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Will this toy engine work at full size? (yes)

  • Опубліковано 23 вер 2023
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    Pop pop boats, or putt putt boats are great little toys. But could a life sized one actually work?
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КОМЕНТАРІ • 3 тис.

  • Steve Mould
    Steve Mould  2 місяці тому +289

    But what was that giant duck doing there?
    The sponsor is Jane Street. Fine out more about their internship programme here: www.janestreet.com/internships/?Steve+Mould+September

    • Mr. T
      Mr. T 2 місяці тому +13

      Is that the taskmaster season 16 ep1 duck?

    • Migs
      Migs 2 місяці тому +8

      The duck is to test for sharks.

    • Triple 7
      Triple 7 2 місяці тому +4

      Would it work better with a check valve system? One pipe forward pulling in and the other pushing?

    • Brian Donahue
      Brian Donahue 2 місяці тому +13

      The AI kinda makes you sound like a pubescent teen. LOL

    • Nate Krasner
      Nate Krasner 2 місяці тому +3

      I wonder if the "curse of dimensionality" could have a similar intuitive explanation to the square-cube law. The curse of dimensionality is that as you increase the number of dimensions a volume inhabits its mass moves farther from the center and clumps at the edges of the volume.
      This effect has an impact on machine learning. As you increase the number of "features" in a sample of data, the more sparse the feature space becomes.

  • kowalityjesus
    kowalityjesus 2 місяці тому +4770

    There's a society somewhere in our galaxy where pop-pop boats are the most advanced form of propulsion

    • defenestrated23
      defenestrated23 2 місяці тому +383

      what is the Orion drive but a giant nuclear pop-pop boat?

    • newhek
      newhek 2 місяці тому +202

      @defenestrated23 the pop-pop drive

    • Pixelated Kristifr
      Pixelated Kristifr 2 місяці тому +33

      Pop pop car

    • Splarkszter
      Splarkszter 2 місяці тому +100

      Actually... i think internal combustion engines are a kind of pop-pop boat system.

    • Thinkbolt
      Thinkbolt 2 місяці тому +18


  • Wolf NZ Outdoors
    Wolf NZ Outdoors Місяць тому +585

    Thought they really had built a life-size pop pop boat for Steve to ride but then I saw the rubber ducky for scale and realised they'd simply shrunk Steve down enough to fit in a toy boat...

    • Félix Mervamée
      Félix Mervamée Місяць тому +21

      That explains the high-pitched voice, too! We're onto you and your "AI", sir!

    • Daniel Frost
      Daniel Frost Місяць тому +2


  • Play with Junk
    Play with Junk Місяць тому +510

    Now I know why USS Enterprise has it's shape 🙂 It'a an interstellar pop-pop boat!

    • Patrick Glaser
      Patrick Glaser Місяць тому +5

      I always thought the enterprise a looked funky

    • Siggy Retburns
      Siggy Retburns Місяць тому +11

      Thats what I thought too. But after loosing my eye brows lighting dylithium crystal with a Bic lighter, I kinda lost the enthusiasm to continue with the project.

    • Brian & Sylvia
      Brian & Sylvia Місяць тому +2

      Ha beat me to it

    • Crazy Ghost
      Crazy Ghost Місяць тому +1

      Said like a Legend

  • legendary thing
    legendary thing Місяць тому +130

    when I watched the movie ponyo, I was fascinated with their pop boat. id never seen even a toy of one before the movie, and i wanted one so bad after seeing them driving around their city in one with just a candle powering it. incredible that this works at this scale. so cool

    • jpeg
      jpeg Місяць тому +6

      I was thinking the same. Ponyo got me obsessed with pop-pop boats.

    • grico gary
      grico gary Місяць тому +2

      When tou say ponyo
      Its equivalent of smile to me

  • Roy Griffiths
    Roy Griffiths Місяць тому +22

    An anecdote from the UK. In 1946, I had a tinplate boat about the size of a slipper. In the centre was a small container into which one poured about 20ml of methylated spirits. Around the rim of the container were two layers of smallbore pipe. The two pipetails were soldered either side of the rudder, one being 10mm above the other. One lit the meths ,waited for a few minutes for the water to heat and expand in the top pipe before watching the boat cross the pond in silence. I still have it in my nostalgia box.

  • Evan
    Evan Місяць тому +14

    I would love to see a pop pop boat with many many smaller engines. Like your eight cubes separately, the surface area would scale with the volume. But maybe the medium engine, so you wouldn’t need 1 million of the mini ones.

  • Tristan Cunha
    Tristan Cunha 2 місяці тому +885

    There's two ways to make a human sized put-out boat.
    I feel like this one is the "one horse sized duck" strategy. But I think I'd like to see the "100 duck sizes horses" strategy too

    • DarkestVampire92
      DarkestVampire92 2 місяці тому +101

      Yeah that'd be interesting to see- 100 pop pop boats trying to push a life-sized boat.
      While a normal sized duck watches.

    • Alan Herlan
      Alan Herlan 2 місяці тому +21

      @DarkestVampire92 I think pulling with the pop pop boats hitched up with ropes would work better
      it would be like a carriage except it travels on water and it is hitched up to non-living pulling things

    • tsm688
      tsm688 2 місяці тому +33

      I'm sure you could design a more optimal horse-duck. Without the popping diaphragm, better heat conduction
      At a certain point it would start resembling a steam engine.
      Eventually, it would just be a steam engine

    • Dank Line
      Dank Line 2 місяці тому +14

      They dont make giant batteries for electric cars either, so I think scaling up the boat with the appropriate amount of mini poppers would be worth doing. You could probably set them up to fill easy too.

