Can we reach the Speed of Sound with Lego? 767 MPH Tip Speed! 4k
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- Опубліковано 8 тра 2024
- Warning: High frequency sounds! Following on from the RPM test I attempt to reach the speed of sound using Lego Technic. Breaking the sound barrier!
I’m using 39 Powered up L motors powered by 12 control+ smart hubs!
Extremely fast spinning wheels with exploding Disks!
Thanks for Watching :)
#lego
#experiments
#legoTechnic
#tank
#legocar
#legomoc
#extremebrickmachines
#legospinningwheel
#brickexperiment
#legoengine
#rc
#legoflywheel
#legoclutch
#legoexperimental
#legostarwars
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Lego technic
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Spinning Lego wheel fast - Розваги
Thank you for the positive response to the video everyone! I really appreciate it :)
I’ve just figured away of getting much higher speeds! I feel silly for not even trying this before as i didn’t think it would work originally.
I’ve just hit over 650mph tip speed so hopefully they’ll be a follow up video soon. Thank you
Wow, incredible, over 1000 km/h, thanks for the spoiler ;)
Try to make it lift off the ground
Brick Experiment Channel can go up to 19000 rpm!
@@nathansaldanha5445 He uses a modded Lego motor with the limiters removed and a stronger power supply instead of the Lego issued battery. This channel is strictly Lego.
Sound speed is directly proportional to the square root of the absolute temperature (v = 20.05*sqrt(T) = 20.05*sqrt(t+273.15) ), therefore you can try this experiment in a colder environment. For example, the speed of sound at 20°C is 1235 km/h but at 0°C it is 1192 km/h, a little bit less (4%)
I hope this can help you - maybe, in your next tests you can at least turn you air conditioning on :)
Try a hard drive disk platter. They're kinda heavy but they're balanced really well. I think valve and the losses from it are what's holding you back
I think a CD or DVD could do as well
@@ardwordcross5632 if you really wanna save weight use a mini disk
69 likes and i don't wanna ruin it
I second this. They're also designed to rotate at high speed for long periods of time.
Sadly they are designed to drag air with them (for the head stack) but it's worth a try
Hi thanks for that Joe! I think the balance is the key like you say! I tried some really light paper and it did worse than the normal 80 gsm paper which I featured on here :)
"aluminum foil clearly doesn't work - Let me try... ALUMINUM FOIL."
😂
this is actually my favorite comment on all of UA-cam. Screenshotting for future laughs
Aluminium
Seeing it attempted a third time is what sent me
@@scorpsamusthe 4th time sent me
The fact that all these people in this comment section are being helpful and trying to propose ideas on who to achieve a commun goal is pretty cool and relatively rare. Great video! I want to see the project succeed!
lego wheel go fast
No it's not. If anything youtube comments are obnoxiously positive. What's rare is that they are giving genuinely helpful and thoughtful comments instead of low effort positive comments that could fit onto any video with the either the absolute minimum effort to tailor it to the video, or going way overboard with it but poorly.
@@JasonMitchellofcompsci True. The actual good feedback is what’s surprising
@@JasonMitchellofcompsci Why not have constructive criticism with a positive, encouraging tone?
@@JasonMitchellofcompsci you look like you have an entire phone book of discord “kittens” and their social security numbers written down with a death note hardcover on it
When your tin foil disk exploded, it was experiencing 1400 g's of centripetal force around the edges. Pretty incredible if you ask me.
At this rate, you might actually hit material limits before you break the sound barrier.
He *is* hitting the material limits
@@Rheologist yes but its ye cheep aluminum foil from martwal
@@Rheologist I don't think he has hit material limits yet, tin foil is capable of more but just a thin sheet of it was never going to hold up to such high speeds.
I calculated about 12000g's of force with a speed of 358 km/h and a diameter of 17cm
The rotor has significant pumping losses, it acts as a centrifugal fan. If you sandwich a disc closely between stationary discs it will go much faster, as less power will go to pumping air. That said, you’ll need a balanced, precise and stiff disc for the rotor. Beware that if you use CDs etc. if you reach failure the fragments are vicious. Gluing radial carbon fibre ‘tow’ will improve strength to weight but will be difficult to keep balanced. Pairing with a prop balancer for RC plane/drone props might get you there.
