Lego Propellers in Water (worst to best)

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  • Опубліковано 3 тра 2024
  • 22 Lego propellers are tested in a water-filled container. Which one provides the most thrust? Enjoy!
    2 non-Lego propellers are also tested for comparison.
    Test method: a Lego Buggy motor (5292c01) and 7V input voltage. A weight scale measures the thrust in grams. Multiple gear ratios (from 1:25 to 5:1) and both directions of rotation are tested for each propeller. The test bench is explained in detail starting at 1:46.
    Note: the list of gear ratios shown from 3:22 to 3:50 are incorrectly presented as inverse ratios. Sorry about that.
    The results can be read in my blog:
    brickexperimentchannel.wordpr...
    0:00 propellers worst to best
    1:00 RESULTS CHART
    1:46 TEST BENCH
    4:22 TEST PROCEDURE
    5:44 6041 Propeller 3 Blade 3 Diameter with Axle Hole
    6:08 4745 Propeller 2 Blade Twisted
    6:40 92842 Propeller 3 Blade 5 Diameter
    7:12 non-Lego boat propeller - Joysway 2-blade P1.4x40mm 83 series
    7:51 30332 Propeller 3 Blade 9 Diameter
    8:21 4751c Propeller 4 Blade 13 Diameter without Studs
    9:02 2952 Propeller 2 Blade 9 Diameter
    9:27 64683 Technic, Panel Fairing 3 Small Smooth Long, Side A
    10:10 Lego liftarm propeller 2-blade 14x9 45-deg
    11:05 18592 Propeller 3 Blade 13 Diameter (Ninjago Airjitzu)
    11:39 41325 Propeller 4 Blade, for Flying Model Helicopter
    12:26 2740c01 Technic Propeller 3 Blade with Gear 24 Tooth
    13:10 non-Lego drone propeller Diatone Bull Nose 4 x 4.5
    13:51 89509 - Propeller 1 Blade 14L with Two Pin Holes and Four Axles
    14:41 COMPARISON TEST: 2 vs 4 blades
    14:58 COMPARISON TEST: short vs long blades
    15:23 COMPARISON TEST: 30 vs 45 vs 60 pitch angle
    15:49 COMPARISON TEST: narrow vs wide blades
    Music:
    Heaven and Hell - Jeremy Blake
    • Heaven and Hell - Jere...
  • Наука та технологія

КОМЕНТАРІ • 435

  • @BeTheGr8
    @BeTheGr8 20 днів тому +1539

    Just straight into action. No intro, no sponsors, no bs. Love these kinds of channels

    • @justinarseneau4450
      @justinarseneau4450 15 днів тому +1

      Fr

    • @nissanoo0393
      @nissanoo0393 13 днів тому +1

      can u recommend any other channels like this boss

    • @BeTheGr8
      @BeTheGr8 13 днів тому

      ​@@nissanoo0393Primitive Technology, Cutting Edge Engineering Australia, Matthias Wandel, Code Bullet

    • @gilangvirgiawan2780
      @gilangvirgiawan2780 12 днів тому +1

      Yes🎉

    • @abdelrahmanmekky7011
      @abdelrahmanmekky7011 12 днів тому +2

      ​@@nissanoo0393primitive technology but instead if lego it's nature

  • @drake52
    @drake52 20 днів тому +431

    the fact that you are testing propellers makes me wonder if you are planning on revisiting your Lego submarine.

    • @rukirgaming
      @rukirgaming 19 днів тому +23

      kinda seems like an anual tradition at this point

  • @BenjaminMarshallScienceMan
    @BenjaminMarshallScienceMan 20 днів тому +849

    It would have been cool to only have the audio from the under water camera, that way you could hear the noise difference between the small and large propellers. In both watecraft and aircraft, small propellers have the trade-off of making more thrust per unit-area, but being significantly louder. That is one of the main reasons that fighter jets are so much louder than giant passenger aircraft despite having a fraction of the engine power, and why nuclear submarines utilize HUGE propellers that spin very slowly.

    • @GerinoMorn
      @GerinoMorn 20 днів тому +55

      There is a point where cavitation becomes an issue, right? And you get that ultra-loud collapsing bubble thing...

