That worked pretty much how I expected it would. Maybe even better lol. It was lots of fun though and I’m glad I could participate! Some of the more complex designing I’ve done in a while. Hopefully I didn’t damage your ears too bad!
i loved it! the biggest change i’d make is some bearings for the gear shafts, it’s a super fun design, though! i was thinking during the video that that and staggered-height fans might allow for longer blades and smoother movement.
The little fans need a shroud. I think not having it made the air disperse a lot. Also could some blades(2~4) be added to the main gear? Just not as big as a normal fan. Half of the space being used by those blades and half by the gears. There are many ways to approach this design haha
I love how the smoke was even like, "no way am I getting close to that loud fan." Those back swept blades on the falchion seemed to make quite smooth airflow. Not sure if it is the fences or the blade direction not funneling all the air towards the middle like a forward swept blade. I always forget if you are using the stock a12x25 fan or the 3D printed fan for the standings. If the injection molded, smoothed, production quality one, then I think you should change it out for a 3D printed version just to keep finish quality from affecting standings.
I also would like to see how it translates into cooling performance. Center moving air vs uniform flow. Although i guess the straightener on the cheater showed it improves it. I also would like to see 3d printed noctua and t33 as reference on the board.
He did an episode a while back discussing surface finish. It has no measurable effect outside the margin of error. Weight of the blade would matter though.
Highly recommend looking into a fdm style printer in addition to a resin printer (something like an ender 3 v2, ender 3 s1, or ender 2 pro might be worth taking a look at for a first fdm printer)
@@3CODKing fused deposition modeling - the kind of printer like the ender 3 that melts plastic filament and deposits it layer by layer, as apposed to the resin printers like Daniels Anycubic Mono that uses resin in a bath and uses UV light to set the plastic.
I'm most impressed with the missing blade fan; it still pushes reasonable air, is not crazy loud, and is shockingly well balanced given its wonky appearance. Great job Marnix!
Always a good day when a new Fan Showdown episode comes out and I'm already looking forward to the next! Two quick notes for anyone designing a gear fan based on my research and experience designing the contra (+the update I'm working on) First the distance I used from the top of the motor to the underside of the frame was 2.5mm based on the prior video this seem to be a good ball park figure to keep in mine to avoid parts rubbing. Second, gears with smaller teeth at a higher tooth count should produce less noise. For the contra I played it safe with straight cut gears and a module of 1 but in some recent test prints I've gotten gears with a 30 degree helix and a module of 0.5 to print beautifully on a 0.4 print head so getting noise down to a "reasonable" level might be achievable
Spur gears are inherently noisy which is why older gear boxes in cars & trucks make a lot of noise and why vehicle makers moved to helical cut gears in the late 50s early 60s. Many still left 1st, 2nd and reverse as spur cut and this is evident when cars/trucks of this vintage move off or back up. Parson's turbine put into a Royal Navy ship used Helical cut gears for this reason. The noise would have been unbearable plus Helical cut distribute load better across the teeth reducing gear stripping. Effectively two teeth are engaged at once whereas a spur cut gear hops from one tooth to the next. As you note, smaller teeth make less noise simply because the 'hop' is smaller. More precision can help too.
The Spinning Duct kinda looks like a restaurant's Hood Exhaust Fan system. What if we made one as a case fan, since they obviously do a great job at getting air out of an area?
the spinny duct fan makes me wonder how well a cone shaped fan would work, with the small end of the cone being the intake. it seems to be throwing a good deal of air back out and i think it must be because of the angled part at the blades acting with centrifugal force.
Two things: the missing blade fan sounds amazing (from the perspective of a musician (who doesn't have to listen to it all day long)). And the duplicator is amazing - it looks like a special effect entry into the fan showdown. Maybe not optimal performance, but that airflow is wild.
Spinny Duct, like the last iteration of that idea, keeps trying to act as a centrifugal pump. Perhaps time to abandon that idea. Missing Blade sounds like a variant of the uneven spaced blade idea for noise reduction. The Falchion is rather quiet given that anyone who owns an EVGA 10 series GPU could tell you about how loud the back swept fan blade design on them can get! Duplicator gets no comment from me other than that it makes my teeth itch how loud it is for so little airflow.
Or you could reverse the blades on the Spinny Duct so the blades push the air in the same direction as the centrifugal forces. But even then I feel the spinning duct idea isn't that promising. To high a load on the bearings in the fan motor is just part of the problem. The design could however probably be adapted to be used as the cone part of the Cheater. It would be interesting to see three different configurations for this. Just the cone, the cone with the blades as they currently are and the cone with the blades reversed. With the blades retained in the cone they would act as a stator for the actual fan. However usually the stator is placed on the outlet side of the fan. So it would be interesting to see if adding a stator on the intake improves or decrease the performance and is so what it does for the noise. Edit: Yes the missing blade fan changes the frequency spectrum for the noise, and that's why some fans has had uneven blade geometry. Instead of one sharp spike in the frequency graph the noise is supposedly spread out over a wider spectrum, but with less energy in any one frequency that what you get with evenly spaced fan blades. And the frequency graph seems to support this.