Beware there will be vacuum generated either side of the rotor as it centrifugally removes the air, so side discs also need to be stiff.
in english, air is sticky. cover the sides of the big spinning disk and it will form a vacuum. less air make less sticky.
like when u put ur hand over a vacuum cleaner and the bwaaaa speeds up.
@@emiliaolfelt6370 thank you for the translation
Hey thanks for that info, really appreciate it cheers :)
@@emiliaolfelt6370 thank you for the translation, I cannot speak smart
Is it really supersonic if there's no air, though? 🤔
The problem with using bigger and bigger discs is that if you double the radius you get twice the circumference and twice the speed but the mass of the discs quadruples because the area goes up with the radius squared. So it's probably better to go with a small disc and increase the gear ratio instead
Hey yes bigger definitely made it worse! I need something so thin but rigid :)
Technically it's the moment of inertia which makes it worse. Since moment of inertia is 1/2 mr^2 for a disk it goes up with the 4th power of radius
Why would moment of inertia limit maximum speed? The cause is just air resistance, not mass
@iRian I agree that moment of inertia affects acceleration, but not the top speed.
@@finalstarmandx6644 Top speed is reached when sum of all torques is equal to 0. Here we have 2 sources of torque - engine and air drag. Moment of inertia does not affect any of these.
the tin foil disk slowly disintegrating from the rotational forces at 3:50 was pretty cool. Mach 0.5 is still pretty impressive with lego motors and axles all things considered
Slowly?
Blame it’s diameter
it littrally rips itself apart
This might be something useful which I learned from XKCD:
The edge of a spinning disc can't go faster than the **square root of the specific strength** (tensile strength divided by density) of the material it's made of. So, to get a disk that can spin faster you need to pick a material that has some combination of stronger an lighter.
Graphene. It seems to be the answer to everything nowadays.
Carbon fiber?
@@mOries0795 If I'm remembering how to read my Ashby chart correctly then yeah, carbon fiber looks pretty good. However, I do think it depends on how the carbon fibers are arranged.
@@whoiam5838 Considering how most computer fans just use regular plastic, the shape /structure of the spinning object seems pretty important.
I reckon CNC cut carbon fibre or even GRP might work. CDs as some have said here seem heavy but you'd want to check the maths. Has anyone ever tested the tensile strength of a CD lol (I'm kidding, it's basically polycabonate with a shiny side obvs)
Breaking news: Man built makeshift hypersonic missile using LEGOs making LEGO stock rise 1000%
Fkn military-industrial-Lego-complex...
😂😂 hey there! :)
@@GazRsExtremeBrickMachines hey
6:44 when the intrusive thoughts win
6:50 look at the black pins turning due to the vibration. Thats soo cool! Love it.
This guy and the slow mo guys need to do a collab. Would be awesome to see the vibrations in the object spinning.
It'd awesome to see a video with both channels.
Amazing how the aluminum foil discs tear themselves apart. It would be so cool to see that happen in super slow-mo!
I’d love that too Paul, I’ve been looking for an affordable slow mo camera! Hoping to get one soon, most are silly money.
@@GazRsExtremeBrickMachines Lots of youtubers use Chronos cameras. They'll do thousands of FPS and while they're not cheap, they're a lot cheaper than Phantom. Probably cost less than what you've already spent on crazy-level Lego gear. :P
watch 'CD shattering at 170,000 FPS' by the Slo Mo Guys. Not exactly what you wanna see, but pretty damn close
not that amazing when you can rip it apart easily by hand
It’s because the disk hits the resonant frequency of the material. Once resonance occurs the material experiences amplified deformations and explodes because of it
5:00 the ultimate weed whacker
If you could laminate some aluminum foil discs together so the thickness tapers from hub to edge, that would help keep it from breaking under centrifugal loads. It looked like you'd maybe have enough power for that type if only it held together. Keeping it nearly balanced is critical, though, so my suggestion might be hard to fabricate accurately enough. The low weight of the foil may mitigate that, so maybe worth a shot.
