The Toroidal chape is a big dial when we are dealing with cavitation, because of the tip vortex. There is no tip. Its a revolution when we put in a maritime propeller, but we are dealing with a totally different mean. The water is 900x more dense, so it cavitates much more.
Yes, I definitely see how it is more effective in water than in the air, in the same way that regular boat propellers are shaped differently from ones for aeroplanes. In that regard it's interesting drawing the parallels there, and makes me wonder if there are general design rules going from boat to plane that could be applied to converting a Sharrow-style propeller to whatever its airborne equivalent might be. Another rabbit hole to dive into, haha.
kudos to you; this is the only fair comparison I've seen so far; I missed a side-by-side comparison of the two 3D printed ones but for anyone interested, they are in 3:574:15 there is a significant noise reduction, but definitely not enough to allow the design of viable commercial flying cars. however, as mentioned in the video, the toroidal propeller is way stronger than the regular one so that means that we can reduce the thickness/weight of the propellers which means faster and more efficient drones
I'm not sure if I did touch on that aspect yet, or not, but you're right, perhaps its inherent self-supporting nature could allow us to produce lighter-weight props compared to standard. This plus more conclusive testing in determining an ideal operating range might yet get us to a prop that's maybe more efficient than a "standard" design. Who knows...
Thank you for the inspiring videos, I will try to get my resin printer tuned and working. It has not printed in close to a year now, been busy with other parts of the hobby. But if I get it going, I will share if I find anything interesting!
I hope you pull it off! It's going to be about the right resin or resin mixture for you to be successful. I've seen a few people doing tests with resin and that is the biggest challenge, since the standard resins have a habit of exploding on spool-up. If you can get a print done and give it 100% throttle without a prop'splosion, write down that resin recipe!
@@STRIKINGFPV The community has been wanting a way to make resin prints stronger, forever now. Maybe this whole thing will lead to a small step forward, not only in FPV but resin printing materials, as well 🤞
@@Inertia888 Try adding about 25% Siriya tenacious into something like a blu or even just a standard ABS like, there are other engineering resin options that may be better but, they're like $100+ a bottle. I need to print some of these but, I've got so many projects going and I kinda hate using my resin printers.
Good job testing this and thank you for posting! Been testing your designs with a 4 inch micro apex and 2004 motors. Printed both 1st and 2nd versions of the bi and tri-blade design and changed into t-mount style. Had to cut 1mm of the height to accommodate for the shorter screws, used for normal props. Was able to get a decent print of the 1st version bi blades and was able to hover, but as soon as I throttled up all props exploded at the same time. (looked super cool btw). I was able to get a good print of the tri-blades and they did survive a little better, only one failed and did not completely explode like the bi-blade. Keep up the good work!
Is there video of the prop'splosion? It sounds somewhat heart-breaking but at the same time 4 props simultaneously exploding on throttle-up sounds exciting, haha. Glad you're also testing along with us, gives us a little bit of extra excitement in our flights, not knowing if a prop is about to split-apart 😅.
So very Interesting. After seeing this post, I was once again seriously wondering (briefly touched on this with you on a much earlier post) but now, I'd like to see if your STL file could be successfully converted to a STEP file to utilizing a 5 or 6 axis mill to create some from Lexan or even billet aluminum for testing. I've worked and worked and worked on trying to print a smoother 3.5" but since the loop goes shallower at the tip the printer even with different retraction speed/distance ETC leaves a dob-al of melted filament material creating a jagged serrated type edge when backtracking from the outer diameter back to the hub. Trying to correct that roughness post print creates a bit of out of balance and even a bit of unlevel blade tracking. I discovered the Polycarbonate with carbon fiber using #6 harden steel nozzle worked best for me in this matter. Recently, I've tried converting one of your STL files from Thingiverse to a STEP file. But the on line file converters for this task fail for me for some reason. In any event I'd truly like to see what a proper accurate CNC milled Lexan or aluminum Toroidal would actually do in AMPS & DB. Thanks again for your posts, so very impressive. Kindest Regards, Bob Griffith, Winter Haven, FL
My designs are available as STEP and also Fusion 360 files now, just head over to the V3 Tri-loop or V2 bi-loop and the STEP + F3D files are swimming amongst the STLs, so if someone does want to machine these with a 5 axis then that would be awesome. Just hope to see a video of that!