    • Neil From Clearwater, FL
      Neil From Clearwater, FL 2 місяці тому +3

      @tsm688 Wonder how using a valved pulse tube like in a drip coffee maker would work to improve things by eliminating the extra volume in the steam pot. Using a flow through design like that might improve outflow a bit and a header with backflow preventers using multiple pulse tubes could provide for even higher velocity output through a single final outlet.
      Probably would be highly inefficient though with higher water temperatures at the outlet. Wonder what Count Rumford would do...

  • mr BD eye
    mr BD eye 3 дні тому +3

    My Father and I crafted and sold handmade pop pop boats on a website 20 yrs ago. The boats were called “featherlite steam boats” because they were press formed from aluminum sheets and we included certificates with serial numbers for each one. These were the only pop pop boats with small rudder on the rear. Fun times !
    Although my Father has passed away some time ago I still have the press forms to create the boat hull and top and all parts to braze the engine parts.

  • PsiVolt
    PsiVolt 2 місяці тому +4

    it is a bit strange at parts, but it is incredibly how the audio while on the boat would have been unusable and probably require a voiceover even just a year ago
    but now we can noise-cancel and reconstruct dialogue pretty well given how I imagine the original audio is

  • rocamocha
    rocamocha Місяць тому +2

    It's cool that it works scaled up! At the sacrifice of 1:1 modeling after the source material, I bet this would get better performance in terms of speed if done in parallel with a specific size. If the reservoir size that provides the most propulsion that also has the least amount of weight / water can be worked out, I bet it might be able to go a lot faster. I'm no expert but a V8 pop-pop boat sounds pretty cool.

  • odesseus
    odesseus Місяць тому +6

    "We're very much on the cutting edge of life-sized pop-pop boat technology." I totally guffawed at that.

    • Craig Wall
      Craig Wall 3 дні тому

      Dunning-Kruger writ large...

  • Greg Nason
    Greg Nason Місяць тому +1

    A lot of great theory here. I'm wondering about multiple tanks feeding to single or dual outlook with check valves. Honestly my mind is running wild with multiple ideas. Thanks for the content!

  • John The Cooling Fan
    John The Cooling Fan 2 місяці тому +338

    Yeah, square-cube law really defines the size of some things when it comes to engineering. You can't scale things up too much, and also can't scale things down too much. Some engineering solutions just work best at certain scales. And also various material properties come into play.

    • Iskierka
      Iskierka 2 місяці тому +42

      It can be misleading, however. Vehicles can often get *more* efficient at larger sizes, because they are *not* subject to the cube part - as vehicles are not solid bodies, they are generally "skins" defined by their structural requirements, and larger size (without thicker skins) in many cases means disproportionately greater strength.
      This is why larger aircraft have more range and capacity than smaller - the airframe and system weight scales up only with square law (sometimes less; you don't need more computer for a bigger plane), while the cargo and fuel volumes available scale with cube, giving them enormous capacity for both.

    • Blue Rendar
      Blue Rendar 2 місяці тому +28

      @Iskierka It's just square-cube in reverse, and the point still holds that "Some engineering solutions just work best at certain scales". Same is true for ships btw, which is why container shipping has gotten larger and larger as port facilities become able to accomodate them.

    • Communications 23
      Communications 23 2 місяці тому +3

      Makes me think, wouldn't fitting it with two or more smaller pop-pop engines make it more efficient / faster?

      GOOD GOOD 2 місяці тому +3

      @Communications 23 Yes I think something like that may work , smaller pipes for faster reaction and such. Also maybe the POP bit is a flaw that sounds great as a toy but not effecient. Trains don't go pop to move and they are a steam engine ???

  • David Logsdon
    David Logsdon Місяць тому

    The spring and weight model was such an elegant way to visualize a complex concept. Thank you for such wonderful videos.

  • Raphael Trajano
    Raphael Trajano Місяць тому +1

    Great video Steve! Very Interesting.
    I have been thinking about the analogy you´ve made with the cubes, and it make sense (yeah physics =D ) but what if you used 1000 pop pop boats in a larger one.
    Would you get a better propulsion efficiency, or the result would be the same?
    Thank you.

  • Owen Morong
    Owen Morong Місяць тому +1

    I wonder if the "pop pop" action would oscillate faster if you were in cooler water? Could be cool to try in the winter!

  • Lloyd Domke
    Lloyd Domke Місяць тому +1

    With an inlet and outlet check valve I think you could make it a steam pulse jet. Would need a serious amount of heat input.

  • Dilli Gaf
    Dilli Gaf Місяць тому

    Had a bit of a fascination with these boats and this video was fun to watch with a great educational piece on how scaling up works, doesn't work. Brilliant work and great to see those guys where happy to have you come and test their boat.

  • Uffle
    Uffle 2 місяці тому +1155

    my childhood dreams after watching ponyo have been made real

    • Hashida Tackey
      Hashida Tackey 2 місяці тому +54

      My exact thoughts

    • Atsuto Urao
      Atsuto Urao 2 місяці тому +26

      Exactly what I was thinking!

    • Preston Byrd
      Preston Byrd 2 місяці тому +26

      I watched ponyo in 2020, but I felt the same way.

