Cine-Whoop! or Cine-Whoopsie? Testing 3 - 3.5" Ducted Props

[@gimbalair]

Chris, insightful as always, I understand some stuff and you debunk the techy stuff with bar charts, that works for me. Your motors vid was great too, just cannot find the Shysters anyway on the planet!

[@lorinwingtips5290]

YAY! Awesome as always! I'm curious how the HQ 90mm 8 blade stacks up in testing to a 5" prop. I've been using them on my AOS 5" UL for a while to fly in places where the noise of a screaming 5" might be disruptive. While they certainly aren't as efficient, i've not felt i was lacking thrust over a 5" tri-blade, and they certainly seem much quieter. Of course, none of that is Science, just my impression when using them. :D

[@davet2563]

I have been using them as well, they are way smoother than my regular tri-blades, and my blackbox records less noise when using them. I am curious about what sample size was used when doing the vibrational testing.

[@TheTomJon]

Another banger video chris thank you

[@prostheticconscience6707]

i’d really like to see open-air props from previous video directly compared (using the same motor) to the ducted fans

[@BlackBirdFPV]

Iflight nazgul are by far the best for whoop. You should try them

[@funkynerd_com]

And of course, the 2 cinewhoop props I run are not tested. The HQProp D90x3 and HQProp D90x5. I feel like the D90x5 is one of the most efficient props I use, but it would have been nice to see hard data on that. I guess I can infer that from the data from the T90x3 and Gemfan 76x5? Maybe?

[@alainassaf]

those 8 blades are super fun on a 5" quad with 4S motors and a 6S lipo !! you lose in efficiency but the sound is awesome and the speed is not bad at all.

[@chrisbee5481]

Try the hq 4x4x6 on a 5" quad. Awesome fun too.

[@JochenSchurich]

Hi Chris! Great video, thank you so much! I'm quite surprised with the outcome: after watching this video (using these ducted props as open props) and compare it with your "Open Prop Testing" video it seems that the ducted props are more efficient and produce more thrust. e.g. the HQ-90MMX3 as open prop beats the Avan Scimitar 3.5x2.8x3 in thrust and efficiency!

[@MCsCreations]

Fascinating finds, Chris! Fantastic testing!!! 😃 Stay safe there with your family! 🖖😊

[@ChrisParayno]

Great work Chris! As a person whose done duct design work, a large impact of designing proper ducts is the gap between duct and fan. You hit the nail in the coffin by stating that open air prop guards are much actual better "ducts". Keep up the great work.

[@loydsa]

Hi Chris, it would be interesting to see the comparison between your straight ducts and "normal" (by normal I mean what is used on full sized ducted fans with bell mouths exploiting the coanda effect)? Best regards Sarah

[@josiahmos5880]

Now I'm curious how much effect a smaller prop guard will have.. Thanks for your great videos

[@LoneStarUAV]

Unfortunately, this is missing the Gemfan D90-5, I really wanted to see how it compares to the HQ 89-8

[@aphinion]

Your measurements explain quite a lot what I got as a result in real life: My Beta FPV 95x gets only about half the flight time than my Cine25 despite having smaller props... but they basically run freely. It also feels better in flying and makes significantly less noise - both in volume and in subjective feel.

[@neilfpv]

Great video! My experiment from last year is the same as what you've discussed. That's why I got rid of the duct. It makes the flight really bad.

[@impuls60]

The duct lip (which yours havent got) is the source to an possible increase in lift. The lip works as a wing airfoil when properly implemented. Excellent video and sum up!

[@YorkyPoo_UAV]

Yea those printed ducts he had only adds weight and blocks air flow. You need something like the Terraplane for puller or Avata for pusher duct style. My 3.5" Terraplane can get 8-10 min flight with a 1800mah battery and it feels like it's on rails.

[@ChrisParayno]

The issue with duct lips, is that you're assuming laminar flow entering the duct and even distribution on the fan surface. In reality, the way quads fly with ducts they are flying at a less than ideal angle of attack and very uneven distribution of flow as it enters the ducts. It's much more complicated then just sucking air into the duct. This is why he recommends open air or prop guards over ducts.