@@STRIKINGFPV thank you for the heads up. I’ll get the step file. I have just for fun/interest already placed an order for laser sintering of the 4” tri. Should be arriving 10th March. Set of 4 in laser sintered nylon Mater was $39.00 USD. I wanted to see if they could do them in Peek/CF sintered, but that was not on their current list. “ IF” I can find a party who’ll do a set on 5-axis for free or minimal amount, I’ll order a set just to see what they would truly do. Regards, Bob Griffith
thanks so much for doing a proper sound comparison! HUGE difference. It makes me much more confident to try out a toroidal prop on my Mini 3. I have a feeling that your drone being semi-ducted is actually a source of a lot of noise. It might be a lot quieter with fold up drones like the DJI Mini series Thanks again for your hard work man
I agree about the duct, which is why maybe testing on my Roma F6 would be better - but then the Roma I consider to be a "nicer" drone, would be a shame for it to suffer a crash from e'sploding propellers, lol.
@@STRIKINGFPV The duct is limiting the prop tip vortices same idea as the toroidal prop that's why they're quiter. You would probably notice a larger difference on an open prop.
Great test! I am an aerospace engineer, professional flight tester, and FPV/3D Printing enthusiast. So I plan to run with this once I get my printer rebuilt. I am interested in using vapor smoothing, as it is likely the most readily available technique to the average enthusiast. I would also be interested in your test setup (print settings, audio setup). That would be helpful for others to be able to replicate what you did. Typically I would ask about a lot more details like weights, battery health, weather, etc but I will document those details when I repeat the test. Also, you mentioned smoking motors, may I recommend you re-wind them? I have been re-winding 14XX and bigger motors for a few years with great results. Much cheaper and faster than ordering new. I can do one motor in about 30 minutes.
You know what, it's funny because I've rewound my motorbike's stator coil before - I actually converted it from single phase to three phase to generate more power. So in that regard yes, I would be able to rewind a motor - unfortunately the one that got burnt out is already a souvenir for my client from the shoot, haha.
IMO in addition to pitch and surface smoothness, the airfoil also matters a lot when designing a prop blade just like it matters when design airplane wings, otherwise we would be using just slight pitched flat boards on all the fixed wing RC planes. It might even matters more on a prop than on a wing, because the airspeed is much higher on the prop.
@@STRIKINGFPV uhh yeah exactly, don't step back, keep doing it it's so interesting : ) ok but if your 3d printer reached its max tech then at least make video updates on what other people have done and their specs. Thank you! You are so fun to watch!
You should do a laceration test on different surfaces similar to human skin. I feel like the real benefit of these props is safety. The goal is losing prop guards entirely and saving weight if possible for that sub250 category 1 class. Flight performance would be better all around as well.
G'day mate. Another pointer for you. Instead of deleting a body, click on remove. The not wanted parts will be deleted. So you don't need ro have the unused folder. Greg
Awesome editing. Made the A/Bing much cooler. I do agree about the resin printing. I don't have any quads, but printer(s). Aero things fascinate me, so this subject was an easy leap. p.s. you have the perfect voice for voiceovers. Incredibly wasy to listen to.
the way you edited the sounds, along with the spotlight of the current drone and prop being used was really creative! I was expecting to see at least a hundred thousand subs, hope you get there eventually but for now you just earned one more :)
Thank you for going this far with the research! Thank you for comparing it to the similar printed non-toroidal prop. Did exactly what a content creator should do which is everything we wish we could do and do all the work and edit it down being as amateur scientific method as possible. You’re right. Nothing conclusive but shows promise and potential. To the definitive result we were all hoping for but definitely interesting findings. Very good clean thought out work.
Thank you! I still like yours more, and the way you finished your props with the Dremel impressed me the most. I also have a Dremel but it's slowly dying, though somehow still rattles its way to high RPMs. I'm tempted to grab a fine sanding wheel and try smoothing my toroidals and regulars and try again, but it's very time consuming and I'll be traveling for work again soon. Maybe when I get back, would like to see if I can get closer to injection moulded quality and maybe reduce noise too.
this feels like a weird thing to take note of, but i really like the sound the loops make compared to the normal props, it feels wider, somehow, if that makes any sense, like the sound is coming from the profile of the entire ring instead of only the blade-tip.
The flexibility of your printed gem fan would've largely ruined its angle as it spun, which brings into question the efficiency comparison. But, that alone is a good argument to, if printing propellers at all, use toroidals.
Yes, that is my thought as well, since the toroidal rigidity is better. Interestingly, the blade tip angle of attack on the hex-blades wasn't as shallow as it would technically need to be since printing the overhang was more of a priority, so in a strange twist, there's a good chance the blade my have twisted forward slightly to the correct angle during flight, haha. Honestly I'm going to try printing those hex-blades again with varying thicknesses and materials to come up with a better performing one, probably upload it to Thingiverse and Printables for others to try. Won't be videoing this though, casual testing like I said. Of course, if the tweaked designs start to approach the efficiency of the toroidals, I'd have to make a follow-up and acknowledge that, because that could conflict with the loose conclusion to this video, haha.
