Building a Lego-powered Submarine 3.0 - balloon and compressor

čas přidán 11. 09. 2021
Depth control is done with an air-filled balloon and a Lego-compressor. Steering is done by turning the propeller direction with the help of linear magnetic coupling. Otherwise it's more of the same as before. Swimming pool and lake tests at the end. Enjoy!

Displacement: 2.35 kg (5.2 lb)
Test depth: 6 m (20 ft)
Hull: glass jar (IKEA 365+ 1.7l), plastic lid
Balloon: latex water balloon for kids
Motors: 2x Lego PF L-motor (88003-1), 1x Lego PF Servo motor (88004-1)
Compressor parts: Lego pneumetic pump small V2 (bb0875), Lego pneumatic switch (bb0874), Lego Gear 24 Tooth Clutch (60c01), Lego Hose Pneumatic 4mm (21825)
Magnetic couplings: K&J Magnetics D34-N52 neodymium magnet, TapeCase 423-5 UHMW Tape
Propeller: Lego Propeller 3 Blade with 24t Gear (2740c01)
Radio control: 27 MHz controller dissembled from a toy submarine (Zantec Mini RC U Boot), L298 H-bridge to drive motors
Power supply: 9V Lego battery box for the motors, 3.7V Li-Po for the radio
Pressure sensors: Lego Manometer (64065), Jolly Logic Altimeter One

Note: The depth control I use here is called RCABS or Recirculated compressed air ballast system.

Previous subs:
1.0 piston ballast for depth control
2.0 propellers for depth control


  • That's nice video

  • Amazing ❤️❤️❤️

  • wow

  • amazing!!!!

  • Amazing !!!

  • 11:21 the fish eat the go pro

  • Wow! So cool

  • Next: building a passenger plane out of LEGO

  • Who else awaits the day that this guy makes a lego airplane

  • You are a genius.

  • When I was a kid, playing with bionicles, I would take the really loose "axles", put it between my teeth and twist so that it stayed in place better. Just cutting up the outsides of it to produce more friction between the axle and the piece I needed it to stay in helped a ton (especially with their swords). You could probably find another method to use besides your own teeth, but I think it could help out a lot in those situations where you really don't want them to fall out!

  • Cara eu tenho um canal uma olhada lá

  • Muito maneiro submarino você é mesmo um gênio

  • Lego actually made 4 units long axle that don't slip out so easily, it is not at all that pricey to try and get hold of them.

  • (11:42) "Captain scared 'em out of the water!!"

  • Окунь в шоке xD

  • 10:49 fish >@.@

  • Genial…👍👍👍

  • 👏👏👏👍😍

  • So he loads up a jar with birdshot to get it to dive. Aight

  • I don’t understand what happened at the last minute of the video

  • And here I was thinking my bionicle moc was impressive I love this dude stuff keep it up

  • what you know about rollin down in the deep


  • Jumpscare if there is a body underwater.

  • If what when balloon blast in under warer how you get your sumren

  • This is the most stupid, useless pile of crap I’ve ever seen on CS-tv.

  • You know the dude is a born engineer when the difficulty in maintaining a depth from the balloon is a 'feature' lol

  • This is cool as fuck. Also, I am an idiot.

  • Faz mais vídeo como esse aí porfavo

  • This is awesome. I saw someone printing boats, they used syringes with tubes, connected to a servo arm to act as a ballast. Super simple and genius. Like building subs with legos. Genius.

  • No words, other than AWESOME 😎

  • I can't even imagine how scared captain was

  • Where did you buy that lego

  • What did he get hooked on at the end?

  • Лол ,подлодка из спасателей )

  • where are you getting all these stuffs

  • I still am not grasping the depth control, is the balloon pulling it up or is the act of pulling a light vacuum in the main chamber causing lift. of course on a different note magnetic drive from dry side to wet side, just like the D5 pumps in my PC water cooling. the impeller on the wet side is driven magnetically.

  • The "Captain" part kills me hahaha

  • Almost lost a sub, lol

  • theres no way youre human, this is some alien intellect right here. love the vid tho!

  • Got to love the interested Walleye.

  • You don't need a pressure vessel. Just fill the mechanical/electrical Lego compartment with mineral or vegetable oil instead of air. Oil is incompressible, non-conductive, and boyant.

  • Optimising for maintainability over manoeuvrability Vs block ii.

  • Ahven vaa käy kattoo et mitä vittua mun kotona tapahtuu :D

  • 10:51 For anyone wondering, that fish is called a perch

  • BUILD A BIGGER VERSION OF THIS… or upgrade this one! Great video ! Keep it up

  • Keep on going, your pushing the limits of Lego and it’s awesome!!! Genius work

  • that was amazing

  • 11:10 the fish looks interested for your submarine

  • Could you explain why inflating the balloon changes the depth? Isn't it just putting air that's inside the container into the balloon? I'm sure the solution is obvious once you understand the mechanics behind it. I'm just not understanding it atm.