@@martindinner3621 De Laval nozzles are exclusively for supersonic flow or pressures exceeding a few entire atmospheres of pressure. If your fan setup is generating supersonic flows or massive pressures, something absolutely bugfuck insane is going on and you need to show it to Pratt and Whitney or Aerojet Rocketdyne.
The Duplicator gear fan is way, way louder than the air compressor in my shop! I don't think I have time to work on it, but for me it would be super interesting to design the quietest fan possible that still moves air well (like about as well as the reference fan).
the missing fan blade method is a method currently employed by many automakers, and was used as early as the 1950's on radiator fans to change the audio profile to something less annoying and choppy. it actually works, and moves just as much air as if the fan blade was there.
I really want to see some of the top fans pitted against THEMSELVES, traditionally printed vs resin printed. It'd be super cool to see how a smoother surface changes performance
Few suggestions to the duplicator: I think if you added some thin clacking strips and a striker, add the smoke machine and turned the fan to a random pulse you have yourself an automatic New Years Cela-tron 2000 lol.
I'm no physicist but the "spinny thingy" appears to work against itself as the centrifugal energy is forced backwards in the cone/duct. It would be interesting to see the inverse of the cone where it used the CF to assist in moving the air through the fan by creating more of a vacuum aft making the air to "want" to flow through duct faster. Just some thoughts. Awaiting patiently.
I feel like the fan gears should be helical due to them having less resistance and being quieter. It's worth a test. Edit: also some small electronics gear oil would be great for sound reduction.
The Duplicator's gears need to be MUCH finer. It need about 3 to 4 times the current teeth number. Then, making them chevron type will also help reducing the noise level.
Wow, the Duplicator looked pretty funny! I knew it wouldn't perform well but it is still quite entertaining to see these funny, overengineered shapes, especially the geared ones, working at least a little!
Thanks for printing my fan! I designed the spiny duct and seeing the test results and reading the comments gave me some great ideas. I redesigned it to have a smaller inlet and larger outlet. Also reduced the weight by almost 80% so it should spin much faster. Hoping V2 performs much better than V1.
this video is exactly what i love about "crowdsourced" solutions over stuff generated by people at mit. i came to this channel for the 3d printing, stayed for the fan fan competitions (who knew id be interested in such a thing?) and im learning about lateral airmass movement during an aircraft stall.
5:45 I enjoy that your reaction to "I need this part to be very slightly higher" is "let's 3d print 1/8th of this model and use it as spacers" instead of, y'know, finding a couple of washers.
The spiny duct isn't a Velocity Stack, at least not as designed there. A velocity stack has a few distinct features, namely, the leading surface is curved to act like an airfoil and accelerate air into the mouth (via high/low pressure differences), and also has a progressive taper to the inlet. Pretty sure the straight sides in this design was one contributing factor in the air not wanting to enter (another reason, as someone else mentioned, could be Magnus Effect... although that might the proper name for what I was pointing out? haha 😊😅)
if that spinning duct fan had impeller pegs at the angle shift point, it would kick off that airflow adhering to the sides of the outside of the duct, just something i learned from another UA-camr, airflow will stick to surfaces and with the taper going backwards, it's effectively flowing air backwards on the outside of the duct.
Wow, 2 impressive fans for sure! I love seeing what people can come up with. I just wonder what would happen if the blades were extended to the end of the SpinnyDuct, but have the fan blades taper off the closer they get to the edge of the duct. And man, the Duplicator! While it didn't set any records at all, it is still very impressive! I'm just curious if it's because the fan blades all spin the same way. The trick would be to figure out how to get every other fan hub to spin the opposite way, similarly to how some of the GPU's have one set of fins and hub setup to spin the opposite direction. That in itself may be a feat for someone to take on. I don't care if it finished last, I don't care if it was loud. It put a smile on my face, and I'm glad you do the smoke test, because I was wondering what the air flow looked like. I've said it before, and I'll say it again, Keep up the great work! I do enjoy the weekly uploads, and I always look forward to them. Cheers!
The Spinny duct being tapered has centripetal forces working against it and pushing air out the front starving the blades, if anything the taper should be the opposite, narrower the further out that would accelerate the air to the blades.
Should've made the center gear a helical gear so it also moves a little bit of air. Wouldn't have made a huge difference but it would probably be worth something.
I was thinking that too, but then the smaller gears would have to turn the other way, possibly nullifying any benefit of the helical gear. However, helical gears might make it quieter.
I wish I could thumb up this episode TWICE :D I'm watching the Fan Showdown from its beginning, and I'm still surprised how creative are the submitters!
I hope next season your able to add some sort of back pressure for realistic fan testing some fans I would perform better some shall perform worse when a radiator or heat sync is added. Thanks for the continued enjoyment
The missing fan blade thing has been around for a long time actually... EMD locomotive group started doing that to their roof cooling fans back in the 60's to cut down on the roar they'd make while at full throttle and the cooling fans were maxed out. It actually works.