If you want silent props, try the hqprop 89mmx8. Most quiet out of all. Ducts are loud too. Makes a hughe difference to non duct. Also you will have problems running 6 inch tri loop toroidal props on the roma f6. Basically that would be like taking a 6" six blade prop. That's over prop'ing your motors. They will spin, but totally not perform well
I'm not sure about that, I've noticed that more blades = higher pitch = more annoying, and videos I've seen of those HQ X8s does seem to suggest that. The funny thing about the MIT noise tests was the lower pitch whooshy sound being less annoying - maybe the X8s are quieter in terms of decibels, but I can't imagine they'll be any less noticeable. As for the F6, I do have to think about that. I do have the bi-loopdesign that I can go with, which would be running the equivalent of a quad-blade which is closer to the tri-blade I normally run, but I haven't touched the bi-loop design in a while and reports from some testers suggest that they need to be thicker to reduce flex at these big diameters, so I might end up doing a V3 bi-loop at some point. In theory the bi-loop is the better design anyway, so I might yet see better results with them than with the tri-loops.
But but but, warping! Also, the printer prints right next to me, and the fumes from both ABS and ASA are no bueno long term. I think I'll resort to sanding or varnishing to get a better finish for now, but yes, others may get decent results with acetone vapour baths. Back when I did print in ABS, years and years ago with the now-dead printer in my dad's old workshop, I did used to do the acetone vapour bath thing, but sometimes it got finicky and melty if you waited too long, haha. Also, smoothed everything but still ended up with the layer line texture, but instead of being able to like run your finger nail and hear it click, the vapour-smoothed prints would be smooth but feel ever-so-slightly wavy, haha.
Ahahaha yeah, actually I did want to do that but my Veyron's prop guards can't really be removed without somewhat compromising the structure - the base plate is attached by 2 long and thin standoffs plus the guards, so no guards means only the standoffs would be left and they're quite flimsy alone. If I did do the hot dog test, it would have to be with my Roma F6, but I dare say there's significantly more that can go wrong and I like my Roma, haha. Gotta think of the easiest way to do this, lol.
I can't quite see how that could be, I get that it probably doesn't "fling" air outwards as much as standard props, but the majority of air for generating thrust is still being pulled in by the area of low-pressure directly above the prop. I might be able to understand how the prop guard could be interfering with the loop edge somehow, but I don't think air is being pulled in from the side. Need to get someone running a CFD on this with and without ducts, lol
Check out Mark Rober video on Zipline. They have a drone with a new propeller design that is ultra quiet. There are two blades, but not at 180 degree, more like 60 degree and a weight on other side for balance. Zipline have not released any details, maybe proprietary
I still think a conventional propeller with uniform downwash distribution will give the best hover performance. Try a 1/radius taper to give a low tip vortex velocity. If you want the best then start with elliptical planform blade then scale with 1/radius. To get solidity ratio high enough for best lift to drag you will probably need 6 or more blades. Try 4 & 8 blades the do some excel curve fitting to spot the trend for best design solidity ratio.
All down to the resin or the resin mixture. Some people mix hard with flexible resins to try and get a balance between rigidity and flexibility - resins are typically brittle, so they hold shape very well but then will just snap under pressure, and so people who've been resin printing propellers will attest to very impressive and semi horrifying prop'splosions. The flexible resins, some claimed to be as flexible as TPU, obviously not ideal for props either, and so mixing resins is a thing.
Pity you feel you have used enough time on this for the moment, as you are leading the world (our little world) in this field. If you wanted to take one step further, you should try the same experiment without propeller guards (that probably mitigate the advantage of the toroidal propellers in terms of diminishing the vortices of the prop tips) and you should measure the noise spectrum with a phone app for a more appropiate comparaison. I would bet the thoroidal would outperform even more its equivalent 3d printed standard prop.
great videos on the topic, you will get some improvement on surface finish with SLS or other powderbed methods, but the surface finish still wont match injection molding ra 125 versus a ra ~32. I'd actually recommend using a resin printer to make a mold for injection molding the props. You'll only get a few runs from that mold, but should be enough to test to see if the difference in surface finish is causing the efficiency loss. Other option that people can try is using epoxy to cover the FDM blades to make a smoother surface finish. Use a small brush and try to fill between the layers. (Not that you will add some weight to the props.
