I 3D Printed a Compressor that ACTUALLY WORKS (but you've never heard of this design)

Time to report out on the Regenerative Compressor project! I didn't mean for the opening of this one to sound salty, so I hope it doesn't. I was mainly hoping to establish why trying to FDM print air compressors is one of those things that looks easy, but is actually a tough engineering proposition and maybe not advisable if you want performance ... at least, UNTIL NOW?
You can get STLs for this design (all parts now posted, and instructions are updated for multi-stage builds) here: www.printables.com/model/2543...
STLs for some cool demonstration accessories are now posted here: www.printables.com/model/2891...
Trihorn cooling duct STLs from the VzBot github: github.com/VzBoT3D/
Tips/donations if that's your thing: ko-fi.com/jamespray
I'm also a writer! I don't care that much if you mash dat like or smash dat subscribe (I mean, don't NOT, but it's cool, we're cool), but if you like sci-fi adventure stories, check out my debut novel, JONESY FLUX AND THE GRAY LEGION: bit.ly/JonesyFluxAZ
Or visit me at:
www.jamespray.com
/ jamespray
/ jamespray.author
Timestamps:
00:00 Introduction
00:38 FDM Printed Compressors Suck...
01:05 ...And here's why
01:24 A better way?
01:30 CAD Overview
01:49 How it works
02:53 First prototype build and review
03:29 Solving the noise question
04:15 Performance review
04:58 Multistage upgrade
05:31 Nice pictures I guess
05:56 Final performance metrics
07:07 Looking forward, le sigh
08:01 Post-credits secret scene
Music credits:
Track: MILANE & Greg Aven - Like You [NCS Release]
Music provided by NoCopyrightSounds.
Watch: • MILANE & Greg Aven - L...
Free Download / Stream: ncs.io/LikeYou
Track: Raptures. & DigEx - Feel [NCS Release]
Music provided by NoCopyrightSounds.
Watch: • Raptures & DigEx - Fee...
Free Download / Stream: NCS.io/Feel
Track: Elektronomia x Lunaar x Donna Tella - Champions [NCS Release]
Music provided by NoCopyrightSounds.
Watch: • Elektronomia x Lunaar ...
Free Download / Stream: ncs.io/Champions
Tags and stuff:
3D Printed Compressor
3D Printed Turbocharger
3D Printed Supercharger
3D Printed Blower
3D Printed Roots Compressor
3D Printed Screw Compressor
3D Printed Side Channel Compressor
3D Printed Side Channel Blower
3D Printed Ring Blower
The best 3D Printed Compressor?
3D Printed Compressor that doesn't suck
3D Printed Compressor that actually works
How to print compressor
Delta 3D Printer
FDM Printing
Major Hardware
Fan Showdown
CPAP cooling
CPAP blower
CPAP compressor
Printer Layer Cooling
The best print cooling
The most powerful print cooling

[@jamespray]

🖐Hey ya'll! If you're wondering what else this compressor can do, check out the follow-up video where I design and goof around with a mini bladeless fan, venturi vacuum, and more 3D printed accessories: kzbin.info/www/bejne/hKaVaqyie7GoorM -- cool "smoke" and glitter tank tests, plus dizzying CAD timelapses and boring channel news! Also, I want to apologize again for the audio on this one. Old headset + newb editor = dumpster? I've got a better recording setup for future content, promise 👼

[@AET_DH]

Hey amazing design! I think I'm going to try to implement this as a compressor for a hobby-laser cutter/engraver air assist. I'm betting it'll beat out the best aquarium pump by a LONG shot!

[@jamespray]

@@AET_DH Thank you :) Sounds like a great application!

[@karaabdelkader1273]

​@@jamespray how powerful was the engine tho?

[@CUBETechie]

It would be amazing to connect it to a Drill

[@ArcAiN6]

Coil wind when using PWM is quite common, if you change the PWM frequency, you can significantly reduce coil wine

[@mikescholz6429]

You can also put some clear nail polish on them to hold the wires still, because the whine is the high frequency vibration of the coil wires.

[@paulo-kiefe]

You designed an amazing compressor! Thank you for sharing it on Printables!

[@jamespray]

You are welcome! Thanks!

[@MakerMindset]

Loved your project! Never thought that a 3D-printed compressor was even possible! Keep it up!

[@jamespray]

Thanks! It might be a while (other stuff to get done), but I do want to explore improved designs in the future. It would be cool to shoot for something that was both cost-effective and capable of doing some common real-world task, like power an airbrush. We'll see!

[@MakerMindset]

​@@jamespray It's so funny you said that! I purchased onAmazon a "Quiet" compressor because I wanted to drive an airbrush. That thing never worked well. As soon as I saw your video title I thought of using it to drive an airbrush... I am already a subscriber. I will keep an eye open for your future projects. Let me know if I can help you in any way like, for example, a beta tester of your project or something! 😁

[@jamespray]

@@MakerMindset Good to know an airbrush compressor might be a project with some takers! It would have to have roughly inverted performance characteristics to this one, with a minimum 10PSI and 1CFM flow. Since adding stages increases PSI but not flow, it might work to have a larger number of stages that were thinner and worked on a much smaller volume of air. It would be a very interesting experiment to see how the performance changes with different design characteristics like that. And if it was actually quiet on top of building high pressure head, that'd be a big deal!

[@lazerusmfh]

Pretty awesome! If cost isn’t an issue you can use a brushless motor with a VESC and run it in FOC mode. Super quiet

[@fishyerik]

Finally! A DIY multistage compressor video! Personally I think a simple centrifugal turbine design and more stages might be better. Ideally many more stages. Regenerative compressors have their advantages, but also disadvantages, for one, they're not very energy efficient. Nice work, nice video, interesting and funny.

