Testing 15 Lego Propellers

[@DrEngine]

I have been curious about how the size and shape of a propeller affect its efficiency for a long time. I tested some propellers that I found in my drawer. I hope you find my experiment interesting!

[@SWellWellWell]

It was educational and fun! Thank you!👍👍👍

[@Sonnell]

It was fun, but it felt like it lacked the basic understanding of aerodynamics. I suggest you try the same tests next using smoke, then you'll understand a lot of misconceptions about how these stuff works. Like why the ball did not move close to the propeller but was sped up at a distance, or why non wing like "propellers" did not work.

[@HydroWorldOutlookPrimary5769]

@DrEngine It was very interesting! Thank you! 4:40 As a building tip, though, when building custom-made propellers using LEGO Technic panels like this, try not to build perpendicular to the axis of rotation like you did in this video, as the centrifugal force acts outwards on the propeller blades. What I mean by that is, try using pairs of either the 3L Technic universal joints (for controllable and variable-pitch propellers) or the 3L Technic angled axle connectors to mount the blades parallel to the axle or axis of rotation, and reinforce the blade connections on both the bottom and top halves of the propeller hub. 3L Perpendicular Pin and Axle connectors can be used to mount the blades onto the hub. I've found that this design is much more resistant to centrifugal force and can hence spin at much higher speeds (even ludicrous BuWizz or buggy motor speeds) without breaking apart. I will provide links to the parts I am talking about below. www.bricklink.com/v2/catalog/catalogitem.page?P=42003#T=S&O={%22iconly%22:0} www.bricklink.com/v2/catalog/catalogitem.page?P=32016#T=S&O={%22iconly%22:0} www.bricklink.com/v2/catalog/catalogitem.page?P=62520c01#T=S&O={%22iconly%22:0} Hopefully this helps! :)

[@HydroWorldOutlookPrimary5769]

@@Sonnell The ball did not move closer to the propeller because thrust from the propeller was exerting a forward force on the ball until the force of gravity interrupted the ball's motion (on steeper inclines). And non-wing propellers can work as long as each blade is set an angle, they are just less efficient than propellers with more aerodynamic blade types. Moreover, the propeller failure at timestamp 4:40 resulted from a structural integrity issue directly related to the propeller's design, not its aerodynamic performance. Centrifugal force acted outwards on the blades and overcame the frictional forces that held those blades to the propeller hub.

[@AaronTureRonAbrahamsson157]

Very funny Videos! 😊

[@shizumeru_]

The wind detector falling over was a task failed successfully

[@guilhermesantana5101]

FR

[@panopticonoctopus560]

Your design choice to put the 3 flags along the ramp really drew me in: Flag 1, Flag 2, Flag 3, The Box!!! Loved it ~ thank you 😊

[@DrEngine]

Glad you like them!

[@baitsforyou]

hi

[@abc27iir]

@@DrEngine You need the gear ratio of 1:21.43347050754458161865569 with 40 tooth combine with 24 tooth 6 times so does it improve the result? 0:07 At 0:11 you only reach the gear ratio to 1:12.860082304526748971193416 NOT 1:12.6 because you calculate the gear ratio wrong

[@Slownick]

You have been running some props in the wrong direction. Best test them in both directions

[@stonehengeman]

Also different amounts of power in each run.

[@jessicaclark4350]

go-go gagit pixel reducer 0:01

[@josephbruceismay6832]

OH NO THE PIXELS! WHERE THEY'RE GOING?! [screams in 8p]

[@ChristopherChrisPajor-dp2wj]

Correct directions

[@0G_VR_GAMING]

AAAAA

[@Simple_But_Expensive]

I see several ways this test can be improved. 1) The tilted track means that at the higher levels, the propeller is no longer blowing along the axis of travel. A better setup would be if the track was attached directly to the motor frame, and the entire assembly was tilted. 2) Not all of the tests were at the same distance from the axis of rotation. A better setup would be three tracks, one at the bottom edge of the propeller, one at the center, and one at the top. The bottom one would trap air against the track, while the top would not, allowing comparison. 3) There are no really useful metrics. For an apples to apples comparison, make the track(s) longer, tilt them at 30 or 45 degrees, and attach a scale to the tracks. The propeller pushes the balls up the track, but it is long enough that the ball(s) 7:43 eventually stalls before reaching the end of the track. Measure the distance to get a comparable metric.