[@CiottiFPV]

I can't help but wonder if the ducted setup would do better as a puller, can you spin the motor/prop the opposite direction to test that?

[@FL_Engineer]

That was referenced in the first video. He feels like the dirty air from the test stand impacts the results.

[@CiottiFPV]

@@FL_Engineer that makes my question even more interesting though, will there be a different impact from all of that dirty air on the pulling vs pushing side of the thrust

[@chrisbee5481]

Exactly. Just test one a puller vs pusher and compare the results

[@luis_gbs]

@CiottiFPV, don’t you fly the FpvCycle Toothfairy2 as well? I would love to know if you think I am mistaking, but I feel it flies so good and I wouldn’t want to miss the ducts because they give a flight feel I never had on any open prop quad… @Chris, would you mind doing some tests with ducts like them,it would be verrrry interesting as they are similar to slammed ducts and the blade sits damn high in the duct.

[@CiottiFPV]

@@luis_gbs yeah one of my cinewhoops is a toothfairy 2, flies the same as the cinesplores but is a bit lighter, ducted flight characteristics are basically just slower with less sideways slide making shooting gaps and being pin point accurate much easier

[@gimbalair]

Great video Chris.

[@MasonJarMassey]

I’m glad I found your channel now but damn if only I had seen this before guessing on props for my CineBot…

[@keenheat3335]

perhaps plot the thrust vs rpm graph in a log scale instead of linear scale. So it's easier to see the cross over points between different prop designs.

[@hu5116]

Interesting about the duct design. So what it means is that the duct was not designed properly. Instead, the duct needs to start only at the tip of the blades. It would be good to see a retest with a redesigned duct.

[@3n204]

Well, love the video but i have a question regarding the ducts. The Bumblebee is not a pusher cinewhoop and the prop is pretty far up. I think there are some other people too, that fly a puller-cinewhoop. I would have loved to see a test for that too.

[@AmitLeibov]

So Chris, what props are recommended overall for cinematic cruise , fully ducted or inducted, with AOS cine35 which is quite a heavy build, even with O3 setup only. ? Thank you for all the content 🙏🏻

[@davet2563]

Curious about what you said about auditory noise, HQ x8 props are some of the quietest sounding props I have flown on my 5-inch without ducts. The moment you put them in ducts they scream though.

[@tomengman]

I run the Gemfan D76-5 without ducts on a little 3" i cut from leftover carbon sheets, man that prop does some interesting things when ran without ducts, I'm getting close to 5 minutes flight time with a full size hero 8 on it and a 850mAh 4S. It honestly surprised the hell out of me, because it really feels quick and responsive even with the insane overweight. Probably shouldn't talk about durability when ran without ducts though..

[@BabyKnxckz]

Idk how ducks exactly work but i imagine if you design them so they dont go that far over the prop where it would suck the air in they may still give a boost

[@villadante]

Thank you

[@billmcdonald4335]

As far as my experience goes, this should hold for 2-inch props, too. I've tried a couple of tri-blades [LDARC/KK 1935 {absolute crap}, HQ T2x2.5x3 {better, but still crap}], and a quad blade [LDARC/KK 2045 {kind of okay}], before landing on Gemfan D51s {perfection}. That design fits my LDARC/KK 1103 7800 kV motors and LDARC/KK 1.9" prop guards like it was meant to be there, delivering true duct performance. The blades are quiet and efficient; smack dab middling in performance - not too fast, and good with propwash.

[@HansBaier]

Excellent!

[@TeeDubzz]

You tend to get better low-pressure thrust without a duct and better high-pressure thrust with one; the issue you are seeing here is you're comparing *static test values*, unducted props have good static thrust but lower high-end thrust, and ducted props generally have poor static thrust but better high-end thrust.

[@kf4293]

Curious what motor people are running with the 76 5 blade?

[@ExplorewithZac]

Okay so what about prop guards right at the edge of the props?

[@ChrisRosser]

I mean theoretically it should help if you can get small enough gaps but no-one can get tight enough tolerances on plastic props and 3D printed ducts at these sizes to actually achieve any benefit, even in theory, let alone in practice.