Random fun fact. if you get a light meter, there is a theater trick where if you get just the right amount of fog, everything looks like it's underwater. I only mention this because you play with fog enough, you could just do your closings "underwater" occasionally for giggles
Been watching this challenge long enough to see that some designs are getting seriously good. And some are seriously weird! :-) It would be interesting to see if any fan makers are watching this series and taking notes.
I don’t know if you’ve perhaps mentioned this at some point in the series but I figured it was worth noting. Noise is energy. So therefore the noise level of a fan can, not always of course but in a majority of cases, indicate the level of efficiency. At least in the cases above 55 db. Most of the time that extra noise is lost energy.
We have watched and analyzed every moment of this show, been here from the beginning, and taken everything we have learned and combined it into "The Monstrosity". We are around 20 hours into designing and testing. We believe it is nearing optimization and we will submit it soon.
Some cars use a fan blade set-up somewhat like the "missing blade" for their radiator fans, with the blades unevenly spaced but balanced. This setup results in a less harmonized or droning sound which is more pleasant over long duration (at least to the test audiences).
The like 1000 blade fan will spin, but suck because like half of each blade is directly over the motor meaning any air pulled to that area will get pushed sideways and make a bunch of dirty air that the fan itself cant grab so drop the efficiency to like poopoo. Thats my guess.
#suggestion 1) it seems for most designs (but not crazy ones...) you can try to check same cooler with different amount of blades. It is quite interesting how blades impact on the overall performance. 2) also you need another top list for cases 3) consider adding more top lists by most important factors
The unusual sound quality of the MFBBSB is what's termed "octave reinforcement" in acoustics. Because the gap between the heavy blade pair is twice that of the gap between all other pairs, the frequency of sound it generates is a whole octave lower. Although it's a much weaker wave than the wave an octave up, the higher frequency supports the lower one, and assists our ears in picking it out, so you end up with an overall effect that your ear is *receiving* sound that is very similar to most fans, but is *perceiving* a much lower tone. To my ear, this also makes the fact that there is any tuned pitch at all much more obvious.
The large ducted fan is a cool idea, but more mass equals more slowerer. But really, the friction from the ring moving seems ot throw the air away not help draw it in, ideally we want to turn that Kinetic energy of the fan to velocity in the through the fan direction not so much radial velocity. Other cool thing i learned: The fans can add velocity, pressure, and head. You can have all three or any one, but thats what fans and pumps do.
The effect of centrifugal force is so often overlooked. If the blade in The Spinning Duct were canted the other way it would probably do an amazing job at blowing the air the other way.
I had high hopes for the spinny duct, I think the creator is on the right track for success by integrating a shroud and fan together. It just needs the blades reworked.
Maybe it needs blades all the way out, to counteract the centrifuge effect. And an actual flare at the opening, since that's what makes air able to flow around the edge smoothly.
I'm loving these multi part fans!! It made me think of a ridiculous fan. The ifbiaac (inefficient fan because its actually a clock). Take the rpms of a fan and gear reduce it so many times that you could have a working wall clock. It would be the loudest thing in the world, and take 1000x more power than a regular clock, yet it seems fitting for this show.
This episode has got to be the most creative since I started watching regularly which may not have been at the very beginning, but pretty early. I've got to commend all the folks who spend their time and energy sitting with CAD programs to further this venture which is unique in the history of mankind's experiences in community. Go nerd power! Edit: could someone make a quieter fan for my Hartke bass amp? While the cluster of fan pitches is certainly drowned out when up to 500 watts of Thumpa Wumper get to Thumpa Wumping, when listening to music while learning, or just sitting quiet, the fan noise seriously clashes with the musical process. Thanks. 70mm, email in my About.
I think we could push the duplicator concept further, split the sungear into two layers; with the first one being the regular spur gear and the bottom one being a fan of its own
Spinny Duct is a great experiment. I believe that there are quite a few factors going against this fan in particular. 1.) The motor must rotate the entire mass of the duct and the fans. More mass == more energy (heat/current) == less RPM. Please verify Major Hardware? 2.) The interior surface area of the rotating duct ensures this fan lives up to it's name. It merely spins the air in the "tube". 3.) The conical air guide forces air back outward due to centrifugal forces. 4.) The pitch angle of the fins is far too aggressive for the RPM of this particular motor. Fantastic shape and flow though (without the duct)!! 5.) Balance is off. This is inherent with any 3D printed fan and not usually a major factor. The duct here develops a significant oscillation which leads to a destructive harmonic in the material. These harmonics across what looks like a 4 inch/100mm duct further impedes ingress airflow. Like multiple people on a trampoline randomly going in and out of sync. Fixing this balance issue is moot given point #2. I think there's room to grow here with both gears and EDM style designs. I.E. Electric turbo chargers. Temps too high? Arduino, temp sensor, solenoid, clutch, deafening noise == cooled PC, with proper sized cowbell. Given the rough texture of these prints, I wonder if there is a filament material that could withstand a super thin gel coat. A smooth surface would really go a long way to reduce turbulence.