Thats very nice idea of yours to print similiar regular prop and see that its actually that bad. Well still, MIT said they 3D printed it right? Maybe thats why they havent shown any serious data because their simulation shown excellent results but 3D printed prop was terrible :D THX for videos and your time
I not sure anymore - I've had a couple injection moulding guys say that it is possible, but I asked if they could have a look at my current designs to be sure and they haven't replied back. My big suspicion is that if the mould is to twist to release, the angle-of-attack would have to be absolutely perfect across the whole thing, you'd have to reduce the blade camber potentially, and then the intersection point between blades would be a complication too.
You can have a look at my other videos and you'll see exactly how, but long story short I designed these ones myself and I've made them available for everyone to try-out. We're of course limited by the nature of 3D-printing, but they do fly reasonably considering the very imperfect surface finish.
But if MIT hires you to build props for them, then you won't be able to share regular update and progress videos with us. Nice try... But I think once you see that CZcams adsense check for February you might change your mind, haha.
16A draw just to hover in place! Whoof. Certainly goes to show how much industry/university-grade optimization matters. People are dumping on the hobbyist-made, unsmoothed, flat cross section "MIT props" when comparing them to commercially-available, professionally-designed products with optimized blade geometry and injection moulded finishes, which is just silly.
I love this sort of testing but I can't take the background music. I jumped ahead to the flight test but when the background music came back on, stopped watching and came down here to express my frustration. I'm interested in this topic but it's just too annoying to try to listen to your voice with the background music fight for attention. Remember, we haven't heard what you're telling us. It's harder for us to understand what is being said than for you to understand what you said. I really hope you leave out the background music in the future. Even better would be upload a "music free" version of this video. Edit: This might be age related. I'm almost 60. I recall my father in-law having trouble understand human speech with background music. I didn't understand why background music bothered him so much until I aged a couple decades more myself.
Noted, sorry it was annoying for you. I had an earlier edit which excluding directly before and after the test flight, but it felt too empty to me so it was added. I'm also very careful with the background music, the levels are usually very low compared to my voice, and I also apply an EQ which greatly reduces the music volume around my vocal frequencies as well, to try and keep up the clarity, but evidently it's not quite good enough in your case. May I ask, how are you watching my videos? Laptop, desktop, TV, mobile, using decent speakers or just in-builts?
@@STRIKINGFPV I was using a cheap set of earbuds. They have an MPOW logo on the side. As I read my earlier comment, I'm embarrassed at how negative I was. I just watched a lot of the video using my speaker and the background sound is much less annoying. As I listen now (using speakers), I'm surprised I felt the need to complain about it. My cheap earbuds probably just boost the sound in the right/wrong way to sound bad to me. Sorry for coming across so negative. I love channels like yours which do these sorts of strange experiments.
Oh I've stated that numerous times in most of my toroidal videos, but if I didn't optimise for printability then I wouldn't be able to print anything to test, such is the world of prototyping 🤣
@STRIKINGFPV You keep talking about injection molding. So you are not going to try to get the current design molded right? And why don't you use a resin print service to try out the design that isn't optimized for printing?
Haha, well I'm a Hong-Kong-Australian who mostly grew up in Thailand and was affected by International Schools and a good amount of mostly American TV. My accent actually changes depending on who I talk to, but my "default" accent is mostly American-sounding with various words in English pronunciation.
The Toroidal chape is a big dial when we are dealing with cavitation, because of the tip vortex. There is no tip. Its a revolution when we put in a maritime propeller, but we are dealing with a totally different mean. The water is 900x more dense, so it cavitates much more.
Yes, I definitely see how it is more effective in water than in the air, in the same way that regular boat propellers are shaped differently from ones for aeroplanes. In that regard it's interesting drawing the parallels there, and makes me wonder if there are general design rules going from boat to plane that could be applied to converting a Sharrow-style propeller to whatever its airborne equivalent might be. Another rabbit hole to dive into, haha.
kudos to you; this is the only fair comparison I've seen so far; I missed a side-by-side comparison of the two 3D printed ones but for anyone interested, they are in 3:57 4:15
there is a significant noise reduction, but definitely not enough to allow the design of viable commercial flying cars. however, as mentioned in the video, the toroidal propeller is way stronger than the regular one so that means that we can reduce the thickness/weight of the propellers which means faster and more efficient drones
I'm not sure if I did touch on that aspect yet, or not, but you're right, perhaps its inherent self-supporting nature could allow us to produce lighter-weight props compared to standard. This plus more conclusive testing in determining an ideal operating range might yet get us to a prop that's maybe more efficient than a "standard" design. Who knows...
Interesting findings!! Looking forward to seeing those injection mold props beating the current props design!
Thank you for your work. You have shown me a different side of video creation. Like your style!