[@jamespray]

Ideal is the keyword! This was a study in ideal vs practical within the limitations of a given manufacturing technique, but I think there's plenty of room left for development in all sorts of FDM printed compressors. Thanks for the feedback, much appreciated!

[@crankhandle]

Very cool design!

[@OregonDuck]

About to crack open your book after I finish up my current one! Thanks James for sharing your findings.

[@jamespray]

You're welcome! Hope you enjoy the book!

[@axelr.8766]

Impressive engineering!

[@thedanyesful]

Very cool project!

[@AstroCharlie]

This is an awesome design!

[@jamespray]

Thanks!

[@user-kn9kc3wu2e]

Why am i even watching this? I know nothing about compressors, aerodynamics, (maybe) physics, and why is this so mesmerizing to watch?

[@jamespray]

Haha, there's just something about compressors 🤷‍♂️ I don't know what!

[@goeland86]

This is impressive and very interesting. I may just have to make one for my Monster Kossel design. Right now using a brushless CPAP fan, which costs $70 with the driver. Easy enough to control from the PWM with the built-in controller, but still louder than I like.

[@jamespray]

Thanks!

[@albertoplm]

A really cool design

[@mitsubishimakes]

Awesome job!

[@martylawson1638]

Nice results! 1.2psi boost is an excellent result with the relatively low tip velocity limits of 3D printed parts. I've also experimented with small regenerative/side-channel blowers but stopped because of the noise. Was planning to do a resonant muffler, but would probably now do a packing muffler since it worked so well for you.

[@jamespray]

Thanks for sharing your experience! The silencer/muffler really made all the difference for comfortable experimentation (my wife was NOT pleased with the early testing and I needed ear pro for full throttle, but afterward I could get away with short runs even after the kids were in bed). I ran with this silencer design partly because it seemed to be the most common commercial offering, and partly because of the compressor's flow rate. The simplicity is a bonus: I actually started with a rolled-up kitchen sponge stuffed into the silencer housing, and it worked nearly as well as the final design with the printed liner. If this compressor made higher pressure and lower flow -- which I'd like to shoot for with future designs -- I would probably experiment with baffle-based designs to see if the noise could be cut further, as well as try them on both intake and outlet. If you do experiment further, I'd be interested to hear how it goes!

[@martylawson1638]

@@jamespray The geometry of the "stripper" where the rotor passes from high to low pressure also makes a big difference. Only got far enough to figure out that angled strippers were better than flat ones parallel to the blades. Might be able to improve further with strategic leaks?

[@jamespray]

@@martylawson1638 I have actually been thinking of strategic leaks too! The current design has a circular air dam that is unbroken even through the blocked portion after the stripper (as you can see in the CAD), but I've been wondering if it might be better to remove it so high-pressure air passing the stripper between the blades could be leaked/bled into the central area. That would not only reduce the pressure of what's released at the inlet (possible noise benefit?), it would increase the "backing pressure" behind the air dam and might make it a more effective seal. I also would like to explore leveraging the vortexes themselves in an improved stripper design. The next design I want to build will use airfoil blades to create a single vortex around a donut-cross section channel, and one reason for that is because I think it'll make it easier to strip the airflow straight down into another stage by stripping it at the point where it's moving downward anyway.

[@user-xe8oi5oq6c]

@@jamespray It's a nice idea! Thanks for great video! What you have already built is vortex pump. It MUST be very loud. Industrial ones use mufflers on both inlet and outlet and you did it well. Important thing about vortex blowers - they have 9 times higher flow than centrifugal ones. It seems that these 9 times is what compensates all the leaks due to 3d printing tolerances. If you want another thing to try, you can print Lyssholm compressor.

[@user-xe8oi5oq6c]

@@jamespray Yet another turbine, interesting to try is Ljungström one.

[@MsFactnotfiction]

That is awesome. I want to build one to supply air to my milling machine chip evacuation, it needs a lot of air but no much pressure. I want to limit to 300/500 watts and noise is an issue. I love your design and the size is perfect to me. Very nice work.

[@jamespray]

Thanks, I'm glad to hear it! That sounds like a great use case for this. I am testing a variety of attachment designs right now, and I can confirm that it works well with things like blowoff nozzles, air edgers / knives, etc. (Should have a video to demonstrate those soonish.)

[@PacoMorales]

I am planning to try out this design for my airbrush!

[@jimmym2719]

Good job..After seeing lots of others made n explode I kinda gave up the wanna 3D print built..this could be the One I when I saw the plastic bag burst. That’s more than enough of what I need. Thanks for sharing your wonderful work bro, you are aweome.

[@jamespray]

You're awesome!

[@positron5687]

Thank you, please more

[@jamespray]

More compressors soon :)

[@tyreksimmons4167]

i was actually trying to build the same type of pump, i know it as a side channel pump, (thought these only worked with water) i spent a bunch of time trying to put sealing everywhere with tphu for smoother movment, good to know you dont *really* need sealing!

[@jamespray]

Haha, yeah! Not perfect sealing, anyway. Keeping the air in the housing is fairly simple. The moving "seals" have to be accomplished with tolerances and geometry, not contact. The closer the better -- but it's curtains if anything starts touching in there! With the PLA I used, I tried "running in" some rub lines first, but the friction heated the plastic enough to start raising it like crocodile scales and seized up the works.

