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...
Just straight into action. No intro, no sponsors, no bs. Love these kinds of channels
Fr
can u recommend any other channels like this boss
@@nissanoo0393Primitive Technology, Cutting Edge Engineering Australia, Matthias Wandel, Code Bullet
Yes🎉
@@nissanoo0393primitive technology but instead if lego it's nature
the fact that you are testing propellers makes me wonder if you are planning on revisiting your Lego submarine.
kinda seems like an anual tradition at this point
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.
There is a point where cavitation becomes an issue, right? And you get that ultra-loud collapsing bubble thing...
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.
@@GerinoMornahead flank; emergency speed. warning! vessel cavitating; excessive noise!
@@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.
@@mikieswartEject decoy!
Bro's the top lego engineer 🗿
I wish it had 3d lego propellers
“Bro-“ Brainrot
@@muffinconsumer4431 ok bro
@@Malfin_L Bro said ok bro
@@muffinconsumer4431 ok bro
top tier data analysis, im fully satisfied
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
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.
@@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.
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.
Good idea with the grams per Watt. I added that comparison to the blog. brickexperimentchannel.wordpress.com/2024/04/13/lego-propellers-water-thrust/
Just a little warning, these results are valid at 7V, closest to that is 6x rechargable AA batteries.
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. 🙂
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.
Helicopter helicopter
Paaaara kofer paara kofer 🗿
You guys are 3 years late.
@@Nomaditishelicopter helicopter
Badger badger
Yes, Papa?
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.
Anybody else find this really weirdly relaxing? Just a quiet video with no dialogue and some experimenting
It's just like childhood lego experiments in your room
Just like Primitive technology. (The OG, not the horrible ones with music and click bait building "underground pools"
Gotta go tell my gf that 15cm is indeed considered huge
Nah bro, that's massive
😂😂😂
My man trying to teach us mechanical engineering and thinking we wouldn't notice
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!
He is studying for the next Submarine!
Nahh that's wild why😭
@@Bocchi-the-wideI bet some of the components on that submarine were made of Lego.
@@Bocchi-the-wide He is talking about the Lego submarines BEC has made.
its crazy how much more power some of the much smaller ones put out in comparison to the larger ones
Really educational!
Next we need to know which design is the most efficient: thrust vs. power draw BTW: good work!
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/
Props to you for doing these experiments.
Hehe
As propellers are tested at zero forward speed it is more useful to be compared in term of "figure of merit"(thrust/shaft power)
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!!!
THIS is peak content. Densely packed with information. Good testing procedures. Great usage of graphics. Legos!
Wake up BEC uploaded a new video
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.
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!
props for this test and the editing
Man the editing here is hella clean, very nice video, and the processes were very clearly laid out which is fantastic
Thank you for going over the set up for testing too.
This is so thorough that I can't even think of something to add! Great job!
Thanks for all the time and effort for great data!
Fascinating as always
Cool Lego experiments, man! I hope they get better and better every day with each and every video you make. Awesome job, man! 👏🏻 👏🏻
this is incredibly in-depth and i appreciate your deligence
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!
Never a dull upload with this channel that’s for sure 👍
Very cool results and very thorough test procedure!
Wow, that is incredibly thorough testing. Well done!
Everything about your videos are so efficient and informative
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.
Captivating video. Love all the graphics you showed
I appreciate how scientifically rigorous and well documented this is. Good experiment 👏
Fantastic video, as always. I would have loved to see some efficiency comparison as well (power/thrust), maybe next time :P
The instrumentation an attention to detail is great, data can be fascinating stuff.
This is amazing data collection/analysis
This is lovely research ❤
Huge props to this channel!
now this is the answer thati never thought to question, very interesting results.
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.
Nice video, like your Lego techniques a lot
you have not even finished the vid yet
Very nicely done!❤
This was absolutely fascinating
You mean FANscinating?
Awesome. I would love to see some lego impellers. Or, better yet VSP-style cyclorotors.
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.
This feels like a college project for a fluid dynamics class. Well done!
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.
id love to read the research paper you make from this
How does one acquire so much red technic pieces?
eBay.
Fascinating.
This is gonna be very useful on my cars!
Nice to see the old ZNAP wheels being given a chance! I still have a lot of that stuff somewhere.
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!
Crazy cool research!
Surprisingly advanced methodology
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.
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 :)
You can *really* see the difference in directional thrust from the ones with an actual aero/hydrofoil shape to the blades, wow.
I really would like to see the input power that each was driven at
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
Performance curves of lego propellers... top tier content right here.
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!
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.
But no clue how you can create such a test structure.
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
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.
There are too many variables, but it's very nice and detailed and arranged very neatly and meticulously making it easy to understand
wow, as a engineer, this is greateful to see, the definition of experiment, so clean so practic, woa
This is like Project Farm but for Lego. This man must also be protected at all costs.
Would have loved to see a toroidal propeller in here! Very nice video.
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...
would be interesting to see a graph of wattage vs thrust for each prop at ideal gear ratio. I know the V/A were shown on screen but i think it would be neat for any future projects in this style.
Volts * Amps = watts
That level of comparison and analysis is heads and shoulders above all these KZhead "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
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.
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.
So detailed.
Make working replica of engine using vacuum
0:19 the trust in that was so good, it literally made the piece come off.. 😂
Are the x-axis labels in the bar plots from 5:50 to 14:40 labeled incorrectly? The setup at 3:22 shows the gear ratios ranging from 25:1 to 1:5, but the bar plot axes go from 1:25 to 5:1.
Darn it! The list of gear ratios from 3:22 to 3:50 is incorrect. Everything else is right, including chart x-axis labels and the ratio you see at the bottom left during tests.
Aivan mahtavaa! Ylänappi kiinni ja käsi lippaan.
good video! very thorough! i'm glad the classics work so well! do you think the ninjago ones would work better with the nosecone?
BEC IS BACK 🔥🔥🔥
What accounts for the thrust difference in direction of spin, with the props built symmetrically?
I love that somewhere, someone is going to find this incredibly useful for their own project
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.
Wow, quite the deep dive (no pun intended). I had no idea there were so many different propeller options. I assume this is part of a larger series of experiments to optimize a Lego boat or submarine? My only disappointment is you didn't make a 10-speed transmission, to avoid having to change out the propeller so often. Or even a CVT to optimize the RPMs even more.
I'm sure some academic paper regarding hydrodynamics will reference this video.
I'd love to see a test of which of these could generate enough push to propel a boat!
Now do some Lego Ocean Gate pressure testing lmao
Can you plot propeller comparison by efficiency? grams thrust per watts (Volt x Amp) power input?
I would have liked to see power consumption graphed across all fans, and this way efficiency (thrust per watt?) could be seen. Or was the power consumption the same in all setups?
Amazing!
I'd definitely like to see an efficiency curve, with amps versus thrust!
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.