Thanks for your videos on this subject.
Thank you for the inspiring videos, I will try to get my resin printer tuned and working. It has not printed in close to a year now, been busy with other parts of the hobby. But if I get it going, I will share if I find anything interesting!
I hope you pull it off! It's going to be about the right resin or resin mixture for you to be successful. I've seen a few people doing tests with resin and that is the biggest challenge, since the standard resins have a habit of exploding on spool-up. If you can get a print done and give it 100% throttle without a prop'splosion, write down that resin recipe!
@@STRIKINGFPV The community has been wanting a way to make resin prints stronger, forever now. Maybe this whole thing will lead to a small step forward, not only in FPV but resin printing materials, as well 🤞
@@Inertia888 Try adding about 25% Siriya tenacious into something like a blu or even just a standard ABS like, there are other engineering resin options that may be better but, they're like $100+ a bottle. I need to print some of these but, I've got so many projects going and I kinda hate using my resin printers.
Another interesting video! Thanks for sharing. Cool JB gave you a mention
Cheers, glad you liked it. Did JB mention me recently, or you mean the video with Blunty from a few weeks ago now?
@@STRIKINGFPV I think it was from 2 weeks ago
Good job testing this and thank you for posting! Been testing your designs with a 4 inch micro apex and 2004 motors. Printed both 1st and 2nd versions of the bi and tri-blade design and changed into t-mount style. Had to cut 1mm of the height to accommodate for the shorter screws, used for normal props. Was able to get a decent print of the 1st version bi blades and was able to hover, but as soon as I throttled up all props exploded at the same time. (looked super cool btw). I was able to get a good print of the tri-blades and they did survive a little better, only one failed and did not completely explode like the bi-blade. Keep up the good work!
Is there video of the prop'splosion? It sounds somewhat heart-breaking but at the same time 4 props simultaneously exploding on throttle-up sounds exciting, haha. Glad you're also testing along with us, gives us a little bit of extra excitement in our flights, not knowing if a prop is about to split-apart 😅.
So very Interesting. After seeing this post, I was once again seriously wondering (briefly touched on this with you on a much earlier post) but now, I'd like to see if your STL file could be successfully converted to a STEP file to utilizing a 5 or 6 axis mill to create some from Lexan or even billet aluminum for testing. I've worked and worked and worked on trying to print a smoother 3.5" but since the loop goes shallower at the tip the printer even with different retraction speed/distance ETC leaves a dob-al of melted filament material creating a jagged serrated type edge when backtracking from the outer diameter back to the hub. Trying to correct that roughness post print creates a bit of out of balance and even a bit of unlevel blade tracking. I discovered the Polycarbonate with carbon fiber using #6 harden steel nozzle worked best for me in this matter. Recently, I've tried converting one of your STL files from Thingiverse to a STEP file. But the on line file converters for this task fail for me for some reason. In any event I'd truly like to see what a proper accurate CNC milled Lexan or aluminum Toroidal would actually do in AMPS & DB. Thanks again for your posts, so very impressive. Kindest Regards, Bob Griffith, Winter Haven, FL
My designs are available as STEP and also Fusion 360 files now, just head over to the V3 Tri-loop or V2 bi-loop and the STEP + F3D files are swimming amongst the STLs, so if someone does want to machine these with a 5 axis then that would be awesome. Just hope to see a video of that!
@@STRIKINGFPV thank you for the heads up. I’ll get the step file. I have just for fun/interest already placed an order for laser sintering of the 4” tri. Should be arriving 10th March. Set of 4 in laser sintered nylon Mater was $39.00 USD. I wanted to see if they could do them in Peek/CF sintered, but that was not on their current list. “ IF” I can find a party who’ll do a set on 5-axis for free or minimal amount, I’ll order a set just to see what they would truly do. Regards, Bob Griffith
Appreciate the way you demonstrated the testing. Very intelligent approach to the scientific method. Keep up the great work!
thanks so much for doing a proper sound comparison! HUGE difference. It makes me much more confident to try out a toroidal prop on my Mini 3.
I have a feeling that your drone being semi-ducted is actually a source of a lot of noise. It might be a lot quieter with fold up drones like the DJI Mini series
Thanks again for your hard work man
I agree about the duct, which is why maybe testing on my Roma F6 would be better - but then the Roma I consider to be a "nicer" drone, would be a shame for it to suffer a crash from e'sploding propellers, lol.
@@STRIKINGFPV The duct is limiting the prop tip vortices same idea as the toroidal prop that's why they're quiter. You would probably notice a larger difference on an open prop.