    • gigglesseven
      gigglesseven 2 місяці тому +53


    • Qui-Gon Joe
      Qui-Gon Joe 2 місяці тому +41

      just need a massive candle

  • msamour
    msamour 2 місяці тому +1

    I was thinking about the inverse square law, and I am glad you brought up the square cube law. I think the two laws are related.

  • Today on the Bench
    Today on the Bench Місяць тому +3

    Several smaller pipes seems like a logical improvement.
    Another thing would be a bit more bracing over the main tank, that likely also don't have to be that dish shape, perhaps something more sturdy could be more efficient.
    I would have gone for a section of pipe with added support rings on its outside. Then added some sheet metal outside it to funnel the flame up around the whole tank, as to provide more efficient heating of the whole thing. And of course clad the outside of the sheet metal in some degree of thermal insulation, as to waste less heat. Then perhaps it could even become a bit more fuel efficient.

  • Remblie Kain
    Remblie Kain Місяць тому +1

    If the heated surface of the larger boat had ripples on it there may be a way to compensate for the square cube law. Subsequently to help the steam cooling pipe function more efficiently it could be oval shaped and have a series of heat sinking fins on it as well these can also help it steer better as well as help the steam cool faster. Finally fins or channels in side the steam cooling pipes can help them collect and diffuse the hear faster as well.

  • Life = 42
    Life = 42 Місяць тому

    I am extremely grateful for all your uploads! Thank you for sharing to the world!

  • Carlos Busto
    Carlos Busto 8 днів тому

    Muy buen video !!!! Yo tengo una lancha que era de mi padre ( año 1950 aprox ) . Yo creo que en el modelo que probaste Puede ser que al expandirse las chapas del tanque , hagan perder presión, y por eso ande mas lento ?? Saludos desde Argentina ,

  • Attempted burger
    Attempted burger 2 місяці тому +380

    a system of check valves to allow it to pull water from the front and expell out the back would probably be another improvement to the design.

    • Space Core
      Space Core 2 місяці тому +23

      I think you don't even need check valves, just a longer tube in the front with maybe a couple kinks to increase resistance so that water flows fast out the back and slowly fill back up from the front

    • Element K
      Element K 2 місяці тому +33

      Very much like a pulse jet engine

    • Kate Cole
      Kate Cole 2 місяці тому +40

      @Space Core tesla valve.

    • Erik Åslund
      Erik Åslund 2 місяці тому +5

      @Space Core How would the water "know" how to choose either path over the other? It's not like your'e going to get ramjet effects at those speeds. If you design the tubing to be direction biased it's considered a check valve, like the tesla valve.

    • Space Core
      Space Core 2 місяці тому +9

      Just by making the tube longer and/or smaller diameter it has more resistance to flow so when the bump happen it would expel more water from the shorter/larger pipe generating a net difference in force.@Erik Åslund

  • Lawrence GT
    Lawrence GT Місяць тому +1

    Would be intriguing to see whether solar heating in a hot location would be enough to drive the engine.

  • Jurassic Jordan
    Jurassic Jordan Місяць тому

    This was something i had always wondered. Thank you for saving me from making a massive mess that wouldn't work.

  • Trevor Seals
    Trevor Seals Місяць тому +1

    What if you used a radiator instead of the big tank to get more surface area for the heat to soak through?

  • Andrew Bevan
    Andrew Bevan Місяць тому

    I was skeptical that these guys were up to the challenge….but then I saw the giant rubber ducky and there was no doubt these guys came to play.

  • itsjim1
    itsjim1 Місяць тому

    Would love to see if a V8 pop pop engine could be made to overcome the up-sizing issues 😂

  • Rob and Joyce Hanssen
    Rob and Joyce Hanssen 2 місяці тому +283

    In chemical engineering, there are concepts to overcome the square-cube law. Instead of a scale-up of a reactor (bigger tank), you can do scale-out (more reactors). In extremis, this results in chip-size reactors with lots of surface area. To bring this into the context of the video, just use 10,000 of the minisized pop pop boats :)

    • Macht
      Macht 2 місяці тому +10

      Thank youuuu. I had the same thought just from understanding automotive engines lol.

    • Tyche Love
      Tyche Love 2 місяці тому +3

      😂 he could ask Boudreau for pointers... lousiana has had a pop pop river parade for over 80 years.

    • Timothy Reeves
      Timothy Reeves 2 місяці тому +1

      Maybe a shell and tube type heat exchanger could be adapted to convey heat to the tubes with the water inside the tubes. A lot of hot air in the shell. I imagine it would have to be pretty hot and perhaps a blower in the shell to increase convection a lot.

    • SnertVR
      SnertVR 2 місяці тому

      I actually had the same thought, but I was thinking of creating chips of microscopic popping chambers.

