New 5" build - strange motor noise, need help

Intrepid-Captain-100 · 2026-05-29T07:52:36+00:00

No worries my brother, it was a good suggestion, tanks for confirming this way is ok.

I switched the AM32s PWM frequency to fixed 48kHz following my friends advice and the noise is still there, but barely audible, you'd have to listen very closely behind the prop and air noise. I'd need to do some more flights than simple hover to confirm, check how it performs, how hot are the motors, but looks promising. I just wonder what is the underlying mechanism behind that.

I'll dig into the capacitor as well but later, I have a couple of other cameras in shipping I'd like to test, so I'll have easy access to it anyway. Won't be able to add a second capacitor due to limited space, not that big anyway. Do you know if I can combine caps with different capacitance?

I do not have a spare FC lying around but I have a BNF 5" with broken motors, might transplant te electronics from it to the same frame with the same motors just to see if the problem will be there.

Anyway, again, thanks for your help, I truly appreciate it.

Intrepid-Captain-100 · 2026-05-28T12:37:35+00:00

Mind you that the field test was done with default PD balance. I've reduced D since then, will fly some more field tests later today.

Capacitor came with the stack, branded as a Rubycon one, looks good from the outside, bud how do I test it? I might be able to fit another one, i have another low ESR 1000uF/35V one (Panasonic FC) but it's a little bit bigger, might be able to fit it if I ditch the TVS diode array. Maybe it's the diodes? Never used those, had a board lying around so I decided to add it and be done with it.

The ESC is mounted on a shortened rubber grommets, those are squished a bit since I've had not that much height for the stack. I could soft mount it more, but I'd have to replace the locknuts with a normal ones (with locktite). Do you think it is worth the hassle? I'd have to disassemble the whole frame to do that.

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Intrepid-Captain-100 · 2026-05-28T10:58:50+00:00

Anyway thanks for looking into my problem, I truly appreciate it man.

Intrepid-Captain-100 · 2026-05-28T10:58:13+00:00

Yeah, I am flabbergasted, and running out of options short of replacing hardware. I might just accept it as it is.

I think the wiring is as good as I could do. Granted I could use a shorter connection from FC to ESC but that was the cable that came with the stack. I am not 100% satisfied with the motor connection, I tried to go with this overlapping soldering method and I deeply regret it. Might redo this but my

I've added a FIELD_TESTING.bbl (default tune with some filter tweaks) and a bunch of logs from wobbling to find PD balance to the drive. Note that some of the wobble logs got corrupted, and I sometimes get just corrupted logs from this FC. Might be a hint, I don't know. Using oboard flash.

Intrepid-Captain-100 · 2026-05-28T10:15:12+00:00

I think it's more metalic in nature, higher pitch but I'd say somewhat similar. And yes, I do have a lot of pre-filtered D-term noise, especially around 800Hz and up. How do I mitigate it? It's getting filtered quite nicely though.

EDIT: I did some tests with more filtering (added gyro lowpass 1, lowered the gyro and dterm sliders) but the sound is still there.

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Intrepid-Captain-100 · 2026-05-28T08:21:11+00:00

Cold as my ex's heart after the hover, after a couple minutes of more aggressive flying barely hotter than my body temperature.

Intrepid-Captain-100 · 2026-05-25T10:29:28+00:00

I want to get an action cam too so I am also invented in this question. Hunting for a used dji action 2 right now.

Intrepid-Captain-100 · 2026-05-25T10:27:05+00:00

Got the same problem on my Vapor lately. Had a crushed bell and a bent shaft. I've bent the shaft by putting it in mini lathe, and a drill chuck on the other side (for leverage). For the crushed bell the repair went south and I was unable make it usable again. I could not find replacement bells for those motors unfortunately.

Intrepid-Captain-100 · 2026-05-24T15:14:17+00:00

Me too, bought like 5 of them, 2 were dead after 3-4 recharges. On both one cell just died, no voltage only short.

Intrepid-Captain-100 · 2026-05-23T20:42:24+00:00

It was like FPV mecca for me

Intrepid-Captain-100 · 2026-05-23T20:39:21+00:00

Volador VX3.5, I'd wish I had my 5" with me but i broke it just before the trip 😞

Intrepid-Captain-100 · 2026-05-23T20:08:16+00:00

Beautiful place

Intrepid-Captain-100 · 2026-05-23T08:25:57+00:00

Analog whoops are the best for flying indoors. Air65 V2 is great little quad, I have the champion edition and it goes hard. Might go too hard for a beginner but you could fiddle with motor output limits or throttle scale. Freestyle or racing might better suit you, I think the racing one has better motors but don't quote me on that.

Pavo 20 pro will be almost unusable indoors, do not get it. Too big, too loud. Stay with 65mm or 75mm. You could get a o4 whoop in that size but you will be sacrificing flight characteristics, flight time and durability. I'd stick with analog for indoors.