Great test! I am an aerospace engineer, professional flight tester, and FPV/3D Printing enthusiast. So I plan to run with this once I get my printer rebuilt. I am interested in using vapor smoothing, as it is likely the most readily available technique to the average enthusiast. I would also be interested in your test setup (print settings, audio setup). That would be helpful for others to be able to replicate what you did. Typically I would ask about a lot more details like weights, battery health, weather, etc but I will document those details when I repeat the test. Also, you mentioned smoking motors, may I recommend you re-wind them? I have been re-winding 14XX and bigger motors for a few years with great results. Much cheaper and faster than ordering new. I can do one motor in about 30 minutes.
You know what, it's funny because I've rewound my motorbike's stator coil before - I actually converted it from single phase to three phase to generate more power.
So in that regard yes, I would be able to rewind a motor - unfortunately the one that got burnt out is already a souvenir for my client from the shoot, haha.
IMO in addition to pitch and surface smoothness, the airfoil also matters a lot when designing a prop blade just like it matters when design airplane wings, otherwise we would be using just slight pitched flat boards on all the fixed wing RC planes. It might even matters more on a prop than on a wing, because the airspeed is much higher on the prop.
Make more videos on toroidal props! This is so interesting and cool!
Haha, just when I say I'll be stepping back for a bit and you're egging me on 😅
@@STRIKINGFPV uhh yeah exactly, don't step back, keep doing it it's so interesting : ) ok but if your 3d printer reached its max tech then at least make video updates on what other people have done and their specs. Thank you! You are so fun to watch!
You should do a laceration test on different surfaces similar to human skin. I feel like the real benefit of these props is safety. The goal is losing prop guards entirely and saving weight if possible for that sub250 category 1 class. Flight performance would be better all around as well.
G'day mate.
Another pointer for you.
Instead of deleting a body, click on remove.
The not wanted parts will be deleted. So you don't need ro have the unused folder.
Greg
Awesome editing. Made the A/Bing much cooler. I do agree about the resin printing. I don't have any quads, but printer(s). Aero things fascinate me, so this subject was an easy leap.
p.s. you have the perfect voice for voiceovers. Incredibly wasy to listen to.
the way you edited the sounds, along with the spotlight of the current drone and prop being used was really creative! I was expecting to see at least a hundred thousand subs, hope you get there eventually but for now you just earned one more :)
Kinder words have never been said, I will gladly accept your one more sub on my journey to (I wish) a hundred thousand, haha.
Thank you for going this far with the research! Thank you for comparing it to the similar printed non-toroidal prop. Did exactly what a content creator should do which is everything we wish we could do and do all the work and edit it down being as amateur scientific method as possible. You’re right. Nothing conclusive but shows promise and potential. To the definitive result we were all hoping for but definitely interesting findings. Very good clean thought out work.
in my book, that was really good testing! I eagerly await first injection moulded props!
Thank you! I still like yours more, and the way you finished your props with the Dremel impressed me the most. I also have a Dremel but it's slowly dying, though somehow still rattles its way to high RPMs. I'm tempted to grab a fine sanding wheel and try smoothing my toroidals and regulars and try again, but it's very time consuming and I'll be traveling for work again soon. Maybe when I get back, would like to see if I can get closer to injection moulded quality and maybe reduce noise too.
this feels like a weird thing to take note of, but i really like the sound the loops make compared to the normal props, it feels wider, somehow, if that makes any sense, like the sound is coming from the profile of the entire ring instead of only the blade-tip.
Very good 👍
Thank you! Cheers!
The flexibility of your printed gem fan would've largely ruined its angle as it spun, which brings into question the efficiency comparison. But, that alone is a good argument to, if printing propellers at all, use toroidals.
Yes, that is my thought as well, since the toroidal rigidity is better. Interestingly, the blade tip angle of attack on the hex-blades wasn't as shallow as it would technically need to be since printing the overhang was more of a priority, so in a strange twist, there's a good chance the blade my have twisted forward slightly to the correct angle during flight, haha.
Honestly I'm going to try printing those hex-blades again with varying thicknesses and materials to come up with a better performing one, probably upload it to Thingiverse and Printables for others to try. Won't be videoing this though, casual testing like I said.
Of course, if the tweaked designs start to approach the efficiency of the toroidals, I'd have to make a follow-up and acknowledge that, because that could conflict with the loose conclusion to this video, haha.
Rock on man love it🤘
love your editing. I know how incredibly taxing on your personal time it is. I'm going to sub just to support your endeavors 👍
see how much weight each will lift! Cool video!
If you want silent props, try the hqprop 89mmx8. Most quiet out of all. Ducts are loud too. Makes a hughe difference to non duct.