    • tsm688
      tsm688 2 місяці тому

      @SnertVR too small and capillary effect will prevent them working. I don't think they can be made too much smaller than the small ones already are

  • Yukihuru
    Yukihuru Місяць тому +21

    This is a very interesting and fun experiment.
    In Japan, it is called a pom pom boat.
    It is fresh in my mind that it appeared in the anime "Ponyo".
    I thought it would not work with a scaled-up model, but was a bit surprised to find out that it could work with low efficiency.
    The biggest surprise, however, was their attempt at a full model.
    It's fantastic.👏👏👏

  • Chris Parrett
    Chris Parrett Місяць тому +1

    Interesting, Steve… A point missed by yourself and the others is that a pulsating water engine (PWE) or 'pop pop', 'Tok Tok' etc., doesn't have to have the flat plate. Toy ones only had a flat diaphragm to make an engine noise.
    A simple coil of tubing over the flame works better as the flash boiler, and was used in larger model boats like the beautiful, pressed aluminium 'Miss England' by Victory Industries, sold just after WW2, as well as in many kit and scratch built models.
    The PWE engine works by rapidly boiling the water in the flash boiler, which turns to steam and forces the water in the tail pipes out quickly. As the steam hits the cold pipes, it condenses, while the exiting water providing the thrust carries on moving down the long tail pipes under its own inertia (some small toy 'pop pops' only had a single tail pipe). The moving slug of water's inertia then creates a vacuum after the pressure of the steam bubble disappears, which eventually pulls in water, increasing the cooling of the condensing steam and refilling the tube, and 'boiler' section, with liquid. The coil (or chamber/boiler) over the heat source gets rapidly boiled again to send another pulse of steam down the system as it overcomes the back pressure from the now condensed previous bubble of steam and the drawn in water, which is pushed out to provide thrust (but not a lot).
    A 'full size' PWE powered boat was actually built before WW2, though only a dinghy in size and very slow, it was virtually silent and used to stalk and net waterfowl on a calm pond.
    My late father had a huge collection of old steam powered toys, including a lot of PWEs. Most of the PWEs were small candle or spirit heated 'pop pops', but some commercially sold ones, usually methylated spirit fired, were as big as half a metre long or more.

    VEME TAO Місяць тому +1

    This is the most satisfying followup video I was never even expecting!!

  • Blue_Beep hang-glider
    Blue_Beep hang-glider 2 місяці тому +1

    I would think the simplest thing would be having rows of standard toy motors with a common burner. Lots of small high frequency engines that are already tuned.
    P.S. after your first video I bought these in bulk for Christmas presents (1 for me 😁) they were the most played toy by all, my friends spa-bath had a Navy 🤣

  • Ronyon
    Ronyon 2 місяці тому

    I would like to see this powered by a TLUD filled with wood pellets.
    I also wonder if you could put the intake up front for better performance.

  • BurgerKing FootLettuce
    BurgerKing FootLettuce 2 місяці тому +275

    I love the whole sequence in Ponyo when she enlarges the little pop pop boat and I’m so glad to know it would actually work for real!

    • Nicky OS
      Nicky OS Місяць тому +28

      All I could think of is ponyo

    • Josh W.
      Josh W. Місяць тому +17

      That's the first pop pop boat I had ever seen with Soske (not sure of the spelling on that) piloting the boat!

    • Kalpit
      Kalpit Місяць тому +14

      I was 11 when i saw ponyo. That was how i was introduced to pop pop boats. I kinda wished to witness the same speed and sound as that boat in the movie

    • r1kon The Automator
      r1kon The Automator Місяць тому +2

      Right!! This is the only thing I'm thinking of the whole time lol

    • MrBrineplays
      MrBrineplays Місяць тому +2

      When I saw the thubnail, I was like "Hey that's ponyo!"

  • miinyoo
    miinyoo Місяць тому

    Adorable. Yeah. Tactile physics museums are awesome. I remember going to one is Boston as a kid and had a blast. Wonder if it's still there and you're still able to run around doing real life counter intuitive experiments.

  • mazdaman
    mazdaman Місяць тому

    In the museum there was a tap in mid air pouring out water. I remember seeing this in 1964 at Bingley Hall in Birmingham UK. A lot smaller but to a 5 year old this was real magic !

  • Rakenja Myrs
    Rakenja Myrs Місяць тому

    I just had an Idea, what would happen if you had saucer/plate sized version of this in multiple ( more than one) doing this all at once or in consecutive intervals similar to a piston engine?

  • Lachlan Hunt
    Lachlan Hunt 2 місяці тому +2

    I made one of these little boats as a kid. it was literally just a thin copper tube coiled around a few times and the two ends stuck through two holes in a block of wood that was roughly cut into a boat shape, and a little tea light candle sitting underneath the coils. It was completely silent when operating since there was no reservoir to make noise like yours does.
    I wish I knew what happened to it, but I suspect it probably got thrown away years ago.

    • Craig Wall
      Craig Wall 3 дні тому

      Yeah. That diaphragm is completely unneccessary.

  • Eccomi
    Eccomi Місяць тому

    I watched this Video not only because of the quality content you always deliver, but also specifically because of the non clickbait title. Thank you

  • AquaticBubble
    AquaticBubble 2 місяці тому +312

    As an estonian, seeing such a big content creator visit the small country and seeing a physics youtuber go to ahhaa is really exciting :D

    • Meg.A. Byte
      Meg.A. Byte 2 місяці тому +17

      I got excited too! Tom Scott was in Tartu many years ago and now Steve Mould, that's just great!

    • Roman Pääste
      Roman Pääste 2 місяці тому +2

      My kids went to Tartu with grandma to ahhaa, they loved this keskus (centre) 😊

    • My name is 1 character over YouTube's limit, cool
      My name is 1 character over YouTube's limit, cool  2 місяці тому

      @Meg.A. Byte i remember him getting pulled over by the military there, right?

    • Meg.A. Byte
      Meg.A. Byte 2 місяці тому +2

      @My name is 1 character over UAclips's limit, cool It wasn't in Tartu and it wasn't military but boarder patrol, but yeah, funny story nontheless.