[@DrEngine]

Amazing tips, thank you!

[@whatusernameis5295]

also have the same amount of power behind each of the fans instead of changing it. that really messes it up when available power is changing (some of the earlier fans would have benefitted from more power but you didn't give them it then you gave later ones more power) unless you did keep the same number moters

[@MIRGAN33]

Ну ты душнила...

[@thenotoriouscow2063]

You have to tilt the rotor as much as the slope to keep the force and it's vector constant

[@shroomzzz]

+1 for the Hot Wheels track! Such a bummer to spend the time build up something like the 'wheel' only to find it completely ineffective. All AFOLs know this pain. Thank you!

[@cattervr]

7:55 that "flop" made my day! 😂 so unexpected, yet so incredibly funny!!😂😂

[@anadiacostadeoliveira4]

Everybody do the flop

[@jcmagna]

the effort put into these videos is amazing

[@gabrield.8999]

I'm amazed by the success of the first 2-blade propeller !

[@elios7623]

4:21 THAT COUNTS???? hahahha aah omg you got me good

[@Hybridroodragon]

Lmfao

[@jamilaanizou]

Yeah lol

[@isten85]

😂

[@isten85]

I was thinking the same thing

[@Gearz-365]

Another amazing feat of LEGO engineering!

[@spleenjacobson203]

It’d be cool to compare ducted designs! Or maybe even multi-stage setups with progressive RPM on the addition fan stages? Or additional vanes after the fan to create laminar flow, which would increase the distance the air travels?

[@djhagrid300]

More blades doesn't equal more wind. It's actually negatively affecting the amount of moved air by decreasing the efficiency of the vortex. Same reason boats or wind turbines usually only have 3 blades on a propeller. It's a fascinating science actually. I recommend looking it up.

[@Vladimir.VovaSPB]

So, What makes more blades?

[@filgiupo4853]

Absolutely loved this video since I always wanted to know which propeller worked best

[@DrEngine]

Great to hear!

[@LegoWondersOfficial]

It makes me so happy seeing people who are really passionate with lego, and actually post videos frequently ❤

[@ajmc6322]

The wheel is pretty much just a large centrifugal fan which pulls air through the middle and flings it to the outside. You usually see them inside a cowling with one outlet for directing all that airflow to one area (usually inside someplace that needs cooling)

[@DrEngine]

Thanks for the info!

[@ВеликаНадія]

Thank you so much for the informative video! The video quality is incredibly high! I am impressed!!!

[@DrEngine]

Glad you enjoyed it!

[@orangebg3761]

Hey the flaps on the fan you maid is reversed that's why it didn't work​@@DrEngine

[@SergeiKoshman86]

For some runs with small propellers, especially where they do not hit ~70% of max RPM, it would be good to test to remove the last reductor stage, for more torque & less friction

[@eddraouyayman]

greate video bro!👍👍

[@DrEngine]

Thanks! 👍

[@PaulStephenDelosSantos]

0:07 I like the sound at speed 2×! Cool noise!

[@epiczails8441]

Putting in the propellers it just so satisfying

[@longsimpganyuu]

Man I love seeing propeller pieces when I was a child

[@rubythereptile]

love your channel

[@Alche987]

Maybe try to make a cilinder around some of them to funnel the wind?

[@DrEngine]

Nice suggestion!

[@IcheeCOTC]

I heard somewhere that propellers with more blades can apply more force per RPM but can't be spun as quickly. looking at the chart, the 2B9D and the 3B9D produce the same amount of wind, with the 3B9D being slightly slower. I think this is true, but there might be inefficiencies which causes the level to not coincide.

[@falkez1514]

bro had such a good first try that it took a redesign and 9 other tries to beat it lmao

[@Domus_Maximus]

It's a bit of a flawed test, not only because the ball will just let the air flow around it and/or leave the air current as it ascends. Perhaps try propeller designs on a vehicle on rails, then you can measure both the weight and speed the designs can move?

[@MIRGAN33]

Кто нибудь, откройте окно. Здесь слишком душно.