Cool idea
Hi there thank you and that’s a good idea! I’ll keep experimenting cheers :)
6:37 sounds like a car
At 7:15, you can see the black rivets holding the frame, are rotating from the vibration, just thought it was cool
6:24 weedwacker moment
I love how pins spinning from vibration at 7:07
Most people are wrote about the loads but I think an important portion of the power is lost on the plastic axles and gears, their flexity reduces power greatly so maybe a design could adress that, also having lots of rotating things increase the intertia and cause air friction so decreasing the number of gears could work better, maybe some gears can be put in the same axle. Although as I think about it, inequalities of the motors also a problem for the system maybe flexity of gears is a requirement for alignment of all motors.
Hey thanks for that! The one problem is axle strength which is why I need so many inputs to spread the torque load. :)
@@GazRsExtremeBrickMachines For this problem, I think the best solution is steel axles, Legos plastic axles are not enough for this projec
@@teknikadam9001 that would break the entire objective of doing it by legos
4:40
the disc got so angry it destroyed itself lol
you need very aerodynamic "arms", and as few as possible. Try just one "arm", balanced out by a counterweight. And the "arm" has to be propeller shaped, but with a flat angle, so it does not move air. Then try to find the torque vs speed curve for different gear ratios and use the setting with ideal power and construct "arm" length accordingly. And while centrifugal force gets better with increased diameter (if you want constant tip speed), air resistance depends on total area, so a smaller object at the same speed creates less of it.
Hey there thank you for that! Appreciate the input! I may have found the answer! Video soon hopefully :)
@@GazRsExtremeBrickMachines try RC helicopter blades. They are usually well-balanced and are aerodynamic
Actually a flat disk has much better aerodynamic than any arm.
@@escain Better aerodynamics but significantly worse losses from pumping, or in laymans terms literally dragging the air around. An aerofoil shape is ideal, or sandwiching the disk between two static disks to remove the air pumping.
what about fishing line or dyneema
that has incredibly good tensile strenght to weight ratio
2:52… interesting how the aluminum disc shatters under immense centrifugal force. It reminds me of how TheSlowMoGuys did a video about this phenomenon showing amazing footage of what a spinning CD or Record looks like just before it shatters.
Hey thanks for the comment, much appreciated! I wish I had better cameras :)
Was gonna make that exact comparison. Love that video, incredibly educational as well. Was insane seeing the disc warping, with the warp moving at a different speed than the actual movement of the disc
It’s stiff and light and when it changes/folds too much under the immense speed it shatters
The sounds that the foil discs made when disintegrating were amazing! Bit like a cyberman dying 😂
Lol, I wish I had a good camera to see this in super slow mo :)
@@GazRsExtremeBrickMachines you should try to record it on your phone if he is able to do slow mo
aAaAAAAaAaAaAUUuUUUUuUUAAAAAaAaUUuUGGGHhHHhH
wonder what would happen if we just keep adding more motors and eventually make a propeller to try lift the craft
Somebody already did it :-)
ua-cam.com/video/TTui3shLRPk/v-deo.html
Well, would that be a bigger relative increase in power or in weight?
To make a craft you need enough power or lift force to lift the motors up. Or else it's just a high speed fan
If you weren’t behind some kinda of shield, that was pretty ballsy. The Centrifugal force of that rpm range has to be insanely powerful, especially with those weights attached with a string, one blow to the head from a breakoff would be most likely fatal.
6:05 contraption sounds like black mesa anti-mass spectrometer
That ending made me laugh so hard
That disk was like "nope im out, not havin it today" 😂
This is extremely cool! Sound barrier or not, I think you reached a world speed record for Lego.
Did actually reach the sound barrier on the edge of the aluminum foil. That’s why it kept exploding
Achieving the speed of light with lego
5:24 try more things like this, make crazy things that attach and spin on it like that, perhaps try and get such high speeds that it lifts itself up!
6:38 you can see the pins holding the 2nd 5x7 frame spinning inside the pinholes. CRAZY! I liked that
4:09 it sounds like a car!
Same
my i4 honda jazz after I installed a turbocharger:
3:05 United airlines flight 232
💀
American Airlines flight 11
Spinning a bullet to the speed of a bullet and hoping a glove and/or sweater will stop it is my new definition of optimism.