    • minaDesuDesu
      minaDesuDesu 2 місяці тому +3

      I was taken by surprise when he suddenly mentioned Ahhaa. Glad to see our country represented.

  • 1238a8321
    1238a8321 Місяць тому

    At that scale you should try one directional valve. To make one pipe as intake and other one as outlet. Plus, yes. Camera with better stiffness.

  • deafmettle
    deafmettle 2 місяці тому +1

    A mnemonic for remembering which side of the boat is the port side: "There is no PORT LEFT in the bottle". Port is also red which is used to light the ports side of a boat in the dark and in Europe at least red bouys indicate the left side of a shipping channel into a harbour or estuary as you are entering it.

    • steve cummins
      steve cummins Місяць тому

      that port and left have the same qty of letters is how I first remembered it

  • TheZoltanChronicles
    TheZoltanChronicles Місяць тому

    I'm impressed that the thing works at all. Life-sized pop-pop boat races should be a thing!

  • Marleyboy
    Marleyboy Місяць тому

    Thats crazy! I was just asking about this possibility 5 to 6 months ago. Only replies I got was that it was impossible for that scale. Thanks for posting this! Really interesting

  • The Old Fart's Channel
    The Old Fart's Channel Місяць тому +3

    I think several smaller units operating at higher cycles would be more efficient. Might even be able to connect multiple units to one outlet and tune the pipe or even reduce the outlet to increase pressure.

    • MINKIN2
      MINKIN2 Місяць тому

      Was going to suggest the same thing. Like internal combustion engine development.

  • ian Sigman
    ian Sigman 2 місяці тому +416

    I wonder what the speed would APPEAR to be if you sped up the speed of a video of the full sized boat to the point where the frequency of the popper pan matched that of the toy's.

    • Jan Montkryf
      Jan Montkryf 2 місяці тому +32

      Let's try to answer this question with some dimensional analysis. What you're interested in is the ratio (speed of the boat)/(popping frequency). The dimension of this quantity will be speed divided by frequency or (m/s)/(/s) = m in SI units. So the quantity you're after has the dimension of length, and it's not unreasonable to guess therefore that it might scale linearly with the length of the boat. So, if you make the boat (engine and all) twice as large and then speed up the video to match the popping frequency, I'd guess that the boat would be twice as fast.

    • M B
      M B 2 місяці тому +4

      If it’s built to scale and had same popper frequency wouldn’t it appear the same speed?

    • DougSalad
      DougSalad 2 місяці тому +2

      ​@M Bdoesn't that depend on the mass of the boat?

    • Apollo1321
      Apollo1321 2 місяці тому +2

      @DougSalad it does yes, scaling up causes the mass to increase exponentially.

  • Elor Yosnak
    Elor Yosnak Місяць тому

    Id imagine if surface area of pipe is issue, perhaps having a hollow shelled pipe might be the "ideal" solution, or as mentioned multiple thinner onez

  • Adrian Schmidt
    Adrian Schmidt 2 місяці тому +1

    Hats off to the Estonian Science guys! Love your work.

    MOTORBIKE MIKE Місяць тому +1

    👍 ♥ I love that idea! You guys are awesome! 🤘😁

  • N. B. P. Davenport
    N. B. P. Davenport Місяць тому

    Looks like a big success, fuel-efficient too.

  • Chris P
    Chris P Місяць тому

    Would it work better if they used much thicker gauge sheet steel for the diaphragm? Or if they used several smaller diameter motors (3 or 4) if the surface area to mass ratio is a factor?

  • Milad Dilmaghani
    Milad Dilmaghani 2 місяці тому +235

    To somewhat counteract the square cube law, we could use fins to increase the surface area of the water tank, maybe an idea for a future video?

    • Michael
      Michael 2 місяці тому +48

      You would also need fins on the INSIDE of the water tank as well. It's not just heat transfer to the metal from the flame, but also the heat transfer from the metal to the water that is limiting it when scaling up.

    • Hashbrown
      Hashbrown 2 місяці тому +35

      Just use a bajillion smaller engines, heat pipes to the big burner
      You dont build a single giant piston if you want to scale up an ICE, you build a V8

    • Erik Åslund
      Erik Åslund 2 місяці тому +12

      @Michael Heat transfer from metal to liquid water is many times more efficient than that of flame to metal. Unless you create and maintain an insulating layer of super heated steam between the liquid water and metal the water at the boiling point will absorb all the heat from the metal much faster than fins could transfer the heat further up. That's why copper heat pipes are much more efficient than solid copper rods.
      In fact, increasing the area of the metal by using corrugated metal would be much more efficient than metal fins for the same amount of flame to metal interface area.

    • Adrian Sue
      Adrian Sue 2 місяці тому +6

      Do like Train Steam Engines
      instead of one big tank, a series of pipes with the flame all around them.

    • Gusto
      Gusto 2 місяці тому

      Or use that gas and water to power a steam engine or a steam turbine

  • Anthony Edward
    Anthony Edward Місяць тому

    @SteveMould what would happen if you superheated the steam through a series of smaller tubes? Would this increase the thermal efficiency of the life-size boat therefore increasing the speed of the boat?

  • Voiceofreason
    Voiceofreason Місяць тому

    What if you made several small engines that feed into a central pipe? Would that increase efficiency?