    • @BrickExperimentChannel
      @BrickExperimentChannel  20 днів тому +572

      I just listened to the pure underwater audio. You're right. Smaller props are louder. :)
      By the way, that propeller camera was outside the water container. But I had a separate waterproofed Lavalier mic to capture the underwater noises. What you hear on the video is a 50/50 mix of the sound underwater and above it.

    • @mikieswart
      @mikieswart 20 днів тому +74

      @@GerinoMornahead flank; emergency speed. warning! vessel cavitating; excessive noise!

    • @BenjaminMarshallScienceMan
      @BenjaminMarshallScienceMan 20 днів тому +40

      ​@@GerinoMorn Cavitation is caused by a rapid drop in pressure on the trailing edge of the blades, in aerospace the equivalent phenomenon is called 'boundary layer separation', which is the same thing that causes aircraft to stall and lose lift. As far as I'm aware it's simply an issue of your propeller moving too fast for its given blade pitch, so the only solution is to slow the propeller down or reduce pitch, meaning it needs to be larger to make the same thrust. Of course, the larger your propeller is, the faster the tips of the blades are moving at a given RPM, so scaling the size only goes so far.

    • @kennethmoureau5123
      @kennethmoureau5123 20 днів тому +20

      @@mikieswartEject decoy!

  • @Themanhimself000
    @Themanhimself000 20 днів тому +775

    Bro's the top lego engineer 🗿

  • @theo123-cookie
    @theo123-cookie 20 днів тому +1116

    Helicopter helicopter

  • @koray8820
    @koray8820 20 днів тому +236

    top tier data analysis, im fully satisfied

  • @Username-qx9gk
    @Username-qx9gk 20 днів тому +277

    Gramms per Watt would have been useful, but with the gears you also arrived the sweet spot for that motor. Although "static thrust" numbers could be very different to those when boat and prop are both moving fast through water

    • @ionstorm66
      @ionstorm66 20 днів тому +19

      To be fair I doubt a Lego powered boat is going to move fast enough the dynamic thrust will be too different then the static thrust.

    • @Elias-eo1vh
      @Elias-eo1vh 20 днів тому +30

      ​@@ionstorm66Maybe true, but it would be interesting to see how the different propellers would perform when it comes to top speed and/or efficiency, while the larger props generated a considerable amount of thrust, they also create much more drag and resistance when mounted on a moving boat.

    • @ABaumstumpf
      @ABaumstumpf 20 днів тому +1

      Yeah would be very interesting. But there are the current-numbers and the voltage seems pretty stable.
      @@ionstorm66 There is no need for high speeds for significant difference to arise.

    • @BrickExperimentChannel
      @BrickExperimentChannel  18 днів тому +59

      Good idea with the grams per Watt. I added that comparison to the blog.
      brickexperimentchannel.wordpress.com/2024/04/13/lego-propellers-water-thrust/

    • @Papinak2
      @Papinak2 17 днів тому +3

      Just a little warning, these results are valid at 7V, closest to that is 6x rechargable AA batteries.

  • @etepeteseat7424
    @etepeteseat7424 18 днів тому +69

    While I enjoy your build-up-to-the-best-bit style, I want to commend you for the intellectual honesty in getting directly to the showing off all the variations in this large-dataset case which otherwise might have had a very long build-up; not a second wasted, and once you'd shown the most clickbaity part of the video, you investigated each case further. Very respectful of your audience's time, thank you. 🙂

  • @Psychodog_
    @Psychodog_ 20 днів тому +66

    I love these kinds of videos. Good old empirical science. Test a bunch of stuff, note the result, analyse, learn. Great resource when making boats, planes and helicopters.

  • @torpid5092
    @torpid5092 19 днів тому +54

    Anybody else find this really weirdly relaxing? Just a quiet video with no dialogue and some experimenting

    • @papirus00000
      @papirus00000 16 днів тому

      It's just like childhood lego experiments in your room

    • @KapitaenAwesome
      @KapitaenAwesome 4 дні тому

      Just like Primitive technology. (The OG, not the horrible ones with music and click bait building "underground pools"

  • @lwpeden5
    @lwpeden5 20 днів тому +17

    I loved the freeze frame on each propeller followed by their dimensions. Made me feel like I was watching a heist flick where all the characters with special abilities are being introduced.

  • @j-7005
    @j-7005 20 днів тому +52

    He is studying for the next Submarine!