[@simonlaker2139]

I rebuild and repair a lot of side channel blowers. They run extremely hot. They normally have a support bearing in the front casing which when running runs at least 90deg c. I always love running them in after a rebuild. They sound like a jet engine. Great work

[@jamespray]

Thanks! I was very surprised by the jet noise at first -- I heard "low RPM" and assumed that meant "quiet", and then the first spinup sounded like an F16 on the runway! The heat in the "real thing" is interesting, something I didn't know -- is that just from pressurizing the gas also raising the temperature, or do the motors run hot too?

[@simonlaker2139]

@@jamespray I'm not a engineer just a tradie. There mainly used for vacuum applications rather than blowing air. We rarely get the hole unit. But sometimes we get the unit with the non return valve. There used in plastic extrusion machines, they use them in the hoppers that hold the beads. I think it's a charge created from compressed gases and friction. But most likely friction There would be charge there flowing from the shaft currents of the motor creating a Edie current when passing over the aluminum in the industrial ones. Good to see you went to the double stack type. I've done up to 3 in line being run by a 16 kw motor. Siemens bring out a large range of the side channel blowers. They mostly have the issue with the hot bearing at the front. The style you made are pretty good. Don't seem to have the same issue.

[@jamespray]

@@simonlaker2139 Thanks for taking the time to share this info! Mostly new to me, and good to know. 👍

[@crottemole]

Really interesting video! Never knew these compressors existed.

[@jamespray]

Thanks! Yeah, it was kind of a total accident that I found out about them, lol.

[@Athiril]

Looks good.. for compounding like this I think the results are better if the first stage wheel is larger, and smaller outlet than inlet, so start off with large first stage inlet, medium first stage outlet that matches second stage inlet that comes out of second stage outlet that’s small. Like a compound turbo.

[@jamespray]

Hopefully something I'll be able to experiment with in the future. Thanks!

[@radicalphil1871]

Since I now searched more for better medium pressure and medium flow fans, I came across multistage centrifugal fans. Building those might be a little more compact and can be optimized to fit the needs of a 3D-printer.

[@jamespray]

There's a use case for just about every setup! You can even multi-stage commercial blowers (e.g., 5015s) by stacking them outlet to inlet with adaptors. I have done this in the past and it works well to improve pressure head (though the flow stays about the same). I just wasn't a fan of the noise (I know, ironic, considering how this compressor sounds).

[@radicalphil1871]

@@jamespray I know what you mean. Also tinkering around with own fans is a lot of fun! Hopefully a multistage blower fan is good. But eventually I'll go for a 7040 CPAP fan like mentioned here: kzbin.info/www/bejne/jWnLmKiqrqx3n7M Costs around 80€ and should be THE solution. Still I want to find my own solution.

[@idemanddonuts]

hi, I'm an electro-mechanical engineer and I wanted to let you know that electric motor have power, torque and efficiency graphs and each style of motor has their own. so if you're doing a lot of 3D printing with these compressors I think it should be worth your while to optimize the gear ratio so the compressor and motor are at the optimal RPMs. and if you're running the motor RPM it may be warmer because of the power output being put out at a lower speed. something definitely worth looking into.

[@jamespray]

I appreciate the input! I have been figuring this out empirically (from measured RPMs and motor temp at various ratios) along the way, but I know I have a lot more to learn. In particular, I don't know enough about acceptable/expected operating temps for different types of motors. If the motor temp skyrockets in seconds, I assume that's an obvious sign that the gear ratio is too high, but I'd like to be better at quickly determining (from steady-state temp, RPMs, other data?) what's optimal...

[@idemanddonuts]

@@jamespray temperature is usually stamped on a metal data plate. If you got anymore questions feel free to shoot them my way

[@carteradams1079]

Wow that would work really good with fluids

[@codyvangordon1822]

this is an awesome concept, I have been trying to formulate a way to "optimize" my experience with my 2002 Toyota Celica, the 1zz-fe that came in them is NA and the engine wont handle big boost well without a bit more work then its worth at the moment. Having thought experimented over many options only to find out that the price is not within reach for awhile (centrifugal superchargers, small turbos, converting a turbo to a centrifugal SC, using some version of an electric turbo that wouldn't have extensive load on the 12v electrical system in a car). This is something that I can build off of to create a proto-type electric - small boost super charger essentially... figure you can mount it just behind the filter and map a variable speed motor to a set of rpm's at which the compressor would change speed to either generate more or less boost for the desired effect (could be a giant waste of time, however I know an amazing alternator shop that can make me a nice and beefy alternator for more available power in the system, I own a 3d printer, don't imagine I will need a ton of boost as the intake flows like crap on these engines and my car is extremely light so I would like to compliment the low end torque for fun, and the fuel economy at highway speeds) would love any input on the idea from the community! Once again I must say the channel and concepts are awesome and I very much so enjoy the content!

[@jamespray]

Glad you're enjoying the content! I have no idea about the suitability for your application, but it sounds like a fun experiment! Just be sure to use materials that can handle your engine bay temps 😉

[@codyvangordon1822]

Agreed, would not go into the bay without some serious trial and error, I do like my car running and all 🤣 but all in all very interesting and enjoyable content... my most "fun" item with my printer so far is making a series of golf putters with petg and some iron oxide suspended in epoxy for weight

[@leonmusk1040]

Fully encapsulate the top and bottom of the blades and housing and run a tapering channel to spill the air into you can use an impinging flow channel to get high pressure when it couples with the bulk spill air like a delavel nozzle running around the outer edge of the toroid where the opening is the outlet just a hint for future developments same as under an f1 car or the inflatable slide on aircraft.

[@scottmeyer5900]

Consider a large DC Brushless Motor and ESC. For your target rpm, a 4-6s lipo battery should have plenty of power. An air bleed channeled over a heat sink on the motor would aid in keeping the motor cool

[@falin9557]

to reduce noise due to PWM frequency, you can try to increase the frequency and adding a low-pass filter to it

[@aruneshkr6487]

WORKING thx bro

[@jamespray]

Heck yeah!