    EVELYN FIVE 24 дні тому

    It was my imagination when I was a child to see a full scaled Pop-pop boat.

  • BiscuitPuncher
    BiscuitPuncher 2 місяці тому +2

    So the logical solution would be to make multiple pop-pop engines on a slightly smaller scale, say 1/2 or even 1/8 the size in this video and have them each linked together through an unequal length header so there is always propulsion 🙂
    Good luck with timing tho, haha!

    • Paul Sengupta
      Paul Sengupta Місяць тому

      What about 2000 of the really small ones?

  • Chaz Maxwell
    Chaz Maxwell Місяць тому

    I think 1 thing that wasn't taken into account was the simple fact that area that is heated on the pop pop boat os greater than the area being heated on the larger version. One way to increase hp I think would be use a smaller diameter pipe to increase force coming out

  • Jorge
    Jorge 2 місяці тому +149

    I want a full pop-pop boat engine optimization series. I'm interested in seeing what can be achieved with them

    • Eric W
      Eric W 2 місяці тому +7

      Seconded. This is the real science we need our top minds working on.

    • Colin Davies
      Colin Davies 2 місяці тому +13

      I wonder if pop pop boat races would be a good way to solve some of the issues.

    • Leone Venticinque
      Leone Venticinque 2 місяці тому +4

      I call the support of @Integza!

    • thewesty
      thewesty 2 місяці тому +3

      This made me think about using it like a ram pump. Move some water up a hill for the cost of a fire. With it sitting in the sun it would get started faster too

    • tsm688
      tsm688 2 місяці тому +2

      After a certain point it would just be an ordinary steam engine

  • Frozen Lake
    Frozen Lake 28 днів тому

    Have you considered using Duck-Bill Valves. Light, Durable, efficient at keeping water moving in one direction without back-flow or mixing. Love the videos!

  • 先生CherryPepsi
    先生CherryPepsi 2 місяці тому

    I'd like to see what would happen if you scaled the engine size down, and placed multiple in its place. A 4 (cylinder?) pop-pop engine would be an interesting concept

  • TheRubidium7
    TheRubidium7 2 місяці тому

    If one is not in a hurry, a slow boat like a pop up boat could be provide a very relaxing, romantic and nostalgic sense with classical theme environment in a man made lake or river area.

  • Bryan Schultz
    Bryan Schultz 2 місяці тому +1

    After seeing the original video I was rewatching the movie "Ponyo" with my kids when I realized that they made (through magic) a human-sized pop pop boat in the movie. Ever since then I've though, "Man, it'd be cool to see one of those in real life!" so this video is really cool

  • Stick
    Stick Місяць тому

    So, as per your explanation about the square cube law with the blocks, where there are surface area missing after it goes inside the bigger cube:
    Does that mean that if the big human boat (or even the teddy bear boat) is propelled by 20 or 50 small pop pop boat engine, the boat will run faster?
    (theoretically, we will have 8 small cubes without the surface area diminished caused by the combination into a bigger cube).

  • Random Bogey
    Random Bogey 2 місяці тому +307

    2:25 Honestly kind of surprised no one there put an RC rudder on the teddy bear boat. Or even a fixed/adjustable rudder to make it just go in circles and not straight out on the lake

    • mctripleA YT
      mctripleA YT 2 місяці тому +36

      It probably goes tok slow for a rudder to make much of a difference
      The human sized boat steers by moving the motor rather than a rudder

    • neutronenstern.
      neutronenstern. 2 місяці тому +12

      ​@mctripleA YTIt will make a difference no matter how slow it goes.

      FPVREVIEWS 2 місяці тому +7

      because most of the time it does not go fast enough for the rudder to overcome the wind turning it.. so would only work a small portion of the time.

    • Ari Takalo
      Ari Takalo 2 місяці тому

      @neutronenstern. However they could do a nozzle jet deflector just like waterjet boats have. One probably could make one easily from one of the variants of semi rigid hose and couple actuators

    • Henry Parker
      Henry Parker 2 місяці тому +7

      Realistically it was a prototype to test the scaling ability of the engine, not the full functionality. Likely just not worth spending time on it when you can prove out the theory and move onto the full scale boat.

  • Rowan Hawkins
    Rowan Hawkins 2 місяці тому +1

    I never knew of it in this form, but I used to make little tiny jet boats out of a coil of aluminum tubing that didn't need any special setup to fill all you did was pump water in one and until it came out on the other side without needing a container in the middle. Then you just heated the end of the loop and the water vaporizing expanding, cooling and collapsing was mostly silent. The way i look at it is if your engine is making noise, then that is energy not moving you foreward.

  • spyrolover24
    spyrolover24 Місяць тому

    I wonder if reducing the diamter of the outlet pipes would help increase the speed.

  • Aaron Harrison
    Aaron Harrison Місяць тому

    I think you’d find the boats with multiple pipes interesting

  • ZiggyW
    ZiggyW Місяць тому

    I remember making thse little boats for a science fair in year 5 lol. I didn't have the resevoir part though, it was just a full on looped pipe. Worked great too. I don't remember them being slow, so I think it'd solve that pop pop issue? I also didn't have the noise coming off the boat, since no flex. Maybe next one you could try it with just a looped pipe? Less internal volume to move around cuz well, less area to move in the first place.

  • rvdende
    rvdende 2 місяці тому

    I think increasing the frequency would be the best way to scale the large version, how to do that is a bit tricky.. perhaps you would need many 1000x of the small pop pop engines ?