Fun fact: the sound of a whip cracking is literally the end of it breaking the sound barrier. The whip was likely the first man-made object to achieve supersonic speeds, even if only for a small moment
7:55 airplane noises
it might help to stabilize the open end of the output axle. I feel like the primary vibrations caused by unbalanced rotating mass are really holding it back
The foil disc's are actually a great example of tensile strength of materials, and are a great way to show why Tesla's hydroelectric generator would never work on a large industrial sized generator scale. At the time of its creation no materials could take the centrifugal forces. For context the generator had a peak efficiency when spinning at ~45,000 rpm iirc, and when used with a disc similarly sized to our current hydroelectric generators at around 2 meters, the tip would be reaching speeds in excess of mach 13.
8:02 sounds like a propeller airplane
A very valiant effort! But I think you'd need to optimize your rotor a _lot_ more than this to get to Mach 1. Something like a precision machined aluminum flywheel might do it. Also, maybe consider aluminum axles for the last few stages? I imagine they're better balanced, straighter, and will lose a lot less energy to vibration losses as you pass through resonance bands.
3:14 sound like my annoying neighbor car
Yes his car exploded
It like the way the foil one go "AHHH-" on take 3 (3:55)
3:00 Looks like aerodynamic instability.
As you can see in 2:34 you get the highest circumferential speed with small, stiff discs, maybe you can do it with a more stable disc of about 10cm! I keep my fingers crossed for you and thank you for the great content, I can't wait for the next video...
Hey there thank you! I really hope to achieve! Last night I managed 650mph (new tactic I stupidly didn’t try lol) :)
@@GazRsExtremeBrickMachines Wow, incredible, over 1000 km/h, thanks for the spoiler ;)
Model aircraft propellers routinely break the sound barrier (most the of noise you hear on high performance stuff). Those high speed composite propellers are balanced and strong enough to not kill you. Granted their positive pitch means they need several horsepower to achieve those speeds, but you should be able to find something with a shallow pitch. And EDF impeller comes to mind.
Having aerodynamic lessons in my studies, I think that the disk route is the most likely, with stronger disk (not kitchen aluminium foil, but thicker foil from industrial cakes, or sheet metal) and less flexible like paper :
I would say that the linked weights and the rolling bar have the least chance, as they induce a lot of drag, because of the vortexes created behind them.
In my opinion, the disk route is the most likely to work, as the disk, instead of running into nearly stationary air, will create a uniform (if the disk stays flat) boundary layer : a region between the surface of the disk and the stationary ambient air were the air next to the disk is induced in rotation by it and this rotation movement decrease the drag.
The issue with the disks, is the centrifugal force (f(N)=mass(kg)*radius(m)*angular velocity(radians/s=2*pi*turns/s)^2) your disks shattered because the aluminium foil couldn't sustain the tension induced by the centrifugal force, you need a stronger disk, and as we saw, the paper one is too flexible, resulting in it flopping during the rotation, creating a lot of drag.
thanks for the sound warning... my headphones (and by proxy ears) thank you!!
2:11 the ultimate papercut
This video just seems to prove that a bigger diameter is slower. Also, you need to use materials that have a terminal velocity higher than the speed of sound if you want to reach it. Also, the flatter and less warped the disc, the higher the speed it will withstand, before further deforming.
Hey there thanks for the comment I appreciate it! I’m continuing with this right now, I’m getting close :)
7:20 *the mosquito in my room:*
4:55 lets get dangerous
I noticed something really interesting in the "tower assembly" you used in the later tests in the video: the bolts connecting the two segments laterally were spinning in their sockets! Could this be some sort of resonance in the structure, maybe even sapping away energy from it?
Yes, definitely losing a lot of energy there. The whole construction was shaking.
That's so cool! 330 mph is incredible!
Hey thanks Jared! I Appreciate it :)
imagine aliens studying this piece of footage and going, "well this is an interesting way to disintegrate tinfoil "
Watching these just makes me want to go and buy enough to make my own, I fear how much this would've cost. I have enough expensive hobbies already trying to make synthwave. This is so great though, I'm glad someone is doing the Lord's work. There are so many questions to be asked!
Try ironing the paper, it should help to flatten it out and minimise vibration issues
This is a super underrated channel. Love the vids!