This fan shodown reminded me of a car racing game I played with my brother long ago. We were racing on ice and the cars stuck to the road very well. He told me it was just like driving a car on ice, but that's not what I thought. He thought about it for a moment and said the cars have ice tires on them. So we went into the settings and put regular street tires on them... it was pretty much the disaster we thought it would be. So we quit playing after a few minutes. What happened next was the game system with its artificially intelligent drivers started the track with this same settings. It was so funny to watch and I was laughing so hard I couldn't get to the controller to shut it off. Thought I was going to die laughing. Think it took me 5 minutes to make the three feet to the controller. I had never before been crippled with such laughter. That geared fan is so absolutely amusing. Reminded me of almost dying laughing. Or at least that's how I felt at the time
How do you know so much about air force stuff and planes and flight and whatnot?? Im impressed, and love learning interested tid bits when i watch!! 👍🏻👍🏻
Interesting. Each mini fan had that classic tornado like intake with more testing and getting them to not interfere with each other this could be an interesting design
My hypothesis why Spinning Duct is not doing well as Cheater is Magnus effect deflecting the air. While the cone on Cheater is stationary, the cone on Spinning Duct is spinning with the fan creating Magnus effect in the process.
I challenge the designer of that gear fan to design a new one with overlapping mini-fans. My hypothesis is that with a bit of overlap, and thus the mini-fans being bigger, it could actually move a much bigger amount of air. Basically, there could be a way to make the spun area larger than the total area of the 120mm fan. The center hub would be of a smaller size as well, helping with the fan's performance.
Funny to see that duct fan blowing air both directions. The duplicator just throws it every direction. Then the others were both pretty comparable and effective. It's interesting seeing some wing design thrown into the mix with that falchion. Definitely seemed to give it a boost, being close to the same feet per minute with less rpm and a little more noise.
That worked pretty much how I expected it would. Maybe even better lol.
It was lots of fun though and I’m glad I could participate! Some of the more complex designing I’ve done in a while.
Hopefully I didn’t damage your ears too bad!
The Duplicator needs gap filling bearings
Hoppees
i loved it! the biggest change i’d make is some bearings for the gear shafts, it’s a super fun design, though! i was thinking during the video that that and staggered-height fans might allow for longer blades and smoother movement.
What about helical cut gears, instead of straight cuts?
The little fans need a shroud. I think not having it made the air disperse a lot.
Also could some blades(2~4) be added to the main gear? Just not as big as a normal fan. Half of the space being used by those blades and half by the gears.
There are many ways to approach this design haha
It just needs more oil to make it quieter. About a gallon in a bucket would do. Great fun fan.
I love how this series went from who can make the best fan to who can make a fan
I guess you could say we’re all fans.. sorry lol
not just make the fan but reinvent the fan entirely
Something almost entirely unlike a fan
Not a fan the COOLEST fan
Get it because fans cool stuff😂😂😂😂
9:30 the Spinning Duct is labeled "Duplicator", just to quell any potential confusion
Happens quite often too
one could say he... duplicated that name.
I love how the smoke was even like, "no way am I getting close to that loud fan."
Those back swept blades on the falchion seemed to make quite smooth airflow. Not sure if it is the fences or the blade direction not funneling all the air towards the middle like a forward swept blade.
I always forget if you are using the stock a12x25 fan or the 3D printed fan for the standings. If the injection molded, smoothed, production quality one, then I think you should change it out for a 3D printed version just to keep finish quality from affecting standings.
I also would like to see how it translates into cooling performance. Center moving air vs uniform flow. Although i guess the straightener on the cheater showed it improves it. I also would like to see 3d printed noctua and t33 as reference on the board.
He did an episode a while back discussing surface finish. It has no measurable effect outside the margin of error.
Weight of the blade would matter though.
iirc He did do a 3d printed a12x25 and it had almost no performance difference.
Quite confident that the fences are the main reason the falchion doesn't act as a centrifugal blower.
Even the "bad flow" fans are super gimmicky and really fun to see, with the craziest ideas.
I'm loving this series
I got into 3D printing because of this show. Got my first printer a month ago, an Anycubic Mono X, and I'm loving the 3D print life.
Highly recommend looking into a fdm style printer in addition to a resin printer (something like an ender 3 v2, ender 3 s1, or ender 2 pro might be worth taking a look at for a first fdm printer)
Amazing choice I have the same printer and I love it!
I was waiting on money, but now I have practice at least.
@@zzace00 sorry, fdm style?
@@3CODKing fused deposition modeling - the kind of printer like the ender 3 that melts plastic filament and deposits it layer by layer, as apposed to the resin printers like Daniels Anycubic Mono that uses resin in a bath and uses UV light to set the plastic.
I'm most impressed with the missing blade fan; it still pushes reasonable air, is not crazy loud, and is shockingly well balanced given its wonky appearance. Great job Marnix!