[@Lucas_sGarage]

Literally i just uploaded my video of a supercharger, and a few hours later KZbin recommend this video to me, great one dude

[@jamespray]

Printing compressors is the best! Congrats on your prototype making measurable static pressure. That's not easy!

[@Lucas_sGarage]

@@jamespray thx a lot dude

[@db345t]

been thinking of building a Wankel compressor / vacuum pump so yes i can agree the rotary engine has possible benefits and can be combined with other pump designs to equal a better fine stage. Integra has designed and printed a lot of Wankel engines i suggest checking him out.

[@jamespray]

I do love Integza! Wankel designs have too much sliding seal surface area for my taste and I don't think they're the most viable route for an FDM-printable compressor (as a demo, sure, but not as a long-term tool), but I'm always willing to be proved wrong. Clever solutions can often get around such limitations.

[@pesho9971]

You could try using DC current control intead of PWM if you want a more quiet motor.

[@manray8513]

thanks man! this is what i need, btw you can control it with a BTS7960 and other motor that are quiter is 795 and 997 but don't go for 895 that beast is loud

[@jamespray]

You're welcome, and thanks, I'll check out those parts!

[@clementclarisseclemen3d708]

Maybe (and i said "maybe") if it was'nt already done, you should consider screw compressor, they're also quiet, efficient and easy to print/build/integrate...

[@jamespray]

I've never seen a 3D printed screw compressor that built measurable boost, and the ones I have seen sounded like cans full of rocks before they blew up. If you know of one that does work, please link! I think it'd be an interesting challenge to design, but I don't have great hopes for getting one working easily.

[@radicalphil1871]

Awesome video! Really! Compared to others, this video and your humor are just awesome and sooo ... regeneartive! Thanks a loooooot for this video! Oh yes: how about giving this compressor the outside look of the Millenium Falcon?!

[@jamespray]

lol, thank you! Maybe I'll have to add that side-cockpit 😉

[@Bandicoot803]

Excellent job there, sir! Aswell for the CAD insight. No one else on KZbin has taken us to a journey into a side channel blower. Oh, by the way, you might one day replace the brushed motor and timing belt with a direct-drive brushless motor for increased longetivity.

[@jamespray]

Thanks, glad you found it useful! I do plan to play with other power sources as time permits... And there is one other guy I know of who's been playing with side channels called turbo print3d, if you want to see more experiments with a slightly different design.

[@tvathome562]

Next evolution in 3d printing, better bed adhesion to stop prints being blown away? Great work

[@jamespray]

lol, thanks!

[@Veli-PekkaLehtosaari]

This is awesome video, thank you. Just thinking of POC electric turbo for gasoline motor. Would need around 200CFM and 1.5-5psi of boost. Dont much mind on the electric motor but just thinking with current consumer printers is this the regenerative compressor the only option? And is it impossible to get more boost than 1.25 or so?

[@jamespray]

I am not aware of another printable design that could get 5psi of boost safely. Of course, I haven't proven that this design can get 5psi, but it could definitely get more than 1.25 with a bigger motor. You would just need more power to spin it faster. 200 CFM is a lot, though. As stated in the video, in the 4k RPM range where this can deliver 1.25psi static pressure, it only hits 11CFM at free flow. I don't know much much CFM it would deliver at the RPMs need to hit 5psi, but I have doubts it would be in the 200s. This design is balanced toward pressure rather than flow.

[@eliweitzman9993]

Try to make a liquid ring pump! You might be able to get a decent pressure ratio with mostly home 3D printing.

[@DrJimBoston]

Thanks to YT algorithm I couldn't find this video month ago. Now I designed, build and tested my turbine runing on 775 XD with GT2 belt transmition 1:2. It works but it's loud. I need to build intake muffler. I have no idea how to check pressure or CFM, but it can blow an latex baloon is few seconds. I didn't want to buy CPAP, it's to expensive amd I need it for my Corexy project.

[@jamespray]

You can measure CFM by filling a garbage bag of known volume (see how I did it in this vid) and timing the fill to get volume per time, and you can get an idea of pressure by measuring how far below water surface it can push air through a tube (use a jar or pitcher) - mmh2o or inh2o can be easily converted to any pressure units you like!

[@jamieclarke321]

Serious question, could this be scaled up to 400mm in diameter and used for the vacuum table on a CNC machine? Vacuum tables normally use these side channel blowers/ regenerative compressors and I have a ratrig 400 so I could print a 400mm diameter housing

[@jamespray]

I don't see why not (component scaling or reworking stuff like the bearing sockets would be the biggest task). I think it works best when it's got some level of airflow to keep those vortexes turning, so as long as the vacuum table wasn't completely covered it might work. And going bigger could really only help the performance!