    • @Bocchi-the-wide
      @Bocchi-the-wide 20 днів тому

      Nahh that's wild why😭

    • @andrewpinedo1883
      @andrewpinedo1883 20 днів тому +1

      @@Bocchi-the-wideI bet some of the components on that submarine were made of Lego.

    • @user-uu8ep1il5w
      @user-uu8ep1il5w 12 днів тому

      ⁠​⁠​⁠​⁠@@Bocchi-the-wide He is talking about the Lego submarines BEC has made.

  • @rekire___
    @rekire___ 20 днів тому +43

    My man trying to teach us mechanical engineering and thinking we wouldn't notice

  • @KiriMantiss
    @KiriMantiss 19 днів тому +13

    Had to stop and re-watch at 0:20 . I legit had thought it was a comically edited failure because of how smooth that piece just gently sank down.
    Love watching allt he test and trials you come up with. Keep up the awesome work!

  • @hermaeusmora4874
    @hermaeusmora4874 20 днів тому +54

    Gotta go tell my gf that 15cm is indeed considered huge

  • @IdealIdeas100
    @IdealIdeas100 20 днів тому +20

    its crazy how much more power some of the much smaller ones put out in comparison to the larger ones

  • @JushuaAbraham-sj2xl
    @JushuaAbraham-sj2xl 20 днів тому +16

    As propellers are tested at zero forward speed it is more useful to be compared in term of "figure of merit"(thrust/shaft power)

  • @e1woqf
    @e1woqf 20 днів тому +24

    Next we need to know which design is the most efficient: thrust vs. power draw
    BTW: good work!

    • @BrickExperimentChannel
      @BrickExperimentChannel  18 днів тому +12

      The non-Lego drone propeller wins that comparison. It gets 60 grams per Watt. From Lego propellers the white long panel 64681 wins it. :)
      brickexperimentchannel.wordpress.com/2024/04/13/lego-propellers-water-thrust/

  • @KingOfDams
    @KingOfDams 20 днів тому +10

    Really educational!

  • @JoXDDFive
    @JoXDDFive 20 днів тому +6

    your videos are fantastic, from the editing, building puzzles solved to the top tier data analysis all in an easy to understand presentation WITHOUT saying a word!!!

  • @peacekeepers_error
    @peacekeepers_error 20 днів тому +71

    Wake up
    BEC uploaded a new video

  • @duncanfreeman5436
    @duncanfreeman5436 17 днів тому +4

    THIS is peak content. Densely packed with information. Good testing procedures. Great usage of graphics. Legos!

  • @ResidentIT_
    @ResidentIT_ 18 днів тому +1

    i cant describe how much i love this channel. good, interesting test with good usable results. nothing is over the top and is a very relaxing watch. cant wait for the next sub video!

  • @Maccaroney
    @Maccaroney 20 днів тому +3

    Great video and i love the editing. Makes it really easy to watch.
    Would love to see these blades spun up really fast underwater for fun and maybe to find the failure modes.

  • @The-creator-of-good-videos-15
    @The-creator-of-good-videos-15 20 днів тому

    Cool Lego experiments, man! I hope they get better and better every day with each and every video you make. Awesome job, man! 👏🏻 👏🏻

  • @phillipbuck6104
    @phillipbuck6104 19 днів тому +6

    I appreciate how scientifically rigorous and well documented this is. Good experiment 👏

  • @sage5296
    @sage5296 14 днів тому +1

    Man the editing here is hella clean, very nice video, and the processes were very clearly laid out which is fantastic

  • @hedix13
    @hedix13 19 днів тому

    This is some incredible editing! Plus the effort in collecting the data itself! I know it's just Lego propellers, but I enjoyed watching the video. Thanks!

  • @rumblehansi
    @rumblehansi 20 днів тому +6

    props for this test and the editing

  • @lerikhkl
    @lerikhkl 18 днів тому

    This is so thorough that I can't even think of something to add! Great job!

  • @catmage
    @catmage 5 днів тому

    Wow, that is incredibly thorough testing. Well done!

  • @doubledarefan
    @doubledarefan 18 днів тому +2

    Props to you for doing these experiments.

  • @compi3882
    @compi3882 13 днів тому

    TBH I love how you just got straight to the point, and saved the details for later. Everything you needed to know, followed by everything you want to know.

