And here I was just tonight playing with the idea of converting my squirt v2 into a push setup. May still do it just to see what happens, but will keep this data in the back of my mind as I test. Fantastic video!
@muteFPV Stock ones from Rotor Riot (thing:4580233). Very large gap between the duct and the blade so moving to a lighter design that allows me to use slightly larger props and _may_ help with air drag (thing:4483283). Debated using those larger ducts in pusher since the open sides will allow air to get sucked into the props and perhaps give some positive benefit.
I highly doubt the "open" design will have any performance benefits. Maybe it will be better to run simple prop guards instead of this one. I remember seeing a slimmer duct design for the Squirt that people said worked nice, but I can't remember the name.
If the duct shape is functioninal, which it probably is, by changing the propeller position inside of the duct, you might loose the advantage of it or even make it perform worse than without a duct, that's why i think the result differentiated this much.
Definitely unexpected results. Do you happen to have some feeler gauges to check whether the 3d printed duct actually has a smaller gap between the prop and the duct wall?
Just what I thought might be the explanation for this. The files for the printed ducts may be the same, but due to shrinkage the ducts became smaller. A manufacturer of injection molds usually designs those so that the final part has the right dimensions, +/- tolerance. In this scale, every 10th of a milimeter counts. In fact, to be efficient, proper ducts for the usual quad props would need to be less than half a mm from the duct walls, which is kinda hard to achive since all parts involved have lots of material related flex to them and manufacturing tolerances are all over the place, from an engineering perspective. After all, those are hobby, not "aerospace" parts :D I'd love to see a test done with oversize props ground or cut (lathe) down to precisely match the ducts. The props don't need the blade tip geometry which is designed to reduce vortices and all kinds of other phenomena at all when run in a duct anyway. :D Nice video anyway, thanks :)
Yep, the 3D printed ducts are uneven (not perfectly round) and some parts of the duct have a smaller distance between duct wall and prop tip, compared to other parts. I don't have feeler gauges handy but this is evident even with visual inspection. And this is what I am trying to point out with this video, because a lot of people think that converting to a pusher setup will always have a positive outcome no matter what. A whole set of duct tests has been on my to-do list for a very long time, I need to do it at some point.
No, it slots into the carbon frame parts only one way. But it is fairly symmetrical and this is one of the reasons why I chose this design for my example.
I'd like to see some pictures of how everything is being mounted in both configurations. The arm of the thrust stand will also interfere with airflow. Is thrust in the same direction relative to the stand for both the pusher and puller scenario? Regardless of the winner, the differences appear too large to be valid.
It is not a matter of who won, it is a matter of pointing out that there are a lot of parameters involved when choosing either setup and that one setup is not always superior to the other. I don't take photos of the setup, it is not part of my workflow. The thrust stands sits approx 150cm above the floor. The arm interferes with airflow in reality, why omit it in the tests? It exists in both push and pull configurations so it is considered a constant for these tests, not a variable. The thrust is not in the same direction relative to the stand but there is plenty of free space for air to flow in both directions. For more information you can read my detailed reply to the comment of user Francis. I stand behind my test results, which had been consistent throughout all the test runs. Please explain in more detail why you think they should be invalid.
@@muteFPV You sound like a guy who understands science so you probably also know that the results should be reproduceable by others. I'm looking to understand the method. My skepticism is from the degree of variance. I think there may be something else affecting the results and seeing the two setups might reveal that. Did you just flip the prop over and spin it the other way or did you change the mount? Was the arm in front of the airflow in one scenario and behind in the other? Are you comparing negative values on the strain gauge to positive values? Did you change the duct orientation? Setup photos would answer most of my questions. I see the great effort you put in and I appreciate it. I'll suggest that photo documentation of the setup should be part of your workflow if you want to make a scientific statement. No disrepect intended! I just like to know what I'm looking at when numbers are presented.
Just think of it this way: I did what you would do if you owned a Taycan and wanted to convert it to a pusher. The ducts don't fit to the frame upside down, they slot into the braces and rings only one-way. Also the ducts appear to have a very symmetrical design and it is one of the reasons why I chose the Taycan for this example. Of course the arms (of the thrust stand and of the frame) are in front of the airflow in one scenario and behind it in the other, how can it not be? The reason you are seeing such a difference in performance is because the propeller sits closer to the outlet of the duct in the pusher configuration. The difference would be even bigger if I had used the Gemfan 75mm 3-bladed props, whose prop tips sit lower than the hub (so they would be even closer to the outlet in push, compared to the D76 5-bladed). The goal of this video is to point out that there is a lot involved when chosing a ducted setup and that things are not just black or white. I am always including video footage of my tests. You can see that everything remains the same between push and pull, aside from the prop orientation of course.