[@tobluskis]

Where’s the first video?

[@johnnyjohnson6771]

oh, and why don't you streamline the duct struts too.

[@christopherconkright1317]

I think this is why all the new ducted drones have slits or air holes in the ducts

[@ryanokeefe12]

It would be interesting if you tested a proper duct with a flared opening and non pusher configuration... I've been trying to explain how inefficient moving to pusher and removing the flare on the duct actually is. Sure, pushers have an unobstructed column of air but they're receiving turbulent air to the prop itself.. The prop and motor will be impacted by this. in a standard configuration, the motor gets clean and unobstructed air.. it doesn't care what happens after it (within reason). The flare is one of the major contributors to lift/thrust for a ducted setup as well. the flare should start just above the prop which allows for the prop to achieve the same surrounding air intake that you speak of whilst avoiding losses due to tip vortices

[@ChrisRosser]

In my testing pusher props are significantly more efficient than puller props for open configuration s. The difference is around %10 or so for a typical arm. The air being drawn into the prop comes from a wider area than the thrust column so I suspect that's why blocking the inlet is not such a big deal as blocking the outlet. If you add a duct then the effect of blocking inlet or outlet is the same as we would expect.

[@secondnotion9506]

Ever since i tried gemfan 5 blades ive never went back to 3 blades for any of my cinewhoops. Flying indoors my cinelog35 felt heavy, sluggish and flew shorter with 3blades carrying 1500mah and full go pro. But with 5 blades it just flies better and much more efficient and even more efficient if you go lower kv. And theres barely any difference flying indoors or outdoors. I get 12mins of flight time no gp 1500mah and 10.5mins with full gp same batt

[@StarsAtNight1]

Nice test. Wished you tested the 4 inch props, because that is like the max size to build when we need to keep it under the 250g law.

[@cch201992]

I was saying this before I like the gemfam 5 blades the shape of the blades I feel is more efficient and quieter to my ear anyway 🤷🏻‍♂️ I was running some on my rekon35 switched to the gemfan 3 bade because like you said normally more blades are less efficient but now I might go back to the 5 blade given your data because I feel the 5 blade was quieter 🍻

[@chrisbee5481]

Rekon35 on 2S with those gemfan props? Thats over prop'n the 1303.5 motors. Might work somehow and be quiet.

[@cch201992]

@@chrisbee5481 oh it did work and it was super quiet I loved it

[@chrisbee5481]

@@cch201992 try the HQ 75mmx5 props. I'm sure you will like them more than the gemfan 5 blade for the rekon35. Also the DT76mmx4. All super quiet and not as heavy and hardcore pitched like the gemfan.

[@johnnyjohnson6771]

your duct design is flawed with it's sharp cornered and non laterally transitioned inlet not to mention the duct makes the inherent air blockage of your test stand even worse. I think you need to redesign the duct shape and use a 2-3 inch standoff behind the motor in order to get better airflow into the duct. You might even put a shroud on the stand elements in order to smooth airflow. Your effort is to be applauded but this test needs a redo.....

[@hu5116]

It would really have been good to start out showing what these props. look like! All is see is nomenclature gibberish, which does almost nothing to understanding what is going on.

[@davidhayter6804]

Youre opinion and findings about the ducts efficiency doesnt explain why the dji at 410g with ducts have 13 to 15min flight time compared to a caged 3 inch cinewhoop that weighs 410grams but doesnt get close to 10 to 15 mins. Imo opinion, youre duct design is very poor and does not compare to the design efficiency of modern cinewhoops with ducts

[@ChrisRosser]

The main difference between FPV quads and DJI quads is that DJI is using Li-Ion batteries which have lower power output but more energy density. If you compare an FPV quad with a Li-Ion pack to a DJI quad at the same weight the FPV quad will get similar flight time.

[@secondnotion9506]

Chris the duct you used here are one of the worst designs, modern pusher cinewhoops have better design which makes them super efficient, one of the best example is the oddityrc25 probably the best 2.5inch frame out there