Some interesting suggestions from both @DanielCrist and @ablightuponall, so my question to you all is, if we completely ignore the aerodynamic side of these counter-weighted props, are there any other factors to consider in balancing these other than achieving a centre-of-gravity on the axis of rotation?
Making the assumption that the toroidal loop and counter weight is balanced perfectly about the rotational axis and the centrifugal forces are balanced too. The only two other forces that can affect this balance of forces is drag and lift on either side which is difficult to achieve. Usually in aerodynamic design, we look at the main objective and then fix certain variables and alter the rest, otherwise it becomes an open ended equation.
@@qrious1797 It makes me wonder if a more effective asymmetric design would be to have differently shaped-blades which both theoretically generate the same lift and drag forces. But then the differently shaped blades would also generate a different wake for the next blade to have to contend with 😆. It's times like these that make me wish there were a user-friendly Windows-native open-source CFD program, but what's available seems to be Linux only. I've already had enough "fun" setting up Linux-based build environments for compiling microcontroller code 😬.
Sorry, I didn't see this, the tag didn't actually notify me. Unfortunately though figuring all of that out is starting to get into more intermediate physics which is beyond my knowledge. For example, it is possible that at higher RPMs, the mass which is further away from the center of rotation could increase the forces being exerted on the object, thereby changing it's relative center of gravity. That's what my intuition says, but I honestly don't know. This might be something to post in an engineering subreddit.
Or you could always have some fun and do an experiment, creating extremely large scale versions of this prop from foam (or some other cheap and easily shaped material) with various different counterweight designs, using an axel that is free to wiggle a little bit to see the results.
Very kind words, hope to make another video perhaps before my work really really begins, but would be less about propellers and more just general things about FPV. Cannot be a 3D printed propeller guy forever 😅.
I need to develop something with a weirder name I think. Absurdly Descriptive Titles for Obscure Engineering Prototype Concepts, or ADTOEPCs 😅. In my band we mash-up pop-songs and there's a trend in us making the mashed-up song titles as long as possible. Or at least that's what our bassist likes to do 😆.
I havent seen any "double" toroidals yet. Meaning Top and side profile. Harder to FDM print for sure. The noise would also be changed as I do think the outermost part would then become way more structural. Know anyone with a resin printer? Painting on the resin and using the sun to cure is another thought. Balance is another issue, then again, the orange peel effect might become more easily checked out practically. Not one negative comment on the slo mo footage, just as I thought. Very well done. I did notice the pixelation on the zoomed in shots, Cannot be avoided. Still cool AF. I am pretty sure that the original concept of these were tuned for the RPMs for which they were going to be used. CFD and FEI analyses and someone to properly interpret them would be highly beneficial.
Amazing video, I always love the homey feel your channel has! Something weird was happening with your voice audio every once and a while where it would get a little compressed and roboty. It wasn't detrimental to the video, but it did distract me every so often. Maybe take a look at how you're rendering your audio? Also, thanks for the cat! ♥
Good point on the audio - I didn't change how I did the audio compared to last time, but there is a slight quirk that DaVinci has with my audio process compared to Adobe Premeire, so I'll have to look into that. I actually use Adobe's AI voice enhancer which, for the most part, produces excellent results, but yeah something's iffy here. I'll see what I can do for the next video, whenever that happens 😅. Aside from that, glad you like the vibes! No doubt my cat has provided additional grounding in that regard, haha.
Just to confirm, while the water-submerged props have proven effective for boats at certain RPM ranges, we're still at ZERO toroidal prop designs/implementations in public space that show an a provable increase in efficiency for quadcopter flight, yes?
The only production toroidal propellers in existence, the Foxeer Donut, don't seem to have a significant benefit in terms of performance or sound signature over regular propellers at the moment. One can argue they behave like higher-pitched regular props and do have a slightly different sound, but the performance is still very comparable. The Sharrow propellers for use in marine applications, however, have significant performance benefits that have been tested and proven. I suspect it may stay this way for the foreseeable future unless someone comes up with a concrete design methodology that would likely have to link expected flight behaviour with efficiency targets and whatnot. We can liken how DJI Mavic drones have excellent flight time by basically being really gentle whilst they fly, so their prop size, pitch, shape and everything can be optimised for a relatively narrow operational window. Toroidals would likely be best-suited for that type of narrow operational window, but in FPV we can fly chill or aggressive so we're probably better-off with props that aren't super efficient at any speed, but perform pretty well across the entire motor RPM range.