  • @motorhorn
    @motorhorn 20 днів тому +3

    Fascinating as always

  • @dogvetusa
    @dogvetusa 20 днів тому +2

    Thank you for going over the set up for testing too.

  • @lincolngolladay
    @lincolngolladay 18 днів тому

    Thanks for all the time and effort for great data!

  • @puddinhead99
    @puddinhead99 16 днів тому

    this is incredibly in-depth and i appreciate your deligence

  • @TheElMexicano
    @TheElMexicano 20 днів тому +1

    Never a dull upload with this channel that’s for sure 👍

  • @Zero-ry2rc
    @Zero-ry2rc 20 днів тому +1

    This was absolutely fascinating

  • @breakfingers
    @breakfingers 18 днів тому

    Captivating video. Love all the graphics you showed

  • @goobydoo9278
    @goobydoo9278 18 днів тому

    Everything about your videos are so efficient and informative

  • @JosephsDesign
    @JosephsDesign 20 днів тому +1

    Very cool results and very thorough test procedure!

  • @edcramer6475
    @edcramer6475 19 днів тому

    The instrumentation an attention to detail is great, data can be fascinating stuff.

  • @DonLuca27
    @DonLuca27 20 днів тому +1

    Fantastic video, as always.
    I would have loved to see some efficiency comparison as well (power/thrust), maybe next time :P

  • @r4ryder388
    @r4ryder388 20 днів тому +5

    How does one acquire so much red technic pieces?

  • @jackmalcolm
    @jackmalcolm 17 днів тому

    This is amazing data collection/analysis

  • @DonVigaDeFierro
    @DonVigaDeFierro 17 днів тому

    Huge props to this channel!

  • @M0torsagmannen
    @M0torsagmannen 20 днів тому +1

    now this is the answer thati never thought to question, very interesting results.

  • @mhas9110
    @mhas9110 20 днів тому

    This is lovely research ❤

  • @Matthias-499
    @Matthias-499 20 днів тому +10

    Nice video, like your Lego techniques a lot

  • @greatraven3839
    @greatraven3839 16 днів тому

    This feels like a college project for a fluid dynamics class. Well done!

  • @MrGustavier
    @MrGustavier 20 днів тому

    Fascinating.

  • @timehunter9467
    @timehunter9467 17 днів тому

    Nice to see the old ZNAP wheels being given a chance! I still have a lot of that stuff somewhere.

  • @Eequality72521
    @Eequality72521 20 днів тому +7

    I really would like to see the input power that each was driven at

    • @NeinStein
      @NeinStein 20 днів тому

      The data is there: power is voltage times current. So e.g. at 12:10 it's: 7 V × 0.78 A = 5.46 W

  • @Irskin
    @Irskin 20 днів тому +1

    You can *really* see the difference in directional thrust from the ones with an actual aero/hydrofoil shape to the blades, wow.

  • @Bayoll
    @Bayoll 20 днів тому +2

    Surprisingly advanced methodology

  • @BenjaminGoldberg1
    @BenjaminGoldberg1 20 днів тому

    Awesome.
    I would love to see some lego impellers.
    Or, better yet VSP-style cyclorotors.

  • @HigginsObvious
    @HigginsObvious 20 днів тому +1

    Woah awesome results! Its been a while since I did any fluid mechanics, but I wonder if the biggest propeller wouldn't get better results in a larger test container? 1cm clearance seems like it could cause drag issues that might be making it look worse than it is.