It is necessary to compare without ducts. Here you can see the incorrect position of the propellers in the pushing mode. Can you do the same test, but with the same distance from the input and output to the propeller in both modes?
That could be a useful addition, although just for reference. Thank you for the suggestion. What do you mean by the second sentence? Incorrect position meaning that the position inside the duct is sub-optimal?
@@muteFPV distance from the input and output of ducts to the propeller is different for push and pull mode. Can you do the same test, but with the same distance from the input and output to the propeller in both modes?
That's true :P What do you prefer? I know that my muted videos are hard to follow in general buy I do like making them. A lot of people prefer talking though.
I don t know why my comment was remove but here it is again. Your test are misleading. You need to provide the gap information when testing different setup, also your push vs pull test can t be representative because when you do the pull test, your load cell is blocking some of the flow and create turbulance. The 3d printed duct will have a smaller gap for shure so better results. You can use recut propeller to match the gap of each test, that should give us a more realistic results. You still explain the propeller placement and that a good point but when you do the push vs pull, did you try to match the same placement??? I mostly do only thrust test with ducts on my thrust stand, if you want to contact me, I will be happy to discuss with you
Just to avoid any misunderstanding, I did not remove your original comment. Maybe it had a link in it and TH-cam removed it automatically, it happens quite often. I will reply to you in detail later today.
@@muteFPV I don t belive you remove my content, sorry if it sound so. I have made reference to another social media name. It is mostlikly, youtube algorymt that remove my post . . .
Yes, probably. I just wanted to make sure that there is no misunderstanding. The tests of this video are not meant to mislead anyone. There is no reason to mislead anyone with anything, so I suspect you may have missed the point of this video. The point I am trying to make is that there are situations where the pusher configuration does not perform better. Of course there is a specific set of parts that performs best for each duct and each configuration, but this was not the goal of this video. People usually just flip the parts around, convert from pull to push and call it a day, with the idea that one configuration is always better than the other. I was not trying to find the optimal / absolute best performance of these ducts or this motor-prop-duct combination. This was not the point of this video and this is why I did not trim larger props to barely fit them inside the ducts. I am testing the exact same motor, same propeller and same two ducts (one molded and one 3d-printed) in order to reduce variables and focus on the configuration and the duct material. The ducts are positioned with the stock stand-offs and carbon sandwich rings of the Taycan frame, so the alignment is the same between all the tests. I am giving data for push and pull performance on both molded and 3d-printed ducts. The 3D printed ducts have an uneven gap (smaller in some parts, same on other parts), which is one of the things I wanted to point out with this video. And this is why they happened to perform better. The push vs pull tests are, actually, representative because the mount and load cell are considered a part of the frame and, more importantly, they exist in both the push and the pull configurations (if the taycan carbon braces happened to be wider we would not even be talking about it, would we?). Please note that I am using custom CNC mounts so the width is not as wide as the stock motor mounts supplied by RCbenchmark. The width of the mount is almost the same as the width of the load cell. The mount and load cell are positioned behind one of the braces of the carbon frame. Both push and pull configurations are mounted the same way so this is not a variable, it is a constant that remains the same in both configurations during the tests. Same applies to the motor and propeller. The only variables are the configuration (push / pull) and the duct material (3d printed / molded). The reason I chose these parts is because they represent a very simple example of a BNF that was sold with 3D printed ducts, that several people had converted to a pusher setup and that has molded ducts as an upgrade part (and is sold with molded ducts in the more recent versions). So no custom solutions, just off-the shelf parts intended for the exact same quad. As for the placement of the propeller, again, the goal was not to find the optimal motor height / prop position for the maximum performance on these specific ducts. The goal was to simply prove that things are not always better when you choose a pusher setup. The prop was installed upside down, same way as anyone would install it when converting from pull to push. Feel free to send me anything you need, as a comment here or to my email (mutefpv at gmail dot com). I am always open to suggestions. I do want to dive more into duct experimentation, it has been in my long to-do list for a long time.