[@2kadrenojunkiegaming655]

low rmp centrifugal compressors already exist albeit hard to find examples of. you usually need at least 3 stages for decent throughput at higher pressures and they have a tendency to explode at high rpm. honestly though for 3d printed parts multistage axial plus 1 or more stages of centrifugal at the end depending on pressure needs is ideal. you can legit get ~10 psi max from axial compressor stages and they are super compact to stack with high tolerances. a old 100 stage one i made for shits and giggles would literally blow up the walls of the compressor if you managed to plug up the end. the outer wall was 1mm thick aluminum cast tube with steel wire mesh inside. stators and rotorblades were made out of cardboard(not corregated) while the main shaft was a 6ft piece of rebar with aluminum bushings. at 30 rpm the output pressure was ~130 psi before rupturing. note that the failure mode was not the cardboard parts despite being the ones imparting the energy. this is because despite the absolute pressure being very high near the end the pressure difference across the stages was actually quite low (~1-7 psi depending on the stage). it should be noted however that while axial compressors are technically more efficient in terms of static pressure you'll need a lot more stages to get decent pressures. do note that despite having high tolerances it does effect the performance somewhat if you are too loose and also while you can use something like cardboard its not recommended due to frictional losses (the air that came out of that behemoth mentioned above was hot enough to cook with despite less than half a rotation per second, its not supposed to do that)

[@jamespray]

Interesting! Most likely the air coming out of a 130 PSI compressor cascade would be very hot regardless of frictional losses because that's an inevitable side-effect of compression. If the cardboard compounded the effect it was most likely by being an insulator instead of drawing the heat into the housing....

[@2kadrenojunkiegaming655]

@@jamespray to clarify, i was talking about after letting it expand into a open room. also i know it wasnt just from insulation due to the input power being kinda absurd(~5kw) with a somewhat pathetic flow rate

[@mystamo]

I can't believe all this incredible 3D printing stuff you are doing then using a brushed motor :O

[@jamespray]

lol! I just had no use case for one before now, and the ones that would be worth slapping on this are pretty pricey. Wait til I mount a salvaged dyson motor on it or something ... I doubt it'll be disappointing 😆

[@mystamo]

@@jamespray if you put a period in between my name and last and send an email to icloud I'll gladly send you a brushless motor and controller to support the cause.. I wanna see this thing wurr.

[@jamespray]

@@mystamo That is super-awesome of you to offer, but I'd feel super-terrible if I took it and then landed a book sale that would push out my next "proper" video by a year+. Don't worry, I will make it wurr but good, as soon as I can! It's just a B sometimes balancing all my projects... Thanks in any case, and cheers!

[@mystamo]

@@jamespray Ha! I was trying to hold you accountable :) Kidding, let me know any time. I have so many motors and controllers that I don't know what to do with...

[@fabianrudzewski9027]

The motor noise problem is really easy to solve, go higher in pwm requency. Almost every Hobby grade brushed ESC supports 16k pwm, which is mostly inaudible. They're available from like 8 bucks in China. Or just go brushless. With a correctly sized outrunner, you could go direct drive and drop motor rpm to further quiet things down and be super efficient.

[@jamespray]

Higher PWM can help, but it comes with the tradeoff that you start to lose the ability to run slow, at least in my experience? But a brushless might be more forgiving on that than what I'm using right now. Definitely an area I'll be experimenting with in the future, once I figure out what "correctly sized" looks like. The power demands of this design are no joke -- if I chase DC instead of AC, I'll probably have to look at something like an ebike motor. Thanks!

[@fabianrudzewski9027]

@@jamespray the pwm frequency should normally be independent from resolution, but no idea, if you might loose low end resolution through some effect. At least in the old brushed RC cars, I didn't have problems with low end controllability at 16k pwm. By correctly sized I mostly meant the KV rating, so that you don't end up bogging down a high revving motor or don't have enough rpm available. Heavily oversizing current capabilities won't hurt. For example, if you want 5000rpm and plan on using a 12V powersupply, in theory you would need a 5000rpm/12v=416kv Motor+a little extra. Finding a powerfull enough motor will be the last of your issues, trust me. You'll run out of powersupply before you can't find a motor that can take it. I played around with the compressors side of a little Turbo and a 4074 brushless inrunner. That pulled around 100A from a 22V lipo, so yea, power won't be the issue.

[@jamespray]

@@fabianrudzewski9027 Power supply is a bit of a sticking point and part of the reason I'm tempted toward AC, but I have to admit you're swaying me on BLDC's power capabilities! Mainly, I'd love to not be stuck doing bench tests with batteries, but high-amp DC PSUs are expensive if you want a decent/safe one...

[@magamagaaa]

sweet video man, came up in my rec

[@jamespray]

Thanks dude!

[@rolohaunaiart988]

excellent!

[@jamespray]

Thanks friend!

[@chipskylark9352]

great video. easiest sub ever. look forward to more!

[@jamespray]

Very kind! Cheers!

[@austinbarnett1]

I swear that google has a direct feed to my brain. I was just thinking that I needed to build a compressor to fill our stand up paddleboards, and prove to my wife that the 3d printers we have aren't just toys.... I hadn't even started to search for such a thing, and wham, youtube throws it in my face.

[@jamespray]

Does Alexa spy on conversations with one's spouse? 😨

[@steveaylor376]

This was a cool video man ... thanks fo sharing - impressive design too. However; not sure I heard it running ... quietly ??? Whats it sound like when its operational for printer cooling. Im running a voron 2.4 - would be interested in something like this or CPAP

[@jamespray]

Thanks, glad you liked it! It's really hard to convey the noise levels on camera, unfortunately. At lower RPMs before the intake whine kicks in, NOT counting the motor, it's as quiet as, or quieter than, a good bathroom exhaust fan. At the highest I've been able to push it so far in double-stack configuration, it's maybe as loud as my wife's hair dryer on high, just higher-pitched. I hope that helps!

[@Luigik99tv]

wow impressive work congrats ! hope to see this kind of compressor in a car maby 😂

[@jamespray]

Thanks 😄🏎🏎🏎

[@SianaGearz]

Put an inductor in series with your PWM signal and after the inductor a capacitor across to voltage control the motor so you don't have it sing a PWM song to you. You could even do a reverse pi of sorts.

[@jamespray]

Good tip, hadn't considered adding an inductor! I'll keep it in mind. Thanks!