Also you will have problems running 6 inch tri loop toroidal props on the roma f6. Basically that would be like taking a 6" six blade prop. That's over prop'ing your motors. They will spin, but totally not perform well
I'm not sure about that, I've noticed that more blades = higher pitch = more annoying, and videos I've seen of those HQ X8s does seem to suggest that. The funny thing about the MIT noise tests was the lower pitch whooshy sound being less annoying - maybe the X8s are quieter in terms of decibels, but I can't imagine they'll be any less noticeable.
As for the F6, I do have to think about that. I do have the bi-loopdesign that I can go with, which would be running the equivalent of a quad-blade which is closer to the tri-blade I normally run, but I haven't touched the bi-loop design in a while and reports from some testers suggest that they need to be thicker to reduce flex at these big diameters, so I might end up doing a V3 bi-loop at some point.
In theory the bi-loop is the better design anyway, so I might yet see better results with them than with the tri-loops.
@@STRIKINGFPV czcams.com/video/UWoXFdRhPKc/video.html
Definitely believe the circular prop guards would reduce the advantages of toroidal loops.
What about printing with ABS or ASA then using Vapor smoothing with Acetone? Just an idea
But but but, warping! Also, the printer prints right next to me, and the fumes from both ABS and ASA are no bueno long term. I think I'll resort to sanding or varnishing to get a better finish for now, but yes, others may get decent results with acetone vapour baths.
Back when I did print in ABS, years and years ago with the now-dead printer in my dad's old workshop, I did used to do the acetone vapour bath thing, but sometimes it got finicky and melty if you waited too long, haha. Also, smoothed everything but still ended up with the layer line texture, but instead of being able to like run your finger nail and hear it click, the vapour-smoothed prints would be smooth but feel ever-so-slightly wavy, haha.
Maybe test to see if toroidal props are more or less damaging to a hot dog stuck in the props compared to regular designs.
Ahahaha yeah, actually I did want to do that but my Veyron's prop guards can't really be removed without somewhat compromising the structure - the base plate is attached by 2 long and thin standoffs plus the guards, so no guards means only the standoffs would be left and they're quite flimsy alone.
If I did do the hot dog test, it would have to be with my Roma F6, but I dare say there's significantly more that can go wrong and I like my Roma, haha.
Gotta think of the easiest way to do this, lol.
@@STRIKINGFPV strap the roma to a table and bring the hotdog in by hand... No danger to the quad
@@stocki_esy625 Ya'll really wanna' see some carnage 🤣
Nice video. And great editing. Still working on getting my resin printer acting right. But also spent a ton of time printing m2 screws,....
The toroid prop pulls air in from the side, therefore it is hindered by prop guards.
I can't quite see how that could be, I get that it probably doesn't "fling" air outwards as much as standard props, but the majority of air for generating thrust is still being pulled in by the area of low-pressure directly above the prop. I might be able to understand how the prop guard could be interfering with the loop edge somehow, but I don't think air is being pulled in from the side.
Need to get someone running a CFD on this with and without ducts, lol
@@STRIKINGFPV check the sharrow prop research....
Check out Mark Rober video on Zipline. They have a drone with a new propeller design that is ultra quiet. There are two blades, but not at 180 degree, more like 60 degree and a weight on other side for balance. Zipline have not released any details, maybe proprietary
I still think a conventional propeller with uniform downwash distribution will give the best hover performance. Try a 1/radius taper to give a low tip vortex velocity. If you want the best then start with elliptical planform blade then scale with 1/radius. To get solidity ratio high enough for best lift to drag you will probably need 6 or more blades. Try 4 & 8 blades the do some excel curve fitting to spot the trend for best design solidity ratio.
I know resin printing can be smoothed really well. Wonder if resin can hold together while spinning?
All down to the resin or the resin mixture. Some people mix hard with flexible resins to try and get a balance between rigidity and flexibility - resins are typically brittle, so they hold shape very well but then will just snap under pressure, and so people who've been resin printing propellers will attest to very impressive and semi horrifying prop'splosions. The flexible resins, some claimed to be as flexible as TPU, obviously not ideal for props either, and so mixing resins is a thing.
You’re videos are great! But for a fair comparison you should 3d print a 3blade and a 5blade with the same design concepts you did for the toroidal
Pity you feel you have used enough time on this for the moment, as you are leading the world (our little world) in this field.
If you wanted to take one step further, you should try the same experiment without propeller guards (that probably mitigate the advantage of the toroidal propellers in terms of diminishing the vortices of the prop tips) and you should measure the noise spectrum with a phone app for a more appropiate comparaison. I would bet the thoroidal would outperform even more its equivalent 3d printed standard prop.