@@muteFPV tank you for the long reply. Yes I totally understand your point now that you want to narrow your experimentation on a spécific duct(drone) without changing too much variable. If I can add up too your test, your duct design look to have a open diffuseur because it is designed for the motor too be place at the bottom of the duct. A pusher design duct need to have a straigth or sligthly closed difuseur. On a design that I made for the shuriken-whoop 2.5inch, I saw a gain in thrust by choking the difuseur by 4%. When choking at 5% or 3% there where a lost in thrust. This duct have stator vane that also create additional thrust. 780 to 950g of thrust was easy to achive on this duct with a 2004 3000Kv to 3150Kv 6s. A 1505 3450kv was better on efficiency and thrust but the motor nearlly overheat on the thrust stand. I know it is hard work doing those tests, I have spend alot of time doing the same and trying to understand what happen everytime. If you keep posting video on duct design, I will recomand you to use a gage to mesure the gap and share this info on your video. My best gap that I was able to run test was 0.1mm. I saw a difference of near 100g of thrust between 0.1mm and 0.3mm on a 3 inch racewhoop (peak at around 880g on 4s). When I test small ducted drone with high rev motor, I often hit the rev limit on the software of my Rcbenchmark thrust stand so I found a small hack that can fix the rpm limit problem. If you are interested to know what it is, I will try to contact you and send you more info about it. Keep up your good work.
Thank you for the valuable information! I forgot to mention that the fact that the taycan duct is fairly symmetrical is another reason why I chose it for this specific video. I have some ideas regarding the test methodology of ducts for future tests, we can discuss further when it is time. What do you do for the rpm limit, play with the magnet count and then recalculate rpm afterwards? Which thrust stand are you using? I have switched to the 1585 for larger motors but their mount is too bulky for duct tests and I am not sure I can design a custom one without affecting their torque measurements.
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![[#2024MAMA] ROSÉ (로제), Bruno Mars - APT. | Mnet 241122 방송](http://i.ytimg.com/vi/dgGqD28J6aQ/mqdefault.jpg)
3:59 The propeller spins and my neighbors cry for mercy! 😂
True story 😜
And here I was just tonight playing with the idea of converting my squirt v2 into a push setup. May still do it just to see what happens, but will keep this data in the back of my mind as I test.
Fantastic video!
Thank you very much! Which ducts are you using for the Squirt?
@muteFPV Stock ones from Rotor Riot (thing:4580233). Very large gap between the duct and the blade so moving to a lighter design that allows me to use slightly larger props and _may_ help with air drag (thing:4483283). Debated using those larger ducts in pusher since the open sides will allow air to get sucked into the props and perhaps give some positive benefit.
I highly doubt the "open" design will have any performance benefits. Maybe it will be better to run simple prop guards instead of this one. I remember seeing a slimmer duct design for the Squirt that people said worked nice, but I can't remember the name.
@@muteFPV Nice thing is I can take a flush cutter to them if I decide I want open prop guards. ;)
The other one is called "slammed", I found it in my notes but I don't have any links to a design.
Fantastic testing, mate! Really well done! 😃
Pretty interesting results indeed! I wasn't expecting that!
Anyway, stay safe there with your family! 🖖😊
Thank you very much, you too mate!
So elaborated job máster 🙏👍
Thank you mate!
If the duct shape is functioninal, which it probably is, by changing the propeller position inside of the duct, you might loose the advantage of it or even make it perform worse than without a duct, that's why i think the result differentiated this much.
Definitely unexpected results. Do you happen to have some feeler gauges to check whether the 3d printed duct actually has a smaller gap between the prop and the duct wall?
Just what I thought might be the explanation for this. The files for the printed ducts may be the same, but due to shrinkage the ducts became smaller. A manufacturer of injection molds usually designs those so that the final part has the right dimensions, +/- tolerance. In this scale, every 10th of a milimeter counts. In fact, to be efficient, proper ducts for the usual quad props would need to be less than half a mm from the duct walls, which is kinda hard to achive since all parts involved have lots of material related flex to them and manufacturing tolerances are all over the place, from an engineering perspective. After all, those are hobby, not "aerospace" parts :D
I'd love to see a test done with oversize props ground or cut (lathe) down to precisely match the ducts. The props don't need the blade tip geometry which is designed to reduce vortices and all kinds of other phenomena at all when run in a duct anyway. :D
Nice video anyway, thanks :)
Yep, the 3D printed ducts are uneven (not perfectly round) and some parts of the duct have a smaller distance between duct wall and prop tip, compared to other parts. I don't have feeler gauges handy but this is evident even with visual inspection. And this is what I am trying to point out with this video, because a lot of people think that converting to a pusher setup will always have a positive outcome no matter what. A whole set of duct tests has been on my to-do list for a very long time, I need to do it at some point.
was duct flipped? cause is design to work one firection. Curious
No, it slots into the carbon frame parts only one way. But it is fairly symmetrical and this is one of the reasons why I chose this design for my example.