Thats the power of calculus. I'm assuming they used calculus, I would hate to try to solve that problem with trial and error.
I love that the duplicator is above the NIOSH recommended exposure limit for noise.
I kinda love the sound of the missing blade, sounds like a prop plane
"What way is the spinning duct fan blowing?"
Spinning duct fan: "Yes."
Super happy with how my fan performed! And great explanation of the function of the fences on airplane wings!
i'd like to see a leaderboard according to sound, or maybe have a cfm per db ratio
yeah, that would be a nice addition!
yes cfm per db is the best way imo, but also perceived loudness through tones is just as important
Always a good day when a new Fan Showdown episode comes out and I'm already looking forward to the next!
Two quick notes for anyone designing a gear fan based on my research and experience designing the contra (+the update I'm working on)
First the distance I used from the top of the motor to the underside of the frame was 2.5mm based on the prior video this seem to be a good ball park figure to keep in mine to avoid parts rubbing.
Second, gears with smaller teeth at a higher tooth count should produce less noise. For the contra I played it safe with straight cut gears and a module of 1 but in some recent test prints I've gotten gears with a 30 degree helix and a module of 0.5 to print beautifully on a 0.4 print head so getting noise down to a "reasonable" level might be achievable
Spur gears are inherently noisy which is why older gear boxes in cars & trucks make a lot of noise and why vehicle makers moved to helical cut gears in the late 50s early 60s. Many still left 1st, 2nd and reverse as spur cut and this is evident when cars/trucks of this vintage move off or back up.
Parson's turbine put into a Royal Navy ship used Helical cut gears for this reason. The noise would have been unbearable plus Helical cut distribute load better across the teeth reducing gear stripping. Effectively two teeth are engaged at once whereas a spur cut gear hops from one tooth to the next. As you note, smaller teeth make less noise simply because the 'hop' is smaller. More precision can help too.
The Spinning Duct kinda looks like a restaurant's Hood Exhaust Fan system. What if we made one as a case fan, since they obviously do a great job at getting air out of an area?
the spinny duct fan makes me wonder how well a cone shaped fan would work, with the small end of the cone being the intake. it seems to be throwing a good deal of air back out and i think it must be because of the angled part at the blades acting with centrifugal force.
A nozzle of sorts could work
Yes, seems to me he rotated it the wrong way-
Definitely seems it needs to be reversed. Look at how a rocket nozzle is designed for Instance. I bet it would perform decently well.
Exactly, Spin the other way and it will perform much better.
Two things: the missing blade fan sounds amazing (from the perspective of a musician (who doesn't have to listen to it all day long)). And the duplicator is amazing - it looks like a special effect entry into the fan showdown. Maybe not optimal performance, but that airflow is wild.
These clockpunk fans are cool even if not really practical.
Spinny Duct, like the last iteration of that idea, keeps trying to act as a centrifugal pump. Perhaps time to abandon that idea. Missing Blade sounds like a variant of the uneven spaced blade idea for noise reduction. The Falchion is rather quiet given that anyone who owns an EVGA 10 series GPU could tell you about how loud the back swept fan blade design on them can get!
Duplicator gets no comment from me other than that it makes my teeth itch how loud it is for so little airflow.
lean all the way into that and go for the housed fan arrangement.
@@Cynyr That's essentially The Cheater.
@@EinhanderSn0m4n okay, so take the Cheater one step farther and apply deLaval nozzle principals to it.
Or you could reverse the blades on the Spinny Duct so the blades push the air in the same direction as the centrifugal forces. But even then I feel the spinning duct idea isn't that promising. To high a load on the bearings in the fan motor is just part of the problem.
The design could however probably be adapted to be used as the cone part of the Cheater. It would be interesting to see three different configurations for this. Just the cone, the cone with the blades as they currently are and the cone with the blades reversed. With the blades retained in the cone they would act as a stator for the actual fan. However usually the stator is placed on the outlet side of the fan. So it would be interesting to see if adding a stator on the intake improves or decrease the performance and is so what it does for the noise.
Edit: Yes the missing blade fan changes the frequency spectrum for the noise, and that's why some fans has had uneven blade geometry. Instead of one sharp spike in the frequency graph the noise is supposedly spread out over a wider spectrum, but with less energy in any one frequency that what you get with evenly spaced fan blades. And the frequency graph seems to support this.
@@martindinner3621 De Laval nozzles are exclusively for supersonic flow or pressures exceeding a few entire atmospheres of pressure. If your fan setup is generating supersonic flows or massive pressures, something absolutely bugfuck insane is going on and you need to show it to Pratt and Whitney or Aerojet Rocketdyne.
The Duplicator gear fan is way, way louder than the air compressor in my shop! I don't think I have time to work on it, but for me it would be super interesting to design the quietest fan possible that still moves air well (like about as well as the reference fan).
the missing fan blade method is a method currently employed by many automakers, and was used as early as the 1950's on radiator fans to change the audio profile to something less annoying and choppy. it actually works, and moves just as much air as if the fan blade was there.