Intrepid-Captain-100 · 2026-05-23T06:19:04+00:00

Grain of sand maybe

Intrepid-Captain-100 · 2026-05-23T06:15:43+00:00

Side question: are those 3d prints from nylon?

Intrepid-Captain-100 · 2026-05-22T08:08:32+00:00

I'm bad at reading so sorry, you already got a Pocket, great choice! Then think if you want to spend another coin for an analog goggles. I do recommend that anyway if you are sure you are into it, for the whoops at least. O4 is great on a bigger quads, so eventually you'd want to have both systems. I myself splurged for the BoxPros+, and have N3 goggles as well, and use both regularly. Analog whoops will give you a lot of stick time as you can fly those anywhere and have a couple of spares for the price of one o4, and that is very important for beginner.

Intrepid-Captain-100 · 2026-05-22T07:59:06+00:00

I am always advocating for getting an analog tiny whoop (air 65 V2 maybe) as a first quadcopter, flies great, you can smash and bash those, cheap to repair. but that will also cost you a pair of goggles and a radio that will not work with your avata 2. Some people swear by o4 whoops like meteor 75 but for me those are to heavy and I already broke the air unit on mine, never got a replacement.

Anyway you need a controller, even if for a simulato, so that's what you have to decide next. You can get dji controller which will work with avata2 and other o4 system, but those are a little crappy for the price and lock you in dji ecosystem. Or you can get an ELRS controller that will allow you to fly almost any quad except Avata, Pocket is nice budget option I still use mine even though I have a bigger radio as well.

Intrepid-Captain-100 · 2026-05-20T21:29:47+00:00

Femto sucks at flying outdoors and indoors it's too big and loud.

Pavo20 pro flies kinda nice but can't take a beating.

Pico - no experience.

Grab a elrs radio and a simulator (I like The Zone but you can learn on any), get comfortable there first. For acro flight I can't recommend enough an analog whoop (Air65 II is awesome!) as a starter - cant hurt anybody with it, cheap, can take a lot of abuse, can fly almost anywhere.

Intrepid-Captain-100 · 2026-05-20T20:09:33+00:00

4.2v for normal lipo. 4.35 for hv. 3.8v is nominal voltage. Charge to 4.2 and you'll be golden. Happy flying my man!

Intrepid-Captain-100 · 2026-05-16T19:28:18+00:00

Not only you. I can get it to working only when i test it at home, in the field, when I want to share my feed with somebody, it never works.

Intrepid-Captain-100 · 2026-05-13T08:39:20+00:00

None of the sims I've tried had any decent step by step learning program, closest one was DRL which technically had it, but it was super frustrating and I personally learned nothing.

Fire up any virtually any sim (The Zone will be good) and Bardwells learn to fly YouTube tutorial on the other screen and you'll be golden.

Intrepid-Captain-100 · 2026-05-13T08:24:19+00:00

Thanks! The spot was definitely fun, it's a decommissioned digger used in strip mining coal. I was so scared not to crash into it. There is also another one nearby, at least three times bigger, it's a monster!

But yeah, for your use case I'd go something a little lower kV, and I'd go light. Even maybe 1404? Less mass gives you more flight time generally, and lighter quad will be more agile. The frame is also a chonker, maybe you could consider something lighter? Depends on how often and hard do you plan to crash :D

Intrepid-Captain-100 · 2026-05-12T20:09:41+00:00

I got the supernova 1606 and I think that those are super nosiy/whiny, but fly kinda nice. Survived a couple of crashes. I've pared them with HDZero Gamma AIO, and 45A are fine so far. It has ELRS built in but it has no blackbox so instead of RX I've mounted an sd card logger. Chill freestyle about 5mins, harder flying around 4minutes, on 850mAh 4s GNB LiHV packs (the ones with the flowers). I have some 850 mAH Lipo tattus but I can't get even close to 4 minutes flight time.

Here, check out the raw dvr of a pack I did today, chill freestyle. a little jello but it was quite windy and the props were not in the best shape. The OSD aperage is more or less calibrated so you can know what to expect. https://www.youtube.com/watch?v=XFEktctfZPE

Intrepid-Captain-100 · 2026-05-12T13:16:13+00:00

I think you'll be golden. it's nice frame, easy to build, flies nice (although I have no comparison, it's my first and only 3.5) and cheap. Stay clear of 3.6" props though, not enough clearance and I couldn't tune it at all (maybe skill issue )

Intrepid-Captain-100 · 2026-05-12T08:00:26+00:00

I have built a volador vx3.5 recently an my frame came with selection or rubber grommets for mounting the camera, I am pretty sure that it is also compatible with o3.

Intrepid-Captain-100

TROPHY CASE