Hey there thank you so much! Really appreciate the comment :)
bro im watching this through a screen and this still made me want to stand back
I love how the 17cm one sound like literal car engines lol
From the point of physics, I must tell that to reach the maximum possible speed, sideways from putting all the weight to the center and making maximum diameter, you must minimize the possible air resistance, bc on high speeds it's taking much of the power. That's why you made out only 124 km/h with those lego bars
Hey yes I do agree! The drag was insane on that bar! I’ll experiment with other things in the future :)
@@GazRsExtremeBrickMachines If you actually want to get up to the speed of sound, you might want to look at something like the Busemann biplane for the shape of the thing you're spinning:
en.wikipedia.org/wiki/Busemann_biplane
The problem is that once you get up past about 0.6 times the speed of sound, resistance starts increasing dramatically, up to ten times what you'd expect based on the (already huge) quadratic increase that you see at lower speeds:
en.wikipedia.org/wiki/Drag-divergence_Mach_number
So to get from half of the speed of sound up to the full speed of sound you'd expect to experience 4 times the drag (and require 8 times the power), but instead you experience about 40 times the drag (and require 80 times the power).
Putting weight to the center will only make the disc accelerate faster, not raise top speed.
Well air would create more stopping power, if it encountered the parts which're more far from center, therefore creating longer lever for air to push against
For those of you who don’t know, 0:46 that’s how cars work to get high speed.
ahh yes, he has become so advanced with Legos he wants to make one go faster then some commercial aircraft. Love to see it.
6:22 chainsaw sound acheived 👍👍👌👌
Try it in a vacuum chamber, pretty sure you can do it at reduced air pressure.
Hey thanks Daniel I’ll look into this! I think brick experimental did it so will take a look :)
Wait, I'm sure you can build a vacuum chamber from Lego!
This looks dangerous. I love it :D
Haha thankyou :)
U know ur a scientist at heart when the thing flings high speed bits of metal out at all angles AND THEN U TRY IT 2 MORE TIMES!!! This reminds me of that skid comic about the mystery Lightning lever
30 years later we're going past the speed of light using LEGOS
can you make eletric scooter from lego?
nice vid.
That’s a great idea! I do hope to try this! Thank you :)
Wow! It's impressive that wheels reach such crazy speeds! 😎😲
Cringe
@@Sillybug_ ironic
take 3 is amazing to see how the disc just shrinks
I would also recomend to wrap around the machine a wall .... as you have created for a segment. I am very familiar with turbine burst tests... it is quite surprising the amount of energy even a small mass has at those speeds... awesome vid
4:15 Audi v10 FSI(tm) soundtrack
5:29 helikopter helikopter
That foil spinning needs to be filmed in high speed! Looks like it stretches out, very neat.
You need a thin disc with a large diameter, thicker on the inside and tapering out towards the edge. Use lightening holes to minimize the weight of the disc and reduce the aerodynamic surface area to hopefully reduce drag. Or run it in a vacuum pot.
I have a cheat way to do this, attach a Lego technique piece to a supersonic aircraft:333
That may have took me less time to organise than charge these 72 aa batteries 3 times over lol
Try ceran Wrap (I don't know if I spelled it right). Its really light does not break as easy as the tin foil and if it's a disc it doesn't have a lot of drag. All the ropes stuff suffered from huge drag. I don't think it's possible with the rope because the drag punches them back if you are really close to the speed of sound and they will just pull back and reduce the diameter
Hey thank you for that I’ll look into it! :)
Very entertaining and fun to watch. Thanks for posting this.
I would love to see the flywheel car idea integrated into a form of launch control to assist an electric motor for a dragster build
Damn man that’s sooo fast I found the tin foil so satisfying as it got completely shredded 🤯 keep it up!!!😎👍
Hey cheers Nick! That foil made me jump out my skin the first time lol 😀
You should try to put this in a vacuum chamber to eliminate air resistance. A lot of energy is lost to air resistance espaccially with the disc. I am curious wich speeds you will get to.
This would be great to try cheers :)
@@GazRsExtremeBrickMachines Looking forward to it!!!
But then it’s no longer the speed of sound (which depends on air pressure)
@@jacobsharf8173 so that means that his another challenge is to get speed of light.
Congratulations! Happy 90K Subscribers
Thanks for the warning! I can't handle high frequency sounds, so I'm going to check out a different video!
Can you try spinning a propeller on that thing? Good video👍👌
Yes, but not at hypersonice speeds. A prop would have the highest drag of all the things he tried by a far margin
My next video will feature this! I have an idea but not sure it will work :)
@@GazRsExtremeBrickMachines ok fine😁
I was looking through the comments to see if anyone suggested this. Lol. I want to see it... though you will want to ware a hard face mask with other proper protections. If it fails, it's going to hurt. Might want to setup a stand for your tool and hide under and around something to be safe. Cage will also work.
