a easier way to control the force. Bad English . :-p

@@-_-5352 Yes agreed. I was thinking F=mass of air/time But there could be a problem with the amount of time and deadtime of the valve. Your English is just fine. =)

@@USWaterRockets Yes agreed. Keep the valve he has. It's made of metal. Many car BCS are made with plastic bodies and prone to crack and leak over time. On my project car I switched from a PWM valve to a ball and spring type manual one. It holds shut until desired boost is achieved. The boost comes on hard and datalogs show no leaks. Tom should keep the metal ones he has. But if he tries the PWM method he can add a hard cut of airflow once the desired angle is achieved. That minimizes the over compensation. You could even taper by ramping the PWM width and/or time at the end.

Might be hard with the solenoids limited speed

I thought about that as well, but i dont think the solenoids can turn on and off quickly enough

@@oskarkrogsgard3014 I wonder if it's possible to have faster solenoids.

@@luongmaihunggia Most likely is. But they are probably also more expensive. But I think it's easier to make a variable valve though, like the throttle in a carburetor. There is a problem with making air tight though, but I'm sure some clever engineers have already figured that out

@@oskarkrogsgard3014 more expensive and heavier, yes. variable valves like that are available, but also rather heavy for something like this.

I'd say it's a coanda induced ground effect as the Venturi effect is mainly used to describe air pressure's relation to velocity inside a tube or pipe

@@benfillman4049 accelerated air underneath the bottles, making a low pressure, sucking the drone to the ground. venturi effect

@@benfillman4049 dumbass read what you said again

The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. Coanda effect is the phenomena in which a jet flow attaches itself to a nearby surface and remains attached even when the surface curves away from the initial jet direction. You Decide.

@@MrDaewen Phenomena is plural. "is the phenomena" is nonsense. You decide. No, wait. No discussion.

Talk and act like him too. If he sounded like him... then wow.

"Hey they got discount Musk!"

he has his manerism which i think is lame..ok i see that he admires elon musk but..fuck off mate have your own personality

@@chemgreec this comment is so uselessly mean the fuck

I KNOW, the way he moves too it's kind of insane!