[@fabianrudzewski9027]

Or just go higher in pwm frequency. Most hobby grade speed controllers support at least 16k pwm, which is almost inaudible.

[@l0k048]

that compressor may be useful for me one day, even though i don't even have a 3d printer yet lol, also you got a new subscriber

[@jamespray]

Good deal! Cheers 😀

[@rafaelthetall]

to increase pressure make the stages smaller. (the larger is the first stage)

[@DigBipper188]

One way you can really quieten that compressor down would be to go brushless :) I'm using a 3300kv 540 RC motor on a turbine and that thing at 12v is absolutely ridiculous. the only noise I'm getting is from the inducer and the vast amounts of air that it's flinging about. Especially if you can find a sensored motor and an ESC that can do phase angle control, the damn things are basically silent in normal operation.

[@jamespray]

One struggle is finding really low KV RC motors. It's hard to overstate how different this type of compressor behaves from a centrifugal blower, but in testing recently I determined that this pushes about the same pressure and CFM as a ws7040 CPAP blower ... at *one tenth* the RPMs(!) ... and it wants at least as much power at that level. And it's hard to make space for more than a 1:3.75 belt reduction. So most BLDCs in the hobby space just won't work because they're such high KVs. Maybe a crawler motor?

[@turboprint3d]

I have herd of this design lol , nice work ! Do you think the closed impeller is better? Mine is open on the end , and I would Imagen it gives larger traction area , but I may be wrong . Yours is much larger than mine so the physics might change . Way higher flow rates as well . Have you seen what I'm up to lately , I made a 2 stage version of my 60mm Regen and it's now coupled through a gearbox running on a 13 hp engine

[@turboprint3d]

Oh the idea of a Rotorua engine is good . My idea was to split the housing horisontly and have a flange to booth the halves together to be able to stage them up . However I think the improvements will eventually become more and more costly with less and less improvement per added stage over 2 . My 2 stage design steps down the ports , intake largest , inbetween about half and the output smaller to increase velocity thought the compressor .

[@jamespray]

@@turboprint3d I know YOU'VE heard of it, lol! Your geared build is super cool. I don't think the closed impeller is better or worse, necessarily, but I think it probably performs differently than an open one (flow vs pressure ratio). I wanted to move less air but push harder on the air I moved, but these things don't act intuitively, so who knows. I am also thinking to split the housing in half to add more stages, same as they do with gas turbines ... that way the impeller can be built and balanced first and the housing installed around it. We'll see how much difference it makes, but it will save on bearings, at least!

[@guerrillaradio9953]

Aaaaaaaaaaand just when I thought I had heard about every main type of compressor and pump imaginable.....nope! It sounds killer, too! (Assuming one enjoys shrieking jet engine noises, which I do, but not INSIDE lol) I'd be willing to bet each successive stage after #1 is going to need to be progressively smaller, like any multistage compressor. Fortunately, this is an area where it's definitely FDM ftw...now I need to build one and make some glorious jet noises.

[@jamespray]

If you want jet engine noises, this can certainly deliver! I'm genuinely unsure about sizing subsequent stages, though. This behaves fundamentally differently from centrifugal compressors (I mean, just look at the operating RPM range) and what little I've been able to gather design-wise from commercial/industrial models is that the main consideration is simply the length of the working passage(s) -- consider that unlike a centrifugal comp where the pressure rise is radial (hub to edge and then through the diffuser, if any) via a path that changes in volume from start to end, the pressure rise here is around the circumference of the disk, through a passage that is constant in cross-section. That suggests to me (and I'm not an expert, so take all with a grain of salt) that the compression happens because the air is "packed" between the backpressure and the vortexes in the working passage that resist backward flow -- a very different compression mechanism vs centrifugal comps that work by working air up to high velocity and then compress it via expansion to trade the velocity for pressure. Not that I think it's ideal to have identical stages in a regen comp, and perhaps sizing down would improve efficiency, but my personal intuitive take (at the time of writing) is that the blade design in each stage may matter more for optimizing performance for the average air pressure and characteristics at each stage.

[@guerrillaradio9953]

@@jamespray I think it would be more akin to an axial compressor with respect to each successive stage becoming smaller in swept volume, but also in shape slightly, as you've suggested. As far as staging goes, while yes, you're absolutely right that the mechanism of action is entirely different, I'm simply thinking of each stage as a "box" with an input of x amount of air at a starting pressure, and an output of y (~ that same amount of air minus friction/adiabatic/other losses, at a higher velocity/pressure based on restriction). Treating each stage as such, it's potentially possible (although overall woefully impractical) to make a multistage regen compressor. It won't make flight weight, but it would sound really awesome!

[@Mr0o0o0o0o0o0o0o0]

cool project!.. what kind off pressure can you sustain with it?

[@jamespray]

My current record for completely blocked flow is 1.25 PSI, but that is with a fairly smol motor, not an upper limit on the compressor itself. Eventually I will try a very big motor on it and I expect much more 😉

[@jonmichaelgalindo]

Huh. Awesome research. I planned to look into 3d printing a compressor eventually, but I was going to use flexible bellows, not a spinning wheel. Walls printed like: |^|_|^|_|^| ... Like an accordion, are extremely flexible no matter what filament you use.

[@jamespray]

Somebody else just mentioned a bellows compressor as a potential 3D printable design, too. You should go for it! I think it could work if you could get some decent airtightness out of the thinner walls. Probably it would get more pressure but much less flow than this design, but it all depends on the flow vs pressure stats needed for your use case.

[@jonmichaelgalindo]

@@jamespray I have high hopes for it. :-) I'm picturing something like the cylinders on a combustion engine pistoning. The cylinders are accordion bellows, and the camshaft is driving them.