10:21 lol
great videos on the topic, you will get some improvement on surface finish with SLS or other powderbed methods, but the surface finish still wont match injection molding ra 125 versus a ra ~32. I'd actually recommend using a resin printer to make a mold for injection molding the props. You'll only get a few runs from that mold, but should be enough to test to see if the difference in surface finish is causing the efficiency loss.
Other option that people can try is using epoxy to cover the FDM blades to make a smoother surface finish. Use a small brush and try to fill between the layers. (Not that you will add some weight to the props.
Thats very nice idea of yours to print similiar regular prop and see that its actually that bad. Well still, MIT said they 3D printed it right? Maybe thats why they havent shown any serious data because their simulation shown excellent results but 3D printed prop was terrible :D THX for videos and your time
Well next step: Build a mold. We all want to know. 😆
Why can't these be injection molded? Can't the mold twist apart and function?
I not sure anymore - I've had a couple injection moulding guys say that it is possible, but I asked if they could have a look at my current designs to be sure and they haven't replied back. My big suspicion is that if the mould is to twist to release, the angle-of-attack would have to be absolutely perfect across the whole thing, you'd have to reduce the blade camber potentially, and then the intersection point between blades would be a complication too.
Try making one for the fan behind you and see what can do?
Haha, actually had someone message me saying that they'd be trying to do that. I'd need a much bigger printer, haha 😅
Can you please upload the standard prop you designed to thingiverse to?
3d print all props without smoothing to compare unsmooth.
How is it that a patented propeller was made to be an open source? Where did you get the files?
You can have a look at my other videos and you'll see exactly how, but long story short I designed these ones myself and I've made them available for everyone to try-out. We're of course limited by the nature of 3D-printing, but they do fly reasonably considering the very imperfect surface finish.
But if MIT hires you to build props for them, then you won't be able to share regular update and progress videos with us. Nice try... But I think once you see that CZcams adsense check for February you might change your mind, haha.
The angle.of the toroidal blade is not correct
16A draw just to hover in place! Whoof. Certainly goes to show how much industry/university-grade optimization matters. People are dumping on the hobbyist-made, unsmoothed, flat cross section "MIT props" when comparing them to commercially-available, professionally-designed products with optimized blade geometry and injection moulded finishes, which is just silly.
I love this sort of testing but I can't take the background music. I jumped ahead to the flight test but when the background music came back on, stopped watching and came down here to express my frustration. I'm interested in this topic but it's just too annoying to try to listen to your voice with the background music fight for attention. Remember, we haven't heard what you're telling us. It's harder for us to understand what is being said than for you to understand what you said.
I really hope you leave out the background music in the future. Even better would be upload a "music free" version of this video.
Edit: This might be age related. I'm almost 60. I recall my father in-law having trouble understand human speech with background music. I didn't understand why background music bothered him so much until I aged a couple decades more myself.
I'm 20, bg music is not very annoying but is totally unnecessary
Noted, sorry it was annoying for you. I had an earlier edit which excluding directly before and after the test flight, but it felt too empty to me so it was added. I'm also very careful with the background music, the levels are usually very low compared to my voice, and I also apply an EQ which greatly reduces the music volume around my vocal frequencies as well, to try and keep up the clarity, but evidently it's not quite good enough in your case.
May I ask, how are you watching my videos? Laptop, desktop, TV, mobile, using decent speakers or just in-builts?
@@STRIKINGFPV I was using a cheap set of earbuds. They have an MPOW logo on the side.
As I read my earlier comment, I'm embarrassed at how negative I was.
I just watched a lot of the video using my speaker and the background sound is much less annoying. As I listen now (using speakers), I'm surprised I felt the need to complain about it. My cheap earbuds probably just boost the sound in the right/wrong way to sound bad to me.
Sorry for coming across so negative. I love channels like yours which do these sorts of strange experiments.
Loose the ducts and fly again!
Your design of experiments is slightly flawed. Your setup optimizes for printability and not for flight characteristics.
Oh I've stated that numerous times in most of my toroidal videos, but if I didn't optimise for printability then I wouldn't be able to print anything to test, such is the world of prototyping 🤣
@STRIKINGFPV You keep talking about injection molding. So you are not going to try to get the current design molded right? And why don't you use a resin print service to try out the design that isn't optimized for printing?
Where is your accent from? You sound like elon musk and I have no idea where that's from
Haha, well I'm a Hong-Kong-Australian who mostly grew up in Thailand and was affected by International Schools and a good amount of mostly American TV. My accent actually changes depending on who I talk to, but my "default" accent is mostly American-sounding with various words in English pronunciation.