  • @rhgamehamel6350
    @rhgamehamel6350 20 днів тому +3

    Make working replica of engine using vacuum

  • @JeremyMcCrearyTechnicalLEGO
    @JeremyMcCrearyTechnicalLEGO 13 днів тому

    Excellent static thrust tests! Hoping you have some working LEGO powerboats in the works.
    During my LEGO powerboat heyday (see channel), tested all existing LEGO props and several easily adaptable non-LEGO props with methods much cruder than yours. The 2-blade 4745 turned out to be the best performer in speed trials, where many factors other than static thrust also come into play.
    Longer hulls with twin outdrives powered by their own L or XL motors were nearly always fastest. Buddies and I handily won the 2015 Brickworld boat drag race with such a boat fitted with 4745 props. If race rules had allowed us to sand the 4745's slab blades into airfoils, we'd have won by a much bigger margin.
    Real marine prop blades have airfoil profiles to add forward lift to the thrust generated by simply deflecting water aft. No LEGO prop blades had such profiles at the time. Also no LEGO counter-rotating pairs, which meant lots of propwalk.
    When not restricted by race rules, we always used 52-55 mm 3-blade counter-rotating props made for hobby-shop RC boats. No LEGO prop could come close in speed trials, with or without blade shaping.
    Naval architects consider the matching of hulls to powerplants to props something of a black art. Ditto for LEGO powerboats. The key is to arrange for the boat to come to max speed just as the motor's hitting peak mechanical power near 50% no-load shaft speed. That's where gearing becomes critical. Lots of guess-and-check involved.

  • @WoLpH
    @WoLpH 20 днів тому

    For the 64683 Technic, Panel Fairing, you could try variable pitch and see what pitch works best.
    The tests are absolutely awesome in any case! I love it :)

  • @OcelotTheGreat
    @OcelotTheGreat 17 днів тому

    Very nicely done!❤

  • @Nikolai_The_Crazed
    @Nikolai_The_Crazed 11 днів тому

    This gives you a great idea of how well each propeller does under their respective optimal conditions, but what I’d like to see is a data set where all the propellers use the same rpm and gear ratio. That way we can see how the variation of those two factors changes the results. If they’re all taken from the same baseline first, then it gives a frame of reference for their performance under optimal gearing and rpm. It highlights what effects small compromises can have on performance. Someone might use more compact gearing for a smaller project, and get different results because of it.

  • @theoozmachine
    @theoozmachine 20 днів тому +1

    It would be nice if you could make explained videos for some concepts you usually use like gear ratios, torque, and other such engineering concepts for us non engineers to understand

  • @jarrettbellboy
    @jarrettbellboy 8 днів тому

    Something about the #6041 fan that is so nostalgic. It was used in so many early 2000s wacky sets in underwater, space and plane sets in both earth tones and wild highlighter transparent colors.

  • @LutraLovegood
    @LutraLovegood 19 днів тому

    This is gonna be very useful on my cars!

  • @peterrogulla7726
    @peterrogulla7726 11 днів тому

    At first i thought it was just like any good LEGO channel. Then i saw the "Biltema" tachometer, that confirmed my thoughts. Jokes aside, this is great content and i absolutely love the seriousness!

  • @kingofdambreach68
    @kingofdambreach68 20 днів тому +8

    *That's great, my friend. I tried Vortex experiments like yours!!! IT'S quite interesting* 🤗🤗🤗🤗🤗

    • @numberlorebut
      @numberlorebut 20 днів тому

      Your experiments are also very cool

    • @hams_cuties
      @hams_cuties 20 днів тому

      I love both channels. So fun and cool 😋

  • @silverground3670
    @silverground3670 15 днів тому

    There are too many variables, but it's very nice and detailed
    and arranged very neatly and meticulously making it easy to understand

  • @Atilolzz
    @Atilolzz 20 днів тому

    Crazy cool research!

  • @TheWinjin
    @TheWinjin 14 днів тому

    That level of comparison and analysis is heads and shoulders above all these UA-cam "engineers" that just eyeball the propellers. Looking at you, everyone with 3d-printer who just made something that looks a bit like the MIT toroidal propeller and tried to make comparison videos out of it.
    There's content and there's scientific content and I think we can see the difference

  • @Jamesonfp
    @Jamesonfp 19 днів тому +1

    id love to read the research paper you make from this

  • @shivajoshi9068
    @shivajoshi9068 20 днів тому +3

    it was fascinating to see the difference between CW and CCW thrust may be sorta dependent on the difference of the pitch angles of the 2 sides of the propellers!!
    thank you for making such amazing videos! love the whole thing!

  • @SeresHotes25
    @SeresHotes25 5 днів тому

    That's cool! It's interesting to see, what's RPM that will make make the motor to generate the most power. And then it's interesting to know, what's the RPM, that will make each propeller to generate the most force/power. We can then see the efficiencies in percents of each propeller.

  • @commelinales
    @commelinales 17 днів тому

    So detailed.

  • @STA-3
    @STA-3 20 днів тому +1

    Babe, wake up. Brick Experiment Channel just posted a new video.

  • @RedShift5
    @RedShift5 20 днів тому +1

    This is like Project Farm but for Lego. This man must also be protected at all costs.