[@IstasPumaNevada]

I enjoyed this video, but I would also like if you performed the tests again with more scientific rigor, using some of the comment suggestions like testing all the blades flipped around too, aligning the fan direction with the incline, and testing different gearing for the fans to see which gearing works best for each one.

[@SmartLegoSG]

You're always so creative with your ideas. I'm always excited to see what you come up with next.

[@universalvastplays]

Lego x HotWheels x White Ball, never expected such a collab!

[@CatDaddyTuning]

There is a maximum power for the first half of the tests. A more effective prop takes more power so you end up with nothing but the 2 blade getting past 5 until the ducted fans.

[@Blank-n7c]

Great propeller invention

[@Pinkiewithmint101]

That one Propeller just ripped apart

[@JjMn1000]

I noticed(as some others have also stated) that some of the propellers seemed to have been spun backwards

[@sop1918]

There’s official Leto rotor pieces, many from Lego city helicopters, would be cool to see them

[@ЛидияПопова-ч7и]

Great video! However, like all your previous ones👍🔥

[@DrEngine]

Glad you like them!

[@francim.5480]

The 2 Blade is always the best, for air or water

[@MatematicaTel]

That´s amazing!! Greetings from Brasil!

[@PaulStephenDelosSantos]

4:51 It broke but it still did it😂😂😂😮😮😮 The ball was like levitating

[@elisamarzilli1463]

Gg

[@yeetboil9172]

I like the idea but you really should’ve made a stronger structure for the big heavy propellers and held them down to use them most effectively

[@GeneralML]

Wouldn't it make sense to tilt the propellor in line to the desired direction of travel of the ball? You might have a propellor capable of lifting the ball vertically, but if you put the rail perpendicular, the ball won't move...

[@RCmies]

now make a flying plane built out of lego using this knowledge... It's probably impossible but with enough wing span and really light build, maybe the body just made out of cross axle rods and some fabric or vinyl for wings, and using a small non-lego motor with small battery it could be possible. Or maybe a rubber band plane? Would be cool Lego achievement nonetheless.

[@MrBenski81]

Many of the props you have running in reverse. Take note of the aerofoil. The rounded edge leads the way. NOT the sharp edge. Had you used a snail scroll blower, you'd have sent that ping pong ball vertical.

[@swezyys]

Amazing ❤❤

[@DrEngine]

Thank you! Cheers!

[@sulaimanabdullah952]

I found this video very interesting. Thanks You might want to try one (or more) of your propellers with a single motor and different gear ratios. There will be a 'sweet spot' where 'matching' the propeller to the motor is best. Just a thought

[@DrEngine]

Thanks for the tips!

[@ctrlaltdel02]

If RPM's drops from maximum and wind speed stays almost same going to different propeller, than it tels you, you have not enought power. First few tests is not valid due to motor not being powerfull enought to drive all attached propellers at 11k rpm's. At that point you are not testing propellers, but motor.

[@SWellWellWell]

or shows the influence of the propeller on the engine ;)

[@oldhorn420]

He needs to use a brushless motor or put more motors

[@woaminibricks]

The truth is that having many blades does not mean the wind will be strong

[@佐々木広和-g3h]

今学校で歯車使った学習してるからこのすごさがすごくわかる😊

[@lastultimateultima]

i NEED to get those 14L blades, will help a lot in this summer

[@lastultimateultima]

nvm prob unavailable

[@danielhpcx]

Amazing video ❤ Part 2 with counter rotating blades

[@DrEngine]

Noted!

[@MikaelLevoniemi]

I think a small propeller might've done it too if it had a cowl around it.

[@flohwald]

8:19 Why don't the levels fit with the wind speeds?

[@Desasteroid]

I feel like the rotational speed and generated windspeeds aren't as much of a factor if the fan isn't large enough to direct its wind at the ball anymore, no? That's why most of the fans top out at Level 5.

[@DrEngine]

You're right! That’s why fans often have a top speed-they reach a point where more power doesn't enhance the airflow in a meaningful way.

[@nerokashitaro1181]

Have you tried combining solar panel with Lego?😎👍

[@Tails-wu3cx]

Can you do a tutorial or show how to connect your Lego engine to your volt thing

[@UpgradedTitans01]

What is that white lego part that likes lego?