OK. I'm at 3.00 and waiting... There's going to be distortion at high revs, stretching out the loop side and taking it out of balance, right? Now to watch the rest...
Could've watched 'till the end and still written this since I don't have a concrete way of knowing without maybe a very high-speed camera to watch for warpage. Either way, if this level of design is required to get a working lob-sided prop, having to adjust for warpage and proper CoG at an expected operating RPM, then I can safely say it's waaay beyond my capabilities 😅.
Just to comment on the beginning of the video, it seems you're not taking into account the centrifugal forces with the balancing. The counterweight might balance it while resting on an axis, but once that object begins rotating, the mass that is further away from the rotational point is going to create more force than mass rotating closer to the axis. You can see this if you rotate yourself in a desk chair and move your arms from being by your side to fully extended. If you just extend one arm you are still balanced in terms of glue much mass is on each half of your body, but you are no longer balanced in terms of the force being created by each half of your body. Unfortunately I don't have a solution for you, I'm just identifying a problem with the design. I should have said something in my comment on the previous video, but I was too distracted by the wiggly footage and the pretty yard.
Not sure if I'm following correctly - my understanding is that the centre-of-gravity is the point at which the object will naturally want to spin around, so the CoG as shown in Fusion 360 should be good enough, plus my post-print-painted adjustments. I've always thought the most major issue was the abnormal torque from having thrust/lift produced on one side, in the sense that the counter-weight side doesn't produce much (if any) lift and also doesn't undergo the same drag forces as the prop side does. I kind of postulate that, assuming balance is perfect, these abnormal lift/drag/torque forces are the next big challenge in which there may be a way to calculate blade loading, stretch and twisting torque in a way so that adjustments can be made to mitigate those issues. Unfortunately, I haven't seen many design resources, other than a Wikipedia article suggesting that mono-blades are not that efficient but simply exist to fit within certain design limitations (like making a stowable prop for a glider).
@@STRIKINGFPV Assuming a fixed RPM, the further out the mass, the more energy it has, since it is traveling a greater distance, proportional to the increase in orbital radius, like swinging a weight on a rope. So, to properly balance the counterweight, you have to increase its mass in proportion to the reduced distance from the axis of rotation, you can't just evenly distribute the mass across the two sides and call it good. Basically, you just want to beef up the outer edge of the counterweight a bit, make it chunkier, to compensate for the increased effective mass of the prop tips. Put as much of the counterweight mass away from the axis of rotation as you can. IIRC, the zipline wishbone props had little hammer looking protrusions at the end of their counterweights.
@@ablightuponall I think I get what you mean, it's an interesting notion but I'm not 100% on it. Need to think it through my head for a bit I think. If it's true though, I don't believe the hammer-like shape would be any more beneficial than the weird chunky blade I did. What I'd be interested in knowing is how much bigger I would have to make the counter-weight part in order to compensate for the opposite side. And does the extra mass or offset I need to achieve also depend on any other factors like expected RPM, for example?
Just fly the hqprop 89mmx8 and tell me how silent it is and how much thrust it has. It's got all you wanted from the toroidal props. I was disapointed by the foxeer donut. Thanks for testing all these options.
In general I've noticed that adding more blades generally makes the props louder, higher-pitched (in noise profile) and usually dragging more amps. Certainly seems to be the case when I switch from 3 blade to 5 blade, and from other prop comparisons online I've seen of those crazy 8 bladed props HQ made. What drone are you flying yours in, maybe you've got a config that works out better than others?
@@STRIKINGFPV I fly without ducts / guards. That makes it more silent. Also my experience is more blades is more silent. More pitch also more silent. It makes more thrust at lower RPM. You have to match with lower kv motors though. The props then spin slower causing less tip speed and noise. Just give the 89mmx8 a try and tell me they are more silent. Enough talk, more practical. Costs peanuts a set of props.
Some interesting suggestions from both @DanielCrist and @ablightuponall, so my question to you all is, if we completely ignore the aerodynamic side of these counter-weighted props, are there any other factors to consider in balancing these other than achieving a centre-of-gravity on the axis of rotation?