Ah yes! This is indeed true! I remembered again thanks to you
Pretty sure another fan did a similar thing. Maybe in season 1.
I really want to see some of the top fans pitted against THEMSELVES, traditionally printed vs resin printed. It'd be super cool to see how a smoother surface changes performance
You should release a supercut of every smoke test to use as a visualizer while listening to music and working!
Few suggestions to the duplicator: I think if you added some thin clacking strips and a striker, add the smoke machine and turned the fan to a random pulse you have yourself an automatic New Years Cela-tron 2000 lol.
I'm no physicist but the "spinny thingy" appears to work against itself as the centrifugal energy is forced backwards in the cone/duct. It would be interesting to see the inverse of the cone where it used the CF to assist in moving the air through the fan by creating more of a vacuum aft making the air to "want" to flow through duct faster. Just some thoughts. Awaiting patiently.
I feel like the fan gears should be helical due to them having less resistance and being quieter. It's worth a test.
Edit: also some small electronics gear oil would be great for sound reduction.
the filament is less of a yellow and more of a Shrek green. I love it!
The Duplicator's gears need to be MUCH finer. It need about 3 to 4 times the current teeth number. Then, making them chevron type will also help reducing the noise level.
Would also help to have a second brace on the rear of the frame to better stabilize the gears against the hub.
Woah, it's been a season since I've watched an episode. Your tests have gotten much more sophisticated. That's great.
Wow, the Duplicator looked pretty funny! I knew it wouldn't perform well but it is still quite entertaining to see these funny, overengineered shapes, especially the geared ones, working at least a little!
Thanks for printing my fan! I designed the spiny duct and seeing the test results and reading the comments gave me some great ideas. I redesigned it to have a smaller inlet and larger outlet. Also reduced the weight by almost 80% so it should spin much faster. Hoping V2 performs much better than V1.
7:06 Do it in a diagonal order, to make it more balanced. Same thing is done on car wheels.
this video is exactly what i love about "crowdsourced" solutions over stuff generated by people at mit. i came to this channel for the 3d printing, stayed for the fan fan competitions (who knew id be interested in such a thing?) and im learning about lateral airmass movement during an aircraft stall.
First time on your channel, but I LOVE the use of the fog machine to test the air flow! Very creative!
I wonder if the spinny duct was so turbulent because it was producing magnus effect?
Not just its spinning. You could see it slapping air back out the mouth with how much it wobbled.
id maybe put spinny ducts on the duplicator's mini fans to stop it acting like a centrifugal pump and forcing air into the middle
I love seeing the progression in the quality of your videos, and all the little things you constantly refine or try out big props 👍👍
5:45 I enjoy that your reaction to "I need this part to be very slightly higher" is "let's 3d print 1/8th of this model and use it as spacers" instead of, y'know, finding a couple of washers.
The spiny duct isn't a Velocity Stack, at least not as designed there. A velocity stack has a few distinct features, namely, the leading surface is curved to act like an airfoil and accelerate air into the mouth (via high/low pressure differences), and also has a progressive taper to the inlet.
Pretty sure the straight sides in this design was one contributing factor in the air not wanting to enter (another reason, as someone else mentioned, could be Magnus Effect... although that might the proper name for what I was pointing out? haha 😊😅)
if that spinning duct fan had impeller pegs at the angle shift point, it would kick off that airflow adhering to the sides of the outside of the duct, just something i learned from another UA-camr, airflow will stick to surfaces and with the taper going backwards, it's effectively flowing air backwards on the outside of the duct.
This series has come so far, just amazing
I absolutely love what you're doing with this show, keep up the amazing work!
I bet the Spinny Duct would do pretty well if mirrored or run in reverse....
As a man who thinks about aeronautical engineering almost constantly, I think this just became my new favorite channel! Thank you for these videos!
Wow, 2 impressive fans for sure! I love seeing what people can come up with. I just wonder what would happen if the blades were extended to the end of the SpinnyDuct, but have the fan blades taper off the closer they get to the edge of the duct. And man, the Duplicator! While it didn't set any records at all, it is still very impressive! I'm just curious if it's because the fan blades all spin the same way. The trick would be to figure out how to get every other fan hub to spin the opposite way, similarly to how some of the GPU's have one set of fins and hub setup to spin the opposite direction. That in itself may be a feat for someone to take on. I don't care if it finished last, I don't care if it was loud. It put a smile on my face, and I'm glad you do the smoke test, because I was wondering what the air flow looked like.
I've said it before, and I'll say it again, Keep up the great work! I do enjoy the weekly uploads, and I always look forward to them.
Cheers!
It's amazing to see where your channel started and where it is now. You and the participants are truly mad scientists. For science!
The creativity of this community never ceases to amaze me.
I love how "ridiculousness" is a valid goal in what you've created here.
The Spinny duct being tapered has centripetal forces working against it and pushing air out the front starving the blades, if anything the taper should be the opposite, narrower the further out that would accelerate the air to the blades.