[@arvidklangagerup7c319]

The first level five edged me so bad bro

[@Casphea]

adding more blades increases the drag

[@joaogabrielgamer1461]

4:22 cheating

[@DecayedPage]

Wouldnt the Propeller 3 Blade 13 Diameter work better flipped around? Im just judging by the shape of the blades. Wouldnt it also be able to take in more air because of the curve?

[@victoriannordmann4333]

Most ships used three blades, because the drag lower the rpm and use more fuel

[@christopherdeleon-r5n]

The lego one is like a sounds like helicopter propeller broking

[@AaronTureRonAbrahamsson157]

Wow! You’re doing great work and I hope you are able to best! 😊

[@DrEngine]

Thank you so much!

[@Roboseal2]

I know this might be extremely hard to do but what if you tried Contra-rotating props? The Antonov an70 has them

[@aFrInaTiOn]

Nahw, you forgot to turn the white rotor blades by 90° - it will push much more are (and also creating much more resistance :D) Besides that little miss it isnice content, thanks ♥

[@DrEngine]

Thanks for the tip!

[@baitsforyou]

my fyp be like! he woill watch anything

[@PaulStephenDelosSantos]

3:22 The ball was flying ✈️✈️✈️

[@eno88]

6:42 turning OSHA into OSHI-

[@Dzerenon]

add a chamber so air won't run away out the propeller. would work the best with WW/saw and propeller 1 blade with two pin holes x3 and x6

[@DrEngine]

Thanks for the tip

[@Morjensful]

The more complicated propellers cause more turbulence than airflow

[@Infinitelucidmaze]

You should have angled the fans with the ramp

[@LucasOliveira-dm8mb]

Algumas helices foram montadas ao contrario. Helice tem lado e isso influencia drasticamente no resultado. O lado da pá que é convexo deve ficar virado pra onde entra o ar na hélice, o lado concavo deve ficar virado pra onde o ar sai.

[@minhkhangnguyen932]

2:14 that use for water

[@minhkhangnguyen932]

7:56 bro make an whole tornado

[@Blockenheimer]

1:01 One must imagine Sisyphus happy

[@kristianstaalby8499]

Planetary gearbox/gearset when?

[@matheusandrade1260]

Why didn't you use counter-rotating propellers?

[@SWellWellWell]

Is the Model "WW" model a "Water Wheel" ?

[@RandomDudeRoblox]

6:10 bro just want to move near the ball 💀

[@yeetboy88YT]

i feel like it was not a good test because of how the wind would blow the more focused the stream of air the better it would be

[@ryanjulius9037]

How does that work?

[@Retrobricks]

good video, thanks for sharing

[@willslifewithoutschool]

What camera are you using?

[@S3176959]

6:12 you almost had a Centrifugal here, just needed to block off the Backplate and add a Case.

[@patrickbarna4546]

looks like size really does matter

[@kevtheoggamer6672]

For some reason the white ones seem to work best

[@Yarek653]

can you do a drone next??

[@Slap.kakish123-slapbattles]

4:14 here we needed a wedge-shaped plug like an airplane so that all the air would shift to one point

[@Godzilla20191]

The wheel was beating up the track

[@LizzethAlvarado-et4bf]

The final one its like neptune's winds

[@SWellWellWell]

Increasing the number of blades does not always lead to better results... 🤔

[@theconsoleinthecloset]

7:16 I like the 3 bladed fan blades, Sounds like a air conditioner, Build one

[@noamharduf]

i am a big fan of your woke kip it up😁

[@ilovebricksz]

Nice!

[@0.3113]

4:20 - Screw it

[@LegoBoomSG]

good video :33

[@DrEngine]

Thanks for watching

[@countchompula1896]

2 of those are boat propellers, not aircraft.

[@VilémŠťastný]

what about cooling pad ? its good idea or bad idea I need something to cool down my pc :D

[@jasonrogers1576]

What do you mean "6 diameter"? 6 what?

[@sophiavasqueznguyen1039]

The blades of the propellers diameter

[@logansavoy4708]

Six studs

[@FrankieAmadeian.]

Six kroingles, obviously. I'm able to measure it with my flebglom

[@cinimatics]

6 diameters. Obviously.

[@brunorleite]

Units

[@PaulStephenDelosSantos]

3:50 I thought the wind could be stronger but when it was level three it already failed 😭😭😭