  • Coffee's Hangar & Work Shop
    Coffee's Hangar & Work Shop 2 місяці тому +139

    I wonder if making a Multi-motor pop pop would work better. With more smaller motors you would get faster cycles and hopefully scale that speed up.

    • Lukáš Doležal
      Lukáš Doležal 2 місяці тому +3

      I think the speed would still not change. each motor would push same amount of water each cycle, so each would push the same distance. I guess the only difference is more power, ie ability to push heavier boat but still the same speed.

    • Anton Liakhovitch
      Anton Liakhovitch 2 місяці тому

      ​@Lukáš DoležalThink of it in terms of Newton's laws - for every action, there is an equal and opposite reaction. Pushing one liter of water out the back of the boat requires significantly more force than pushing one milliliter, and as such will also apply more forward force to the boat.
      As for "pushing a heavier boat but at the same speed" - in this case, "speed" and "pushing power" are the same thing. They're related by F=MA -- so for a constant force, a lighter boat will accelerate faster.

    • Anton Liakhovitch
      Anton Liakhovitch 2 місяці тому +1

      ​@Lukáš Doležal(I think your logic begins to work *if* the boat is travelling as quickly as the water coming out of the engine, but in this case it's a small mass of fast-moving water pushing a heavy boat slowly. However, this might set an upper limit to the speed you can gain by adding more engines)

    • MarmaLloyd
      MarmaLloyd 2 місяці тому +1

      If timed properly this could be cool. Like a cross between a cam and pop

    • Lance Thumping
      Lance Thumping 2 місяці тому

      If he's right about only needing a single pipe then why use a tank at all. Take a bunch of regular pipes, cap the ends, bundle them together and run a burner against them.
      Then it should work like your idea.

  • Elli G
    Elli G Місяць тому

    Always wanted to do this as a full boat just so other people would laugh

  • nikbivation
    nikbivation Місяць тому

    thank you so much for this!! I was dreaming for something like that since you uploaded the videos with the pop pop boat

  • BB Sky
    BB Sky Місяць тому

    It might work better with a boiler system similar to a steam train, where the surface area contacting the water is much larger.

  • Vella's Library
    Vella's Library Місяць тому +2

    I feel like having the "pan" or top part that does the popping made of aluminum or even copper would work a lot better, both since it would conduct more heat, but also because as a softer metal it would be more flexible.

    • volentimeh
      volentimeh 13 днів тому +1

      Top part doesn't need to conduct heat, it just needs to POP! copper will work harden while aluminum will metal fatigue, needs spring steel or similar, possibly a big piston like a sterling engine with a spring return (makes it tunable) but that's not in the spirit of POP!.

    • Vella's Library
      Vella's Library 12 днів тому

      @volentimeh Ahh, thanks for the info!

  • Islam Abou El Ata
    Islam Abou El Ata Місяць тому

    I think that some sort of fast non return valve should be used so that the returning water would be sucked from the front, I think that it would increase the efficiency a lot. Second thing is to find a way to increase the frequency of the engine.

  • Enzo Choi
    Enzo Choi 2 місяці тому +177

    great build! I'd love to see a racing league of these (where people compete optimizing them for more 'horsepower')

    • turgsh01
      turgsh01 2 місяці тому +1

      Sounds like a liability issue. Not everyone is smart enough to do things safely.
      To elaborate since no one here seems to figure out the risks involved... Propane tanks can very easily explode like a grenade if the hoses and whatnot aren't set up correctly. That "grenade" can injure surrounding participants, judges and audience members who had nothing to do with it.
      While I agree that idiots shouldn't be protected from themselves because we definitely have far too many in the world and protecting them is only making it worse, I do believe we should protect the innocent ppl surrounding the idiots.

    • jc Kobeh
      jc Kobeh 2 місяці тому +17

      "hose power"

    • Sam
      Sam  2 місяці тому +41

      @turgsh01 racing REAL cars and boats is wayyyy more complicated and dangerous, and we let any idiot do that worldwide. people die. We still allow it. A pop pop league would be fine as far as safety is concerned.

    • BillAnt
      BillAnt 2 місяці тому +6

      I remember building a similar model boat back in the late 1970's as a kid (may have been Popular Mechanics magazine). Instead of a pop-up boiler, I used a thin copper pipe coil heated with some alcohol inside the boat, and the two pipes out through the back under water. It was basically creating a water jet powered by the copper coil heat exchanger, and the water didn't run out like in this boiler, it only stopped once the fuel ran out. Surprisingly it was traveling pretty fast without making any popping sounds. Long before the internet, simple things got us kids amused. hehe

    • Farmerjohn's CountryLab
      Farmerjohn's CountryLab 2 місяці тому +15

      ​@turgsh01 the more we idiot-proof the world, the more idiots we end up with. The more idiots we have in society, the more ways they'll find to do things dangerously.
      In other words, so what if someone might get hurt in a life size pop pop boat race. Nobody makes it out of life alive anyways

  • Raj Iyer
    Raj Iyer Місяць тому +2

    Steve, try to make the next attempt with one pipe, but with 2 non-return Valves. One at the front of the pipe for water intake & one at the back for propulsion. The 2 NRVs will ensure backward flow of Steam & Water providing impulse during both the intake as well exhaust halves of the cycle.