Vacuum chamber to go even faster?
Sound can not travel in vaccum
Passing the wires to a vaccuum chamber must not be easy
@@cvs8524it can. There’s no air particles for the sound to hit
here i am just getting mad anxiety everytime something goes flying
You should add an aerofoil to the ends of the bar you spun, then calculate how much lift it makes
4:50 You do realise that now you have to make a technic whipper snipper? (Brush cutter for the non aussies)
weedeater
I still had to google lol. A strimmer!!! I do plan on doing this, I’ve even made the end fitting out if just Lego and it cuts really good :)
@@GazRsExtremeBrickMachines excellent, I look forward to seeing it :D
This might be much much harder the closer you get to mach 1. Planes travel at around mach 0.8 because it's the fastest they can go before air resistance just skyrockets. This is your main enemy here. I have a feeling you need a LOT more power to even get tiny things faster than the speed of sound. Plus centrifugal force will be astronomical at this speed as well. I wonder if it can be done though :)
Parasitic drag increases with the square of speed.
The reason airliners stick around Mach 0.8 though is less to do with pure drag and more to do with the shockwaves that start forming creating unsuitable buffeting for control surfaces among other things. Propeller tips can easily break the sound barrier in high performance aircraft, such as the Tu-95. However, again, the shockwaves created by this are undesirable.
Realistically, the mechanical drag of such a large geartrain is what's holding a Lego creation from spinning something up to the speed of sound. There are so many shafts and so many gears and each one of those just compounds the force needed to drive the output shaft.
@@sgthop Yeah you're right, drag increases with the square of the airspeed. But the drag coefficient Cd peaks around mach 1. Which in turn increases the required power by a lot more than just the square. That's what I was referring to. All of your other points are absolutely correct though.
Yep I fear you’re right! At a guess I’d need 10 times the amount of motors continuing on like I did here!
But I do think there’s better lighter things to spin with far less drag which could help! Would be great to achieve with Lego power :)
@@sgthop If you've ever heard a Harvard, or T6 Texan flying they have that really distinctive buzz from the prop tips breaking the barrier- on WW2 era training aircraft :D
@@dentjoener The Wikipedia article on drag divergence says the drag around Mach 1 is up to 10 times what you'd expect. So instead of seeing 4 times the drag (and requiring 8 times the power) to get from Mach 0.5 to Mach 1.0, you'll see something more like 40 times the drag (and require something like 80 times the power).
Goal for the wheel is to have minimal surface and cross sectional area for the least air resistance while being strong enough for speed of sound spinning. The weight does not affect top speed for a given diameter and air resistance, only the time it takes to hit the top speed. Weight will increase moment of intertia, but that only lowers the acceleration of the disc, not top speed.
Also there is a special diameter for each material which gives the highest speed. It’s a balance between
1. extra air resistance of a larger disc
2. Lower RPM for speed of sound
this is some serious lego testing !
I recommend using the buwizz motors they have an output RPM of 2000 !!! Maybe that could help you reach the speed of sound,
Thanks!
I wish I had a few of them Daniel! I priced quite a few up with the hubs but the cost was silly silly money! Mainly the hubs! I’d need about 20 to be more effective than these 39 L motors. :)
Did you consider maybe a disc from an angle grinder? Also, for cutting foil, you might try it with heavier foil with lower tolerance, and a compass, maybe that will help keep it flat
thanks for providing me with spaceship sounds
if you were to ritate the big weed cutter sideways so that the holes are facing the direction of rotation, u would have significantly less drag
I suspect you have quite heavy losses with those multiplication ratios, especially with those 64:8 gears. Using smaller ones will result in more complex drivetrains, but this will be more than offset by the cut in losses. In particular try to avoid using the 8-tooth gear as a driven member.
What kinds of batteries is it using? You can get a bit more power out of Energiser lithium AAs. They can put out a max of 1.7v each.
Unfortunately just 1.2v energiser! they would be great!
Holy… Gosh!
I love his Lego videos.
Halfway through I couldn't stop thinking about how much better results would be if gears we're oiled