Should've made the center gear a helical gear so it also moves a little bit of air. Wouldn't have made a huge difference but it would probably be worth something.
I was thinking that too, but then the smaller gears would have to turn the other way, possibly nullifying any benefit of the helical gear.
However, helical gears might make it quieter.
or a harringbone gear
I wish I could thumb up this episode TWICE :D I'm watching the Fan Showdown from its beginning, and I'm still surprised how creative are the submitters!
I hope next season your able to add some sort of back pressure for realistic fan testing some fans I would perform better some shall perform worse when a radiator or heat sync is added.
Thanks for the continued enjoyment
You should increase fan size and stagger the height on the duplicator.
i thought the same thing, it's blades could be a lot bigger if there weren't six of them in the same layer.
Highest production fan showdown show on the dang UA-cams !!! Great episode man, thanks for all your hard work !
I like how the smoke is hesitant to approach the Duplicator like ‘bro wtf is that??’
Got to love the name change half way through the video the spiny duct turned into the duplicator during the smoke test
the ducted fan has a wobble the sound it makes is it hitting the frame of the fan rig, and that slow smoke on the geared fan was perfect
The missing fan blade thing has been around for a long time actually... EMD locomotive group started doing that to their roof cooling fans back in the 60's to cut down on the roar they'd make while at full throttle and the cooling fans were maxed out. It actually works.
Random fun fact. if you get a light meter, there is a theater trick where if you get just the right amount of fog, everything looks like it's underwater.
I only mention this because you play with fog enough, you could just do your closings "underwater" occasionally for giggles
Been watching this challenge long enough to see that some designs are getting seriously good. And some are seriously weird! :-) It would be interesting to see if any fan makers are watching this series and taking notes.
spinnyduct needs its blades reversed for it to work, alot of the smoke looked to be hitting the skirt and get flung back the way it came
I don’t know if you’ve perhaps mentioned this at some point in the series but I figured it was worth noting. Noise is energy. So therefore the noise level of a fan can, not always of course but in a majority of cases, indicate the level of efficiency. At least in the cases above 55 db. Most of the time that extra noise is lost energy.
I'd put that missing blade fan on my bedside table at nap time. Something about that sound was so very soothing.
That missing blade fan has a very relaxing sound.
We have watched and analyzed every moment of this show, been here from the beginning, and taken everything we have learned and combined it into "The Monstrosity". We are around 20 hours into designing and testing. We believe it is nearing optimization and we will submit it soon.
I love the random touch of Herb Albert in the intermission.
can we get like a 1 hr loop of the missing blade fan? that is some nice white noise to sleep to
Some cars use a fan blade set-up somewhat like the "missing blade" for their radiator fans, with the blades unevenly spaced but balanced. This setup results in a less harmonized or droning sound which is more pleasant over long duration (at least to the test audiences).
The like 1000 blade fan will spin, but suck because like half of each blade is directly over the motor meaning any air pulled to that area will get pushed sideways and make a bunch of dirty air that the fan itself cant grab so drop the efficiency to like poopoo. Thats my guess.
The Spinning Duct seems to create an internal vortex that plugs up the hole rather than assisting flow like a duct stack normally does.
Yo dawg, we heard you like fans so we put fans on your fans
Okay but the duplicator as dispersal mechanism is fantastic
#suggestion 1) it seems for most designs (but not crazy ones...) you can try to check same cooler with different amount of blades. It is quite interesting how blades impact on the overall performance. 2) also you need another top list for cases 3) consider adding more top lists by most important factors
That missing blade one sounded SO good that it actually makes be want to buy a PC just to hear it
The unusual sound quality of the MFBBSB is what's termed "octave reinforcement" in acoustics.
Because the gap between the heavy blade pair is twice that of the gap between all other pairs, the frequency of sound it generates is a whole octave lower. Although it's a much weaker wave than the wave an octave up, the higher frequency supports the lower one, and assists our ears in picking it out, so you end up with an overall effect that your ear is *receiving* sound that is very similar to most fans, but is *perceiving* a much lower tone.
To my ear, this also makes the fact that there is any tuned pitch at all much more obvious.
That crossplane growl of the missing blade fan. Nice..
The large ducted fan is a cool idea, but more mass equals more slowerer. But really, the friction from the ring moving seems ot throw the air away not help draw it in, ideally we want to turn that Kinetic energy of the fan to velocity in the through the fan direction not so much radial velocity. Other cool thing i learned: The fans can add velocity, pressure, and head. You can have all three or any one, but thats what fans and pumps do.
the wing fences don't prevent the wing from stalling all at once. They prevent the wing tip from stalling first, which would cause a violent roll.
The effect of centrifugal force is so often overlooked. If the blade in The Spinning Duct were canted the other way it would probably do an amazing job at blowing the air the other way.
I had high hopes for the spinny duct, I think the creator is on the right track for success by integrating a shroud and fan together. It just needs the blades reworked.