    • Michael Theoret
      Michael Theoret Місяць тому

      What You devised is literally a pulse jet engine but instead of fuel /air mixture ,Your set -up uses steam /water flow . Very ingenous actually . It would be cool to see such a system get built and tested.

  • Jokerwolf
    Jokerwolf Місяць тому

    That's one of the main reasons why shuttles are so hard to get into space because you have to account for the weight of the shuttle itself plus all the stuff inside the shuttle and Rockets.

  • baianoise
    baianoise Місяць тому

    Imagine a pop-pop boat with a high pressure steam boiler and the exhaust with a turbine, and you'll get a steampunk jet sky !

  • jared longard
    jared longard Місяць тому

    Put check valves at the back of the propulsion vents so they won’t release until X pressure that way the force of the released water would be greater

  • Ireallyreally Hategoogle
    Ireallyreally Hategoogle Місяць тому

    The Square-cube law you mentioned is why bigger rounder animals lose less heat, more volume for less surface area.

  • dont ask me
    dont ask me Місяць тому

    You pointed out that it could have one pipe, but with 2 pipes it could also have the water inlet pointing forwards to pull the boat when taking water in, like an impeller, both pulling and pushing by drawing water through the system. The inlet drawing straight along the center of boat and a central outlet pipe (used for stearing as it is now) might help to keep it a bit straighter too which will reduce drag/reduce decelertation between cycles.
    That would only result in minor speed increases but still ways to achieve more of the potential while understanding how scale (form) impacts operation (function).

  • Praveen B
    Praveen B Місяць тому

    I've always loved that kind of boat I had during my childhood.

  • Intrafacial86
    Intrafacial86 Місяць тому

    I think drawing water in from a rear-facing opening slows things down a bit. I'd suggest having one pipe forward with a check valve that only allows water _in_ and the other pipe backward with a check valve that only allows water _out._

  • Alex Peoples
    Alex Peoples Місяць тому

    I'm curious what would happen if instead you used maybe 6 smaller pops for 1 boat instead of 1 huge one

  • MotorClassics
    MotorClassics Місяць тому

    Can you imagine the efficiency of that contraption

  • Matthew Bartos
    Matthew Bartos 2 місяці тому +111

    Hence why cars have multiple cylinders, square cube law. If you tried to blow up a three liter bottle the explosion is way slower and takes more rotational mass to keep going as compared to six half liter bottles which explode faster and can keep each other moving. This can be applied to whatever engine size you have.

    • coolhand1983
      coolhand1983 2 місяці тому +1

      I was literally just thinking along these principles!

    • Scott G
      Scott G 2 місяці тому +24

      V12 pop pop when?

    • Lucas Lundh
      Lucas Lundh 2 місяці тому +1

      damn this makes so much sense, thats insane. thanks

    • gs425
      gs425 2 місяці тому +6

      Multiple cylinders is also preferred as it allows a faster revving engine than a single of same capacity. Power = torque x speed of course. However their is a limit on piston speed due to materials and lube etc, so using multiple cylinders overcomes this.

    • kallewirsch2263
      kallewirsch2263 2 місяці тому +5

      It is also the reason why kids (eg. in winter) cool down much faster then adults. Their volume, which stores the thermal energy, is in relation much smaller then the surface, which distributes the heat to the air.

  • SimsonFahrer72
    SimsonFahrer72 Місяць тому +1

    Nice project!
    Looks like a competition - how can you move forward with the worst efficiency 🙂

    • Jonathan Tan
      Jonathan Tan Місяць тому

      A propane powered 1 cylinder mud motor would give a much faster speed & better fuel consumption. 😁

  • Julian Saul Dipad
    Julian Saul Dipad Місяць тому

    i wonder if it can be more efficient if they changed the metal plates into a radiator type for more surface area.

  • gLiTcH
    gLiTcH Місяць тому

    I've never heard of this. I'm dying to know what the child's version is! Imagine not knowing and seeing this. 🤣

  • Paul Nix
    Paul Nix Місяць тому

    So if you developed a full sized boat that had a series of small pop-pop engines, each with single pipe setups connected to separate engine chambers that use the same larger heat source? Could you have multiple high frequency propulsion pipes providing more power? Imma have to start making some design sketches.

  • Rude Toy
    Rude Toy Місяць тому

    I am confused! Is there already an efficient propane engine out there?

  • LegendaryKenneth
    LegendaryKenneth 2 місяці тому +22

    Would be interesting to see if it would be more effective to use a large number of much smaller engines, instead of one big one.

  • Vivian Astridge
    Vivian Astridge 2 місяці тому

    A most interesting and unique attempt and congratulations to all involved. This type engine will work using a simple flash tube boiler. It is not required that the boiler should be based on the flexing plate boiler used on toy boats. Using a flash tube boiler would also make it possible to arrange an efficient heat transfer system as used in industrial flash tube boilers. During the steam car days, most or perhaps all cars used flash boilers as these are totally safe and do not require to be certified as is required for regular water or fire tube boilers. Perhaps further attempts using a flash tube boiler could result in worthwhile power being developed sufficient to propel a person sized boat. I do hope those interested will proceed further.

  • Aldo Valkovich
    Aldo Valkovich Місяць тому

    Interesting support for scientific reflection.
    Obviously for those who, like me, do not have a full understanding of the basics due to limited education😊 (I'm a 76 year old)

  • Ian theinventor
    Ian theinventor Місяць тому

    Wonder if as you scale up the boat you need to scale up the heat required to produce propulsion 🤔