Not long after Dyson unveiled their “bladeless” fan, a fairly steady stream of ever cheaper clones have been hitting the market. But this 3D printed version created by [Elite Worm] must surely be one of the most budget-friendly takes on the concept. If you’ve got a 3D printer, we’d wager you’ve already got most of the parts required to build your own.
To be clear, of course there’s a blade. They aren’t magic, obviously. The fan is just small, and hidden inside the base. Air is pulled from the sides and bottom, and into the ring mounted to the top of the unit. When the air eventually exits the thin slit in the ring, it “sticks” to the sides due to the Coandă effect and produces a low pressure zone in the center. That’s all a fancy way of saying that the air flow you get from one of these gadgets is several times greater than what the little dinky fan would be capable of under normal circumstances. That’s the theory, anyway.
We can’t promise that all the physics are working as they should in this 3D printed version, but in the video after the break it certainly appears to be moving a considerable amount of air. It’s also quite loud, but that’s to be expected given it’s using a brushless hobby motor. To get it spinning, [Elite Worm] is using a Digispark ATtiny85 connected to a standard RC electronic speed control (ESC). The MCU reads a potentiometer mounted to the side of the fan and converts that to a PWM signal required by the ESC.
Beyond the electronics, essentially every piece of this project has been printed on a standard desktop 3D printer. An impressive accomplishment, though we probably would have gone with a commercially available propeller for safety’s sake. On the other hand, the base of the fan should nicely contain the shrapnel created should it explode at several thousand RPM. Probably.
dyson’s lawyers are warming up their suitcases I bet :P
To late now!
Mrs. Streisand know that ;-)
Plus people will have already downloaded it. Not me, I don’t download stuff. Other people, yeah, that’s the ticket.
https://youtu.be/ALZZx1xmAzg
If you’re going so far to use a uC you could pass three PWM IOs through low pass filters to FETs along with some rubber mounts to make it near silent.
Does that actually work? It seems like you would need at the very minimum half-bridge for each phase. I guess linear mode driving could work with small loads, but it seems like it would need adjustments to the control algorithm also. Or do you suggest driving it just open loop at constant frequency?
There’s a microcontroller on the ESC that does just that. Really, he could have reprogrammed just that uC to take an analog input from a pot instead of needing a whole other uC just to read the pot and provide the PWM signal the ESC expected. I suppose he just followed the path of least resistance.
I’m betting a design like this would work better if driven by a “squirrel-cage” blower instead of a fan due to the higher pressure.
That’s not how squirrel cages work.
Obviously the shape of the base would have to be tweaked. It would probably need to be a tall box instead of a cylinder. And I think there would need to be more holes on the intake sides. I don’t see any problem that couldn’t be adapted by re-orienting some things. It would lack elegance but maybe it would work better
I’m guessing Steven was talking about an involute-style blower, like this one: https://www.thingiverse.com/thing:135718
“To be clear, of course there’s a blade. They aren’t magic, obviously. The fan is just small, and hidden inside the base.”
See, this always annoys me, because there are plenty of non-magical bladeless air pump designs one could fit in an enclosure like that.
Perhaps a candle to cause convection for a fan heater effect or a plasma discharge for an OTT ioniser?
I am not sure, if I want a fan with a noisy piston air compressor in my living room. :)
What about screw compressor? They are shockingly quiet in my experience..
“The MCU reads a potentiometer mounted to the side of the fan and converts that to a PWM signal required by the ESC.”
What has HaD come to when the de rigeur snarky comment about a well known astable multivibrator hasn’t been posted 5 hours in, moreso when it’d be accurate?
You mean “why waste the time coding a micro when you could just use a 555 timer and get the job done in a fraction of the time”?
Couldn’t resist…
Need to see a pulse jet bladeless fan!
That should help with the noise!
Sounds like a job for Colin Furze…
Nice print quality.
Her: “Turn up the fan.”
Me: “I can’t hear you, the fan’s too loud.”
I was so annoyed by the “bladeless fan” marketing wank some years ago that I boycott the whole thing.
Just because it sounds catchy is no good reason to blatantly lie to your own potential customers, and yet people seem to accept it as “normal” that marketing and advertisement companies do nothing else.
These things probably also make more noise than “regular” fans, which makes them less desirable to have then the old fashioned variant.
And what do you mean with “To be clear, of course there’s a blade.”
Never heard of, for example:
https://en.wikipedia.org/wiki/Ion-propelled_aircraft
Dyson mission statement: regurgitate established designs in flimsy brightly colored plastic, integrate planned
obsolescence, add a dash of British accent, declare innovation, and profit!!
“I boycott the whole thing.”, “These things probably also make more noise”. So you don’t know?
Those “things” or more accurately the original one is called (by marketing not by engineer) bladeless because less than half of the air flow is coming from the fan; so this is quite fair.
“Air Multiplier™ cooling fan technology exploits the Bernoulli principle, which creates an area of low pressure. This induces air behind the fan, while surrounding air follows the airflow in a process known as entrainment – amplifying the initial airflow by as much as 15 times.”
Also this reduce turbulence and so the noise.
this require a bit of “aeronautic” design like shown here https://www.dyson.com/fans-and-heaters/dyson-cool-technology.html
Of course. We know that advertisement – like politicians – have a very stretchable attitude to “truth”. :-)
So – like scientists – just test one when displayed/advertised in a store. for low noise they just work …. as advertised. Same air flow than one with fan……. without the fan….. without the sound etc…
Maybe it needs a digital motor
Must be how they “solved” the intolerable “buffeting” of traditional fans
replaced buffeting of traditional fans to buffering of digital streams
Ironically, it HAS a “digital motor”, they only missed the opportunity to call it that…
Now we have all engineers here: has anyone a rough estimate on how the efficiency of such a thing compares to that of a more conventional design?
Whats so special about this? Goto thingiverse and theres probably a hundred variations of this you can download and print.
https://www.thingiverse.com/search?q=bladeless+fan&type=things&sort=relevant&page=1