Maybe it needs blades all the way out, to counteract the centrifuge effect. And an actual flare at the opening, since that's what makes air able to flow around the edge smoothly.
I'm loving these multi part fans!! It made me think of a ridiculous fan. The ifbiaac (inefficient fan because its actually a clock). Take the rpms of a fan and gear reduce it so many times that you could have a working wall clock. It would be the loudest thing in the world, and take 1000x more power than a regular clock, yet it seems fitting for this show.
Some older truck engines included cooling fans with asymmetrical blade spacing to change the harmonics of the airflow noise
This episode has got to be the most creative since I started watching regularly which may not have been at the very beginning, but pretty early.
I've got to commend all the folks who spend their time and energy sitting with CAD programs to further this venture which is unique in the history of mankind's experiences in community.
Go nerd power!
Edit: could someone make a quieter fan for my Hartke bass amp?
While the cluster of fan pitches is certainly drowned out when up to 500 watts of Thumpa Wumper get to Thumpa Wumping, when listening to music while learning, or just sitting quiet, the fan noise seriously clashes with the musical process.
Thanks.
70mm, email in my About.
The stubby propellers on that noisy boi reminds me of the propellers on the XF-84 Thunderscreech, the loudest plane ever.
I think we could push the duplicator concept further, split the sungear into two layers; with the first one being the regular spur gear and the bottom one being a fan of its own
Spinny Duct is a great experiment. I believe that there are quite a few factors going against this fan in particular.
1.) The motor must rotate the entire mass of the duct and the fans. More mass == more energy (heat/current) == less RPM. Please verify Major Hardware?
2.) The interior surface area of the rotating duct ensures this fan lives up to it's name. It merely spins the air in the "tube".
3.) The conical air guide forces air back outward due to centrifugal forces.
4.) The pitch angle of the fins is far too aggressive for the RPM of this particular motor. Fantastic shape and flow though (without the duct)!!
5.) Balance is off. This is inherent with any 3D printed fan and not usually a major factor. The duct here develops a significant oscillation which leads to a destructive harmonic in the material. These harmonics across what looks like a 4 inch/100mm duct further impedes ingress airflow. Like multiple people on a trampoline randomly going in and out of sync. Fixing this balance issue is moot given point #2.
I think there's room to grow here with both gears and EDM style designs. I.E. Electric turbo chargers. Temps too high? Arduino, temp sensor, solenoid, clutch, deafening noise == cooled PC, with proper sized cowbell.
Given the rough texture of these prints, I wonder if there is a filament material that could withstand a super thin gel coat. A smooth surface would really go a long way to reduce turbulence.
I laughed out loud when the puff of smoke cringed away from The Duplicator with trepidation.
Perhaps the duplicator could be used as a dough mixer.
The spinning duct cone expands which means outward pressure shoots air forward instead of backward
The white noise sound from the missing blade 🤤😍
This fan shodown reminded me of a car racing game I played with my brother long ago. We were racing on ice and the cars stuck to the road very well. He told me it was just like driving a car on ice, but that's not what I thought. He thought about it for a moment and said the cars have ice tires on them. So we went into the settings and put regular street tires on them... it was pretty much the disaster we thought it would be. So we quit playing after a few minutes. What happened next was the game system with its artificially intelligent drivers started the track with this same settings. It was so funny to watch and I was laughing so hard I couldn't get to the controller to shut it off. Thought I was going to die laughing. Think it took me 5 minutes to make the three feet to the controller. I had never before been crippled with such laughter. That geared fan is so absolutely amusing. Reminded me of almost dying laughing. Or at least that's how I felt at the time
"The fan itself"? Noooo, the fan itself is the blades! You want to attach the auxiliary frame to the main fan FRAME.
How do you know so much about air force stuff and planes and flight and whatnot?? Im impressed, and love learning interested tid bits when i watch!! 👍🏻👍🏻
Interesting. Each mini fan had that classic tornado like intake with more testing and getting them to not interfere with each other this could be an interesting design
The smoke can't break through the noise barrier of the duplicator!
My hypothesis why Spinning Duct is not doing well as Cheater is Magnus effect deflecting the air. While the cone on Cheater is stationary, the cone on Spinning Duct is spinning with the fan creating Magnus effect in the process.
First fan I’ve seen ppl make with proper airfoil design.
We need an entire gear fan episode. gear fan vs gear fan!
I challenge the designer of that gear fan to design a new one with overlapping mini-fans. My hypothesis is that with a bit of overlap, and thus the mini-fans being bigger, it could actually move a much bigger amount of air. Basically, there could be a way to make the spun area larger than the total area of the 120mm fan. The center hub would be of a smaller size as well, helping with the fan's performance.
I like how he says we lost alot of f-100's to the saber dance but not the pilots.... lol
Funny to see that duct fan blowing air both directions. The duplicator just throws it every direction. Then the others were both pretty comparable and effective.
It's interesting seeing some wing design thrown into the mix with that falchion. Definitely seemed to give it a boost, being close to the same feet per minute with less rpm and a little more noise.