Making the assumption that the toroidal loop and counter weight is balanced perfectly about the rotational axis and the centrifugal forces are balanced too. The only two other forces that can affect this balance of forces is drag and lift on either side which is difficult to achieve. Usually in aerodynamic design, we look at the main objective and then fix certain variables and alter the rest, otherwise it becomes an open ended equation.
@@qrious1797 It makes me wonder if a more effective asymmetric design would be to have differently shaped-blades which both theoretically generate the same lift and drag forces. But then the differently shaped blades would also generate a different wake for the next blade to have to contend with 😆.
It's times like these that make me wish there were a user-friendly Windows-native open-source CFD program, but what's available seems to be Linux only. I've already had enough "fun" setting up Linux-based build environments for compiling microcontroller code 😬.
@@STRIKINGFPV czcams.com/video/UCeil8Zb_kw/video.html something like this on Xflow
Sorry, I didn't see this, the tag didn't actually notify me. Unfortunately though figuring all of that out is starting to get into more intermediate physics which is beyond my knowledge. For example, it is possible that at higher RPMs, the mass which is further away from the center of rotation could increase the forces being exerted on the object, thereby changing it's relative center of gravity. That's what my intuition says, but I honestly don't know. This might be something to post in an engineering subreddit.
Or you could always have some fun and do an experiment, creating extremely large scale versions of this prop from foam (or some other cheap and easily shaped material) with various different counterweight designs, using an axel that is free to wiggle a little bit to see the results.
I like this invention stuff. I'll support this
🙏Hooray, emotional support!
As always i could listen to you for hours. Thanks for your Video. More more more ;) all the best from germany.
Very kind words, hope to make another video perhaps before my work really really begins, but would be less about propellers and more just general things about FPV. Cannot be a 3D printed propeller guy forever 😅.
Although CWBLTP is pretty catchy, I recommend WST or Wet Swim Trunks. Thanks for the experiments and cat!
I need to develop something with a weirder name I think. Absurdly Descriptive Titles for Obscure Engineering Prototype Concepts, or ADTOEPCs 😅.
In my band we mash-up pop-songs and there's a trend in us making the mashed-up song titles as long as possible. Or at least that's what our bassist likes to do 😆.
I havent seen any "double" toroidals yet. Meaning Top and side profile. Harder to FDM print for sure. The noise would also be changed as I do think the outermost part would then become way more structural. Know anyone with a resin printer? Painting on the resin and using the sun to cure is another thought. Balance is another issue, then again, the orange peel effect might become more easily checked out practically.
Not one negative comment on the slo mo footage, just as I thought. Very well done. I did notice the pixelation on the zoomed in shots, Cannot be avoided. Still cool AF.
I am pretty sure that the original concept of these were tuned for the RPMs for which they were going to be used. CFD and FEI analyses and someone to properly interpret them would be highly beneficial.
good kitty
Amazing video, I always love the homey feel your channel has!
Something weird was happening with your voice audio every once and a while where it would get a little compressed and roboty. It wasn't detrimental to the video, but it did distract me every so often. Maybe take a look at how you're rendering your audio?
Also, thanks for the cat! ♥
Good point on the audio - I didn't change how I did the audio compared to last time, but there is a slight quirk that DaVinci has with my audio process compared to Adobe Premeire, so I'll have to look into that. I actually use Adobe's AI voice enhancer which, for the most part, produces excellent results, but yeah something's iffy here. I'll see what I can do for the next video, whenever that happens 😅.
Aside from that, glad you like the vibes! No doubt my cat has provided additional grounding in that regard, haha.
Just to confirm, while the water-submerged props have proven effective for boats at certain RPM ranges, we're still at ZERO toroidal prop designs/implementations in public space that show an a provable increase in efficiency for quadcopter flight, yes?
The only production toroidal propellers in existence, the Foxeer Donut, don't seem to have a significant benefit in terms of performance or sound signature over regular propellers at the moment. One can argue they behave like higher-pitched regular props and do have a slightly different sound, but the performance is still very comparable.
The Sharrow propellers for use in marine applications, however, have significant performance benefits that have been tested and proven. I suspect it may stay this way for the foreseeable future unless someone comes up with a concrete design methodology that would likely have to link expected flight behaviour with efficiency targets and whatnot.