12:14 thank you for the amazing research.
You're welcome! I am happy you found the information useful!
I'd like to see some pictures of how everything is being mounted in both configurations. The arm of the thrust stand will also interfere with airflow. Is thrust in the same direction relative to the stand for both the pusher and puller scenario? Regardless of the winner, the differences appear too large to be valid.
It is not a matter of who won, it is a matter of pointing out that there are a lot of parameters involved when choosing either setup and that one setup is not always superior to the other. I don't take photos of the setup, it is not part of my workflow. The thrust stands sits approx 150cm above the floor. The arm interferes with airflow in reality, why omit it in the tests? It exists in both push and pull configurations so it is considered a constant for these tests, not a variable. The thrust is not in the same direction relative to the stand but there is plenty of free space for air to flow in both directions. For more information you can read my detailed reply to the comment of user Francis. I stand behind my test results, which had been consistent throughout all the test runs. Please explain in more detail why you think they should be invalid.
@@muteFPV You sound like a guy who understands science so you probably also know that the results should be reproduceable by others. I'm looking to understand the method. My skepticism is from the degree of variance. I think there may be something else affecting the results and seeing the two setups might reveal that. Did you just flip the prop over and spin it the other way or did you change the mount? Was the arm in front of the airflow in one scenario and behind in the other? Are you comparing negative values on the strain gauge to positive values? Did you change the duct orientation? Setup photos would answer most of my questions. I see the great effort you put in and I appreciate it. I'll suggest that photo documentation of the setup should be part of your workflow if you want to make a scientific statement. No disrepect intended! I just like to know what I'm looking at when numbers are presented.
Just think of it this way: I did what you would do if you owned a Taycan and wanted to convert it to a pusher. The ducts don't fit to the frame upside down, they slot into the braces and rings only one-way. Also the ducts appear to have a very symmetrical design and it is one of the reasons why I chose the Taycan for this example. Of course the arms (of the thrust stand and of the frame) are in front of the airflow in one scenario and behind it in the other, how can it not be? The reason you are seeing such a difference in performance is because the propeller sits closer to the outlet of the duct in the pusher configuration. The difference would be even bigger if I had used the Gemfan 75mm 3-bladed props, whose prop tips sit lower than the hub (so they would be even closer to the outlet in push, compared to the D76 5-bladed). The goal of this video is to point out that there is a lot involved when chosing a ducted setup and that things are not just black or white. I am always including video footage of my tests. You can see that everything remains the same between push and pull, aside from the prop orientation of course.
@@muteFPV I'm no closer to understanding what you've done but I can see this discussion has run its course.
I don't mind discussing further, by all means! Please let me know which part I have not explained adequately or is confusing to you.
It is necessary to compare without ducts. Here you can see the incorrect position of the propellers in the pushing mode. Can you do the same test, but with the same distance from the input and output to the propeller in both modes?
That could be a useful addition, although just for reference. Thank you for the suggestion. What do you mean by the second sentence? Incorrect position meaning that the position inside the duct is sub-optimal?
@@muteFPV distance from the input and output of ducts to the propeller is different for push and pull mode. Can you do the same test, but with the same distance from the input and output to the propeller in both modes?
I can and will, at some point, when I dive further into duct design. I have a few ideas that I think are interesting.
I don't understand the existence of the numbers to the right of the chart but other than that I appreciate the tests.
If you mean the comparison charts, there is a legend right next to the vertical axis, which says (for example) efficiency, current etc.
hi, good job Bro 😉🌈👍
Thank you!
this one not that "mute" 🤪
That's true :P What do you prefer? I know that my muted videos are hard to follow in general buy I do like making them. A lot of people prefer talking though.
@@muteFPV i like text and music better. more organized.
I am very happy to hear that!
I don t know why my comment was remove but here it is again.
Your test are misleading. You need to provide the gap information when testing different setup, also your push vs pull test can t be representative because when you do the pull test, your load cell is blocking some of the flow and create turbulance. The 3d printed duct will have a smaller gap for shure so better results. You can use recut propeller to match the gap of each test, that should give us a more realistic results. You still explain the propeller placement and that a good point but when you do the push vs pull, did you try to match the same placement??? I mostly do only thrust test with ducts on my thrust stand, if you want to contact me, I will be happy to discuss with you
Just to avoid any misunderstanding, I did not remove your original comment. Maybe it had a link in it and TH-cam removed it automatically, it happens quite often. I will reply to you in detail later today.
