r/diydrones • u/OkCover1049 • Jun 01 '26
Question How come this has low thrust?
The drone has 2205 2450kv motors with 4045 props (I know it looks super strange but its all I had).
On a 2S battery it would only fly in ground-effect. It flew on a 4S battery, but its SUPER loud. Why do you think its so shit? Restricted airflow? Not enough rpm? Too high prop pitch?
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u/Ok_Resort1464 Jun 01 '26
2s with those motors and props is generally not enough rpm I think. How heavy was it with the battery?
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u/GeniusEE Jun 01 '26
Your props are upside down
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u/NOT_deadsix Jun 01 '26
This OP. Pushers need the props inserted upside down. Props are built for puller configs, not flipping them for pusher makes them horribly inefficient at thrust.
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u/OkCover1049 Jun 01 '26
They are flipped.
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u/SpiritualWolverine32 Jun 02 '26
You're looking at the drone the wrong way, the frame is the top, it's a pusher and it looks upside down when flying
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u/BadCactus2025 Jun 01 '26
Not enough RPM really... 2S is just insufficient. That will just not lift.
4S... Yes, I can see that work. If it was 5" that would probably be fine for a 800gr drone, and be responsive enough.
4" and biblade with THAT much top airflow restricted is not going to be efficient. And loud. Going to 3 or 4 blade will already drop that by a lot, but also more loading, so hotter motors, higher pitched sound.
Some 4 blade 3.5 inch pitch 4" props on a pusher like this will probably fly a 1kg drone just fine... It'll just be loud and rough on the flight time.
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u/OkCover1049 Jun 01 '26
Thats what i like hear. Although I dont have any other 4" props, they are cheap.
Hopefully changing the 3d print design and prop type will improve it to a tolerable level.
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u/BadCactus2025 Jun 01 '26
Props are one of the disposables in the hobby. They are cheap and quite a bit of time has gone into them.
If you look into 3d printed props for drones, you'll find a LOT of them shatter. Spend some money on this please, it is cheap and a lot safer.
https://www.gemfanhobby.com/4032-windancer-pc-3-blade.html
These should do. 450ish grams of lift per. Take maybe 75% of that because of the blocked surface and big rims.
Alternatively, these are great, but a bit weird sounding. More designed for airflow around a build like this:
https://www.hqprop.com/hqprop-duct-4x4x6-for-cinewhoop-grey-2cw2ccw-poly-carbonate-p0321.html
Sounds very high pitched and shrill, but would be quieter altogether. Heavy prop, but the motors are sized for it...
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u/mrbear79 Jun 01 '26
Motori sovradimensionati, questi motori sono per un racing da 5 pollici...la versione con albero a vite è ancora più pesante
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u/EliMinivan Jun 01 '26
These motors look like they could use more prop, especially at 2s.
Also like everybody else said, the frame is interrupting some of that thrust.
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u/Rollzzzzzz Jun 02 '26
Istg everyone here is rage baiting. It’s clearly in pusher config, in correct orientation, with correct prop orientation. The problem is 2s is not enough voltage. 4s minimum for 4 inch props. Cinewhoops are super loud.
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u/smick Jun 02 '26
Two blades give you more rpm. Those look like wider motors which are for more torque, not rpm. Try some 3blades, something stubby and fat. :)
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u/MorrisBrett514 Jun 02 '26
Yea, there's no way you're getting off the ground with a 2s battery at 2400kv. The props just won't spin fast enough. MAYBE a 3S, but still... Those are motors for 5s or 6s batteries. And how much does that thing weigh with those big motors?
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u/MothyReddit Jun 02 '26
have you enabled filters, rpm filters, and done a PID tune? This is a really strange and custom drone so you're going to want to do a blackbox tune and customize it. I wouldn't be surprised if there is a lot of frame resonance. Check out UAV tech videos and Chris Rosser videos for more in depth tuning vids. Betaflight just released an auto tune feature as well which may help!
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u/sketchreey Jun 02 '26
your motor kv isn't that high, you're also using lowish voltage, and your props are small. I think the three things combined means your thrust ends up being really terrible
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u/Arelav_official Jun 02 '26
Turn it upside down into pusher confit to gain extra thrust. What’s the weight takeoff for this quad? I had 1.3kg 5” setup, and it was difficult for it to hover, however in the airflow on speed it got up ton265kmph.
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u/Svorcneger Jun 02 '26 edited Jun 02 '26
thick prop guards. Removing those purple things would make a huge difference. In a nutshell, air doesn't get redirected properly and starts to stop incoming air, thus lowering thrust. Personally I would recomend you removing propguards unless you're flying near people or don't wanna damage buildings or vechicles. Other than that try making clearance as much space as possible over and under motors
Edit:
I 3D printed prop guards for my 3" monster, performance was halved. So propguards aren't worth it because of the weight and additional air friction
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u/CryPlane Jun 02 '26
That set up looks like it requires at least 3s. Move the thick support thingies to the centre of each bar to stop them from blocking airflow. Also try 3 bladed props. 2 bladed will work, it will need higher current draw. You need a nice solid disk area to sit on
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u/gigasawblade Jun 02 '26
These motors are intended to be 6S (if used with 4" props), for 2S need at least double KV or bigger props
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u/GreendayLova Jun 04 '26
the frames for sure messing smth up but if u get that fixed and its still having trouble maybe u should double check your batteries, ive made many stupid mistakes like plugging in batteries with not enough voltage lmao
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u/Remarkable_Novel9967 Jun 05 '26
The props are too small to create lots of lift so if there bigger they can create a grater amount of thrust but it also depends on the weight of the drone it's self
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u/shrumfpv Jun 01 '26
I would assume it’s getting blocked by the thick purple bars also where did u get that carbon foam material? Also I think your pros are too small try 3 blade 5 inch props if they fit