We can liken how DJI Mavic drones have excellent flight time by basically being really gentle whilst they fly, so their prop size, pitch, shape and everything can be optimised for a relatively narrow operational window. Toroidals would likely be best-suited for that type of narrow operational window, but in FPV we can fly chill or aggressive so we're probably better-off with props that aren't super efficient at any speed, but perform pretty well across the entire motor RPM range.
OK. I'm at 3.00 and waiting... There's going to be distortion at high revs, stretching out the loop side and taking it out of balance, right? Now to watch the rest...
Could've watched 'till the end and still written this since I don't have a concrete way of knowing without maybe a very high-speed camera to watch for warpage. Either way, if this level of design is required to get a working lob-sided prop, having to adjust for warpage and proper CoG at an expected operating RPM, then I can safely say it's waaay beyond my capabilities 😅.
@@STRIKINGFPVI can speculate but I think the design is beyond me too😆
@@fluiditynz Good thoughts though, props there (pun intended?)
Just to comment on the beginning of the video, it seems you're not taking into account the centrifugal forces with the balancing. The counterweight might balance it while resting on an axis, but once that object begins rotating, the mass that is further away from the rotational point is going to create more force than mass rotating closer to the axis. You can see this if you rotate yourself in a desk chair and move your arms from being by your side to fully extended. If you just extend one arm you are still balanced in terms of glue much mass is on each half of your body, but you are no longer balanced in terms of the force being created by each half of your body.
Unfortunately I don't have a solution for you, I'm just identifying a problem with the design. I should have said something in my comment on the previous video, but I was too distracted by the wiggly footage and the pretty yard.
Not sure if I'm following correctly - my understanding is that the centre-of-gravity is the point at which the object will naturally want to spin around, so the CoG as shown in Fusion 360 should be good enough, plus my post-print-painted adjustments.
I've always thought the most major issue was the abnormal torque from having thrust/lift produced on one side, in the sense that the counter-weight side doesn't produce much (if any) lift and also doesn't undergo the same drag forces as the prop side does. I kind of postulate that, assuming balance is perfect, these abnormal lift/drag/torque forces are the next big challenge in which there may be a way to calculate blade loading, stretch and twisting torque in a way so that adjustments can be made to mitigate those issues.
Unfortunately, I haven't seen many design resources, other than a Wikipedia article suggesting that mono-blades are not that efficient but simply exist to fit within certain design limitations (like making a stowable prop for a glider).
@@STRIKINGFPV Assuming a fixed RPM, the further out the mass, the more energy it has, since it is traveling a greater distance, proportional to the increase in orbital radius, like swinging a weight on a rope. So, to properly balance the counterweight, you have to increase its mass in proportion to the reduced distance from the axis of rotation, you can't just evenly distribute the mass across the two sides and call it good.
Basically, you just want to beef up the outer edge of the counterweight a bit, make it chunkier, to compensate for the increased effective mass of the prop tips. Put as much of the counterweight mass away from the axis of rotation as you can. IIRC, the zipline wishbone props had little hammer looking protrusions at the end of their counterweights.
@@ablightuponall I think I get what you mean, it's an interesting notion but I'm not 100% on it. Need to think it through my head for a bit I think. If it's true though, I don't believe the hammer-like shape would be any more beneficial than the weird chunky blade I did. What I'd be interested in knowing is how much bigger I would have to make the counter-weight part in order to compensate for the opposite side.
And does the extra mass or offset I need to achieve also depend on any other factors like expected RPM, for example?
What about the Zipline tri props?
Lovely cat. xx
Just fly the hqprop 89mmx8 and tell me how silent it is and how much thrust it has.
It's got all you wanted from the toroidal props. I was disapointed by the foxeer donut.
Thanks for testing all these options.
In general I've noticed that adding more blades generally makes the props louder, higher-pitched (in noise profile) and usually dragging more amps. Certainly seems to be the case when I switch from 3 blade to 5 blade, and from other prop comparisons online I've seen of those crazy 8 bladed props HQ made. What drone are you flying yours in, maybe you've got a config that works out better than others?
@@STRIKINGFPV I fly without ducts / guards. That makes it more silent. Also my experience is more blades is more silent. More pitch also more silent. It makes more thrust at lower RPM. You have to match with lower kv motors though. The props then spin slower causing less tip speed and noise.
Just give the 89mmx8 a try and tell me they are more silent. Enough talk, more practical. Costs peanuts a set of props.
Lovely fat cat 😆