    • @PyramidSchema thanks 🙂

    • The air weighs the same whether it is in the balloon or the container, but when the air is in the balloon the balloon expands, increasing the volume of the vehicle and the amount of water it displaces. When the volume/displacement increases but the weigh remains the same the vehicle rises, when the volume shrinks but the weight remains the same it sinks.

  • I love how the whole video is an experiment, that even the failures are documented. Interesting watch! Keep it up

  • That fish photobomb at the end 😂 nice work m8!

  • Say goodbye when the balloon is gone ;)

  • I'm too slow 🐌 This balloon gets the oxygen from the container, right? Sooo the total volume of the oxygen is the same all the time, it's simply a question of position. Sooo why then with the balloon submarine goes up? 🙃 it's the same volume as before, what happens?

  • Next time he will launch space Lego rocket

  • You sir, are a genius. Was not prepared for the magnet usage.

  • I search for subwoofer and youtube show me this after 2days. BTW great work!

  • This is so impressive, your issue with buoyancy (coming from a diver) will be purely because of the fact that you are using air to control depth. The pressure will completely throw off your buoyancy because you are at such a shallow depth that the pressure change is so great. The only reason scuba divers can use air to control their depth and it work is because we go much much deeper than this so the pressure change isn’t as great if that makes sense. This is why you’ll notice that as the submarine becomes more and more shallow the speed it comes up at increases even though you don’t add any pressure to the balloon, there is really no fix for this as it’s down to pressure and not the design but this was a really impressive video none the less!

  • This is so amazing i wish i could learn how to do all this i feel like i have the drive i just need guidance great job 👏🏼

    • @Homuchog Homa maybe it is but the things you can apply it to

    • Это просто ерунда.

  • Sorry but can someone explain to me how inflation/deflating the balloon makes the sub go up or down? Isn't the amount of air within the sub constant? Its just pushing the air from the hull into the balloon. I know I'm wrong but I don't understand how. Thanks!

  • Let s go to america


  • What's with the tape? That's creating even more resistance for the the magnets to spin, you really don't need it.

    • The translucent tape is low friction tape. The other tape is to keep the magnets in the gear, and they don't need to spin.

  • This is so cool please.keep it up

  • Just waited for a long time! Let me try to make the same submarine for fun.

  • Liz ,elle zi le ,et,’z lz les lzo

  • He should claim a lego engineering degree

  • so much Fish hear

  • Plzz next time make a little larger submarine with lego people in or Captain and his crew

  • “ I know thats not what I think it is” “ A 4:25”

  • Is that even Lego man ? 🦵 oh

  • Adorable fish!!!!!😂

  • that fish looked confused as hell

  • No one: Boys at 3am: 0:35

  • Now you need to make one with a breaching mechanism

  • I was here before 10 million

  • Okay i

  • eyyy a fine video to display boyles law too with the balloon expanding as it rises due to the lessened pressure from the water outside

  • wonderfull work !

  • You should make a lego airship what has working propellers and it has a large helium balloon

  • mans brain is bigger than thanos gaundlet have power with +1 crystal

  • I'll just pretend that I know what's happening...

  • Why did I reply 4:02 - 4:07 over and over again 🥴🤣

  • i was expecting when you put it into the river for the lid to get caught on a rock and pull itself open. i guess that wouldn’t’ve happened given the water pressure, but still.

  • 2 bar works up to 10(!!!) metres, you did not count it atm pressure

  • Where did u fine that balloon? I need it for reasons

  • It's getting there it's getting there!

  • I love how u used magnets

  • Cyclops: *”welcome aboard captain. All systems online.”*

    • 10:44 Cyclops: *”multiple leviathan class predators detected.”* dude there just minnows.

  • Am I the only one that noticed the samurai sword at the bottom of the river?

  • That fish wondering out what a jar’s doing in the water though

  • Awesome!!!

  • this guy so smart

  • I wanna see him make a lego car that goes real fast.

  • 10:50 fishie =]]]]]]]

  • you should rename the video to “how to get new subscribers”

    • 11:02 Fish: “Ayy lmao” Great project btw, I’d like to see bigger, upgraded version which can go deeper with gopro inside the submarine 😃👍

  • You could look into adding a little automation using NXT. Make a program that takes water pressure and puts that into adjusting the balloon ballast to maintain depth. Then up and down will be change depth, not change bouyancy, while bouyancy is regulated automatically to maintain the set depth.

  • This video is so complex but the way he goes about producing it makes it seem so simple. Love this keep it up my dude!

    • First you use full auto in buildings and now you watch one of my favorite youtubers wth man