@@muteFPV I don t belive you remove my content, sorry if it sound so. I have made reference to another social media name. It is mostlikly, youtube algorymt that remove my post . . .
Yes, probably. I just wanted to make sure that there is no misunderstanding.
The tests of this video are not meant to mislead anyone. There is no reason to mislead anyone with anything, so I suspect you may have missed the point of this video. The point I am trying to make is that there are situations where the pusher configuration does not perform better. Of course there is a specific set of parts that performs best for each duct and each configuration, but this was not the goal of this video. People usually just flip the parts around, convert from pull to push and call it a day, with the idea that one configuration is always better than the other.
I was not trying to find the optimal / absolute best performance of these ducts or this motor-prop-duct combination. This was not the point of this video and this is why I did not trim larger props to barely fit them inside the ducts. I am testing the exact same motor, same propeller and same two ducts (one molded and one 3d-printed) in order to reduce variables and focus on the configuration and the duct material. The ducts are positioned with the stock stand-offs and carbon sandwich rings of the Taycan frame, so the alignment is the same between all the tests. I am giving data for push and pull performance on both molded and 3d-printed ducts.
The 3D printed ducts have an uneven gap (smaller in some parts, same on other parts), which is one of the things I wanted to point out with this video. And this is why they happened to perform better.
The push vs pull tests are, actually, representative because the mount and load cell are considered a part of the frame and, more importantly, they exist in both the push and the pull configurations (if the taycan carbon braces happened to be wider we would not even be talking about it, would we?). Please note that I am using custom CNC mounts so the width is not as wide as the stock motor mounts supplied by RCbenchmark. The width of the mount is almost the same as the width of the load cell. The mount and load cell are positioned behind one of the braces of the carbon frame. Both push and pull configurations are mounted the same way so this is not a variable, it is a constant that remains the same in both configurations during the tests. Same applies to the motor and propeller. The only variables are the configuration (push / pull) and the duct material (3d printed / molded).
The reason I chose these parts is because they represent a very simple example of a BNF that was sold with 3D printed ducts, that several people had converted to a pusher setup and that has molded ducts as an upgrade part (and is sold with molded ducts in the more recent versions). So no custom solutions, just off-the shelf parts intended for the exact same quad.
As for the placement of the propeller, again, the goal was not to find the optimal motor height / prop position for the maximum performance on these specific ducts. The goal was to simply prove that things are not always better when you choose a pusher setup. The prop was installed upside down, same way as anyone would install it when converting from pull to push.
Feel free to send me anything you need, as a comment here or to my email (mutefpv at gmail dot com). I am always open to suggestions. I do want to dive more into duct experimentation, it has been in my long to-do list for a long time.
@@muteFPV tank you for the long reply. Yes I totally understand your point now that you want to narrow your experimentation on a spécific duct(drone) without changing too much variable. If I can add up too your test, your duct design look to have a open diffuseur because it is designed for the motor too be place at the bottom of the duct. A pusher design duct need to have a straigth or sligthly closed difuseur. On a design that I made for the shuriken-whoop 2.5inch, I saw a gain in thrust by choking the difuseur by 4%. When choking at 5% or 3% there where a lost in thrust. This duct have stator vane that also create additional thrust. 780 to 950g of thrust was easy to achive on this duct with a 2004 3000Kv to 3150Kv 6s. A 1505 3450kv was better on efficiency and thrust but the motor nearlly overheat on the thrust stand.
I know it is hard work doing those tests, I have spend alot of time doing the same and trying to understand what happen everytime. If you keep posting video on duct design, I will recomand you to use a gage to mesure the gap and share this info on your video. My best gap that I was able to run test was 0.1mm. I saw a difference of near 100g of thrust between 0.1mm and 0.3mm on a 3 inch racewhoop (peak at around 880g on 4s).
When I test small ducted drone with high rev motor, I often hit the rev limit on the software of my Rcbenchmark thrust stand so I found a small hack that can fix the rpm limit problem. If you are interested to know what it is, I will try to contact you and send you more info about it.
Keep up your good work.
Thank you for the valuable information! I forgot to mention that the fact that the taycan duct is fairly symmetrical is another reason why I chose it for this specific video. I have some ideas regarding the test methodology of ducts for future tests, we can discuss further when it is time. What do you do for the rpm limit, play with the magnet count and then recalculate rpm afterwards?
Which thrust stand are you using? I have switched to the 1585 for larger motors but their mount is too bulky for duct tests and I am not sure I can design a custom one without affecting their torque measurements.