[@Andrew_Custodes]

To reduce a PWM - Song you need to install a ceramic capacitor on between motors terminals

[@jamespray]

Do you know of any good resources for sizing them? I tried a random smallish one from my collection and it didn't seem to help, but it seems like if it's the right capacity it ought to do something...

[@DailyFrankPeter]

Hahahahahahh, the part about 3D printing as the right process for building compressors is so true!

[@DarkIzo]

very interesting nice demonstration ride the algorithm wave, brother

[@jamespray]

lol, thanks! The eye of Sauron, err, algorithm, is on this one for sure 🤣

[@Chris-oj7ro]

How does this compare flow-wise, pressure-wise, and power-wise to the CPAP?

[@jamespray]

Versus a 24V CPAP blower like the VzBot uses, it's broadly similar, but maybe 25-35% more static pressure at stall, 25-35% less flow at free-flowing, and similar power usage.

[@AK-vx4dy]

There are more advanced controlers for BLDM motors wich vastly reduce sound on low rpm, i don't rember name of channel right now, but some guy showed this. Is this design is used in CPAP machines ?

[@jamespray]

CPAP machines use centrifugal blowers at about 10x the RPMs. The main real world applications for this type of compressor are (as I understand it) for generating industrial compressed air at high flow rates, like you might need for blowing off parts on an assembly line.

[@Brickedaboss07]

I want this but as a car turbo made from metal to see how it effects the efficiency and power of the engine

[@RAZERTAHP]

Would love to see a rotary engine style cpap pump

[@jamespray]

Me too ... maybe someday!

[@pizza6447]

you should get brushless motors

[@freznelite]

How do you get all those fancy threads to seal?

[@jamespray]

The screw-together parts have mating sealing surfaces with a circular ridge on one face, designed to seal against a thin gasket (I used closed-cell packing foam sheet). I don't claim it's a perfect design (rather the opposite -- I should have used chamfered mating surfaces so neither would need supports), but I haven't noticed any leakage at these operating pressures. I did not put gaskets on the intake pipeline, which is probably why you can see the plastic sheet getting sucked into the joint below the intake stack right at the end :)

[@prozacgod]

If you're driving that thing between 10 and 15 volts, throw one of those 1 farad car audio capacitors on the power wires. I think that would work to get rid of the coil whine.

[@jamespray]

I'll be honest, after the adventures I've had with instant camera flash caps, a capacitor the size of a water bottle is terrifying!

[@prozacgod]

@@jamespray I mean... Don't lick it....

[@jamespray]

@@prozacgod sounds like a good way to lose a face LOL

[@warriorsabe1792]

If the motor's louder at low RPM, then what if you use some kind of drive belt so the motor can be at a higher speed than the compressor?

[@jamespray]

This does work, yes! It's actually already how I'm running it (1 to 1.5 reduction with a 6k RPM 775 motor). So if you only need low end, that is an option for doing it quietly.

[@mateijordache1952]

You should look into driving this with a BLDC using an FOC controller. Motor drive is quiet, low noise, high torque.

[@rajaspoorna6405]

Had never heard of FOC before! Thanks for this!

[@samk2407]

AHAH! YOU edit in DAVINCI RESOLVE I'd recognize that motion graphics title template anywhere! 5:58

[@jamespray]

lol, guilty! I'm sure this has "baby's first edited video" marks all over it

[@axeami1354]

you will probably see more successful pressure results if you make the second stage compressor smaller than the first stage .

[@jamespray]

I also suspect this, but this version doesn't make it easy/economical to test variations of the internal geometry. I hope to experiment with this in a future iteration that splits the housing into more pieces. Thanks!

[@JustAnotherBigby]

How much noise is the brushed motor? I wonder if a cheapo brushless and esc would reduce sound and power...

[@jamespray]

Up to a certain speed (not positive, maybe 1k RPM) the brushed motor is the noisy part :)

[@JustAnotherBigby]

That was sorta my guess. It does mean a brushless esc which may be a PITA. Regardless, great video.

[@jamespray]

@@JustAnotherBigby Thank you, appreciate it!

[@nickblacksoul4318]

Interesting,we have the same problems when making car compressor the electric ones , seems like a nice option

[@g45h96]

The main issue is finding something as efficient as traditional compressors. The parasitic losses of modern compressors are fractional compared to power gains under load. And it's self sustaining. The second issue is controlling the electric compressors in a meaningful way. The third issue is space. A DC motor hitting 10-20k rpm isn't super realistic in that environment. And anything stronger to run a reduction significantly increases size. But honestly, the biggest reason is just there's no demand for it. It's more than possible, there's just not enough of a market for any real pursuance.

[@nickblacksoul4318]

@@g45h96 when making these kind of turbo which are for few minutes boost ,efficient is not that important but running them with out a second battery that needs 48v because you need 30.000 rpm ,size maybe a problem but if you think that turbos need gases to work and compressors need belts it's will be easy install,plus getting them balanced is nightmare, believe metallic compressor get destroyed the same way ....

[@readdaily5680]

Will you do the design tutorial as well?

[@jamespray]

I'm not quite sure what you mean, but I'm not currently planning any new tutorials...

[@stefanguiton]

Great video! I had an Idea, why not use SimpleFOC to drive a large BLDC quietly Plenty of torque, you could easilly run this compressor or even use belts to increase or decrease the rpm if needed.