  • @CaptainWizard3000
    @CaptainWizard3000 18 днів тому

    For the slippery one that required tape to be solid, you could’ve marked it (with a line on tape and prop) to see how much it rotated (if at all) after spinning.

  • @pigletshut
    @pigletshut 16 днів тому

    That 2740c01 brings back memories. It was "the only prop" on the Technic 8855 prop plane set which I still have stowed away in a closet. How to drive it can be a challenge though.

  • @landfillbaby
    @landfillbaby 17 днів тому

    good video! very thorough! i'm glad the classics work so well!
    do you think the ninjago ones would work better with the nosecone?

  • @Creativity_Sparks
    @Creativity_Sparks 17 днів тому

    0:19 the trust in that was so good, it literally made the piece come off.. 😂

  • @Spyzilla1850
    @Spyzilla1850 20 днів тому

    Would have loved to see a toroidal propeller in here! Very nice video.

  • @zett5729
    @zett5729 18 днів тому

    Great Video. Would be Interesting to see the different performance patterns in active flow. A lot of Props can create really unintuitive thrust when measured in an active flow scenario.

    • @zett5729
      @zett5729 18 днів тому

      But no clue how you can create such a test structure.

  • @3_Bricks.
    @3_Bricks. 15 днів тому

    It is clear that difficult work has been done. Like. 👍

  • @atmhso
    @atmhso 18 днів тому

    Such a good video. My only scientific thought is the size of the container is limiting, in that it bounces the water back towards the propeller and alters the result. Still, minor quibble and probably wouldn't make a significant difference!

  • @vmrajala
    @vmrajala 20 днів тому +2

    Aivan mahtavaa! Ylänappi kiinni ja käsi lippaan.

  • @norbert.kiszka
    @norbert.kiszka 15 днів тому

    4:16 small clearance will cause propeller to generate less drag - similar thing we can observe with ducted fans like in turbofans, winglets in planes and with ground effect in low flying planes.

  • @melody3741
    @melody3741 17 днів тому

    please remember pluber's tape is specifically designed for LOW friction
    if you look at many of the plumbers tape they only perform well at low gear ratios. likelyy because higher ones slip.

  • @monomomonononono
    @monomomonononono 19 днів тому

    BEC IS BACK 🔥🔥🔥

  • @koosnaamloos4291
    @koosnaamloos4291 20 днів тому +2

    I love that somewhere, someone is going to find this incredibly useful for their own project

  • @clssgn
    @clssgn 20 днів тому +1

    With those data, I think you could publish high quality lego engineering scientific article. It should be a thing, lol, getting it peer reviewed would be amazing. 😂😂 but always, so great to see your vids as always.

  • @idowedo
    @idowedo 19 днів тому

    I'm going to sit here in almost silence admiring the time and effort this took you to make, this is incredible.

  • @TheGlitch93
    @TheGlitch93 17 днів тому +1

    Can you try to form supercavitation on some props? Would be interesting to see how much RPM each small/medium prop can handle before it starts to form supercavitation...

  • @ivy7642
    @ivy7642 19 днів тому

    I'd definitely like to see an efficiency curve, with amps versus thrust!

  • @RandomBogey
    @RandomBogey 19 днів тому

    I don’t know what I personally will ever do with any of this information. But, as someone who loves running numbers/data and Lego, I’m down for it

  • @nyananas20111
    @nyananas20111 16 днів тому

    i have a fun lil video idea, a battle ship with like trapdoors on the side wich can eject submarines, and or like mini scouting boats, and maybe functioning remote control cannons, you choose rest, but it would be fun if you made that

  • @jamesgroccia644
    @jamesgroccia644 18 днів тому

    There's another 3-blade Lego prop.
    1x Technic hub w/ 3 axles
    3x 1x2 inverted slope
    3x 1x2 plate
    6x 1x1 cheese slope
    The thin end of the 1x2 slope makes the "scoop" of the blade

  • @bbbenj
    @bbbenj 20 днів тому

    Amazing!

  • @matthew.wilson
    @matthew.wilson 19 днів тому

    Bravo! Next step: A marine "wind" tunnel where you can test variable pitch against flow rate and give us some sweet 3D plots :)

  • @erinkarp
    @erinkarp 20 днів тому

    Impressive!