[@jamespray]

Pinned for the reference of any interested builders! I was initially dismissive of this idea, but after some thought, I think it might be the best way to open up the full range this design can offer. Having a cooling source that could run quietly for everyday use but also provide a wide range of extra cooling when desired was a big part of my overall goal for this, because currently I have to swap in different coolers for different power levels. You should try it! I will definitely keep it in mind if/when I get to working on the next iteration, it could just be a while :)

[@AKAtheA]

steppers utterly suck at torque *and* efficiency past a couple hundred RPM...this is a clear use case for a low Kv brushless direct drive with FOC to keep the noise down.

[@jamespray]

@@AKAtheA I'm a BLDC noob. If you have any suggestions for specific hardware, I'd be happy to take note for potential future testing!

[@AKAtheA]

@@jamespray BLDC is the same as a brushed motor, just the commutator is electronic (and can do regulation, since it already has the switching transistors), same principles apply... lots of wire turns on a pole = low speed, high torque. Few turns = speeed, but little torque."Kv" is just a ratio which tells you how much RPM you can expect for a given voltage on an unloaded motor.

[@jamespray]

@@AKAtheA Thx!

[@twinkbidlake1126]

Or you can get it by running the air through a tank of water it would gurgle then less you have an export valve that slows the decompression rate stabilizing it

[@thebowtieguy777]

this could be fairly easily designed to be infinitely stackable

[@jamespray]

In theory it already is. In practice I'd be worried about shaft alignment over maybe a 3-stack build. Of course, you can link multiple separate units to your heart's content :P

[@TengizAdamashvili]

omg I'm subscribing

[@jamespray]

🥳

[@antoniopacelli]

1:30..... .... Waghyu... that is the Original Concept for the Millennium Falcon... WhæWhæ

[@darkshadowsx5949]

how many would you need to put 175 psi into a small 5 gallon air tank?

[@jamespray]

I'm pretty sure the housings would deform and/or burst apart well below 175 PSI. It wasn't designed to handle that much pressure! If you machined it out of metal, then in theory the only limit would be how fast you could spin it. 10 stages at 50k RPM would probably generate a ton of pressure. In practice, though, this is the wrong design choice for filling air tanks -- that's a job for a low-flow, high-pressure pump. This is for applications that need a balance of mid flow and mid pressure and the ability to sustain it (instead of draining an air tank) -- think blow-off tools, remote cooling, bladeless fans, underwater air supplies, air hockey tables, etc.

[@claws61821]

​@@jamespray What about pairing it in front of or behind a HPLV design like you mention as consecutive stages? Would that offset the utility issue?

[@jamespray]

@@claws61821 Interesting idea. It might increase the fill speed of an HPLV setup if used as a booster, sure, though I'm not sure by how much!

[@tandr3w]

The first stage should be bigger than the second and so on. I would really like to see if it could be turned into a supercharger for an gas engine.

[@lokix_1607]

ooh a compressor

[@jamespray]

ikr 😆

[@avocadoarms358]

You know we all want to see how many CFM’s that big MF gonna kick out

[@kurtnelle]

would it be possible to put 1 compressor within another compressor (no brain, stop it). Or what about using an axial flux motor to decrease the motor noise (that's it I'm getting the vodka).

[@jamespray]

🤣

[@claws61821]

Lemme guess. The "yo dawg" meme? XD Depending upon the choice of design, yes, it is possible to nest concentric compressor assemblies. I don't know enough to say which designs work or if this is one of them.

[@kierancarter3693]

build a silencer box which it sits in

[@Quetzalcoatl0]

I'm searching for this, because i was thinking i could 3d print a turbo with an electric motor, to mimic some form of a turbo flutter, so play with, like a fitget spinner.

[@gadgetdeez7069]

Sounds like pancake motors and changing the frequency of your pwm would solve most of your issues.

[@fluffyluke9174]

try to make a two stage Centac compressor :D

[@jamespray]

Hmmm 🤔

[@46449771]

A brushless RC car motor would be quieter. Or perhaps an RC plane outrunner.

[@jamespray]

I'm sure you're right! Not to mention a fun way to explore the upper limits of performance. I'd like to pick one up eventually, but I'm thinking of playing with AC motors (e.g., salvaged from fans, vacuums, etc.) that I already have on hand, first. There's something to be said for not needing batteries or ESCs 😄

[@erlendse]

@@jamespray AC motors are brushed (whine) or limited to main frequency (mains Hz * 60 rpm). You can actually get 150/300V BLDC motors and BLDC controllers that runs from mains (110V / 230V), but the parts isn't as common as the lower voltage versions. a quite cheap secound hand server power supply can at least run 12V BLDC stuff (500W or more).

[@jamespray]

@@erlendse Server PSU is a good tip! I'll keep it in mind :)

[@michaeld954]

How fast can it inflate a air bed

[@jamespray]

Probably about 2 minutes for a twin size, but you'd want to be careful about when you stopped inflating ... 1 PSI above atmospheric pressure spread over the area of a twin mattress is probably about two tons of force on both top and bottom (based on napkin math for 84x48" surface area)

[@waldobean7534]

Here to see you blow up some more trash bags! Do it for the sea turtles. Those bags get what's coming to them!

[@jamespray]

More trash bag carnage coming soonish!

[@i_think_2_much277]

VORTEXESSSS! :)

[@wulfboy_95]

I wonder if an atomic pump could be built by stacking a lot of these compressors together. 🤔

[@jayalazuardi2407]

i wonder, if it could supply air to my moped lol

[@tahustvedt]

Did you see my 3D printed compressor that boosted my car? I on'y made the one proof of concept but it works.

[@jamespray]

I did see it

[@tahustvedt]

@@jamespray I'm hoping to find an old sports car to test more on and develop it more.

[@johnsmith-sp6yl]

your intro doesn't sound salty at all, in fact i couldn't hear a thing you were saying through that tin can with a string coming out of it jabroni microphone