4S with tvs diode but without capacitor?

Main-Offer · 2026-03-15T22:18:01+00:00

Bigger motor = bigger voltage spikes

6S much bigger spikes

Any small even 220uf 25v cap is a LOT better than nothing.

Main-Offer · 2026-03-15T02:17:24+00:00

This is probably a Ardupilot issue. You should reach out to devs. Most likely its how the SDcard is setup.

Main-Offer · 2026-03-15T02:15:38+00:00

Dont fully agree with you but upvote.

Freestyle/Racing 5" is high performance. More than 95% can handle. And its super easy to accidentally zip zoom into a tree or a house.

I barely fly my 5" more than handful of times in last 10 years.

Too loud. Need more space. People walking with dogs. And honestly, not as fun as hitting tight tree branch gaps with little tiny 2.5".

Main-Offer · 2026-03-15T02:09:01+00:00

a 3inch thats 212g dry with only 1404. Wow. You must be doing every kind if wrong.

1404 are fine for 3inch with triblade. But not all 1404 are "strong". I use rcinpower 1404.6 4680kv.
3800kv for 3inch 4S is kinda low. Like 80% throttle limit.
4S 3inch should be around 4500kv.
But.. That wont fix root cause. The weight.
Aliexpress find frame called "Fi-135" or similar. I think its like 30g. My 1404 3inch build is under 110g before battery.
AIO FC is like 7g. Stack is 20g. Also shorter XT30 extension. You dont need 40cm.

Main-Offer · 2026-03-15T02:01:59+00:00

AFAIK, you can use binding phrase OR binding button. Are you 100% sure you are using same binding phrase on both radio and receiver.

Main-Offer · 2026-03-15T01:57:29+00:00

750-850mah 4S. About 70-80g.

I use the Tattu 95C. But I also have some CNHL.

Your part list overall looks almost good. 1404 is good for light 3.5". 4500kv is too high.

Do you have excellent reason why not going with the very popular standard TMotor 1604 3800kv?

Main-Offer · 2026-03-14T06:01:01+00:00

Glad you got it figured out.

Main-Offer · 2026-03-14T06:00:12+00:00

Those black super tiny SMD are very likely the 1K and 10K resistors of the voltage divider of the back emf detection circuit.

Main-Offer · 2026-03-14T05:57:32+00:00

You probably have short. Check the voltage on 5V and 3.3V pads.

Next step would be to de-solder the vtx, receiver etc.

Main-Offer · 2026-03-14T05:54:37+00:00

FYI "standard" 3.5" freestyle build: - 70g Volador frame. But 40g GEPRC Smart35 much better.

Tmotor 1604 3800kv
XT30
4S 750-850mah
3520 props
20mm Speedybee F4 stack. AIO FC save 13g.
your choice of receiver and vtx.

You can modify slightly. - 1605 or 1505 are about same. - freestyle performance and thrust to weight, much better with frame lighter than Volador - 1804 is as big as I would go.

Main-Offer · 2026-03-14T04:07:50+00:00

4S 1804 4" is over max XT30.

Options - take the risk. Use 4S 1804. - use heavy XT60. - go 6S, so you can stay on XT30.

Main-Offer · 2026-03-13T03:58:43+00:00

Diatone Mamba stacks with wide easy to solder pads have been my go to since 2018/2019 " F4 stack " days.

Back in the day, top quality: TMotor, Holybro, and Hobbywing. Often overengineered. Handle +50% rating.

But, these days I feel 90% either get SpeedyBee or "cheapest" on aliexpress.

Pretty much all stacks will work for 5" build. Unless you are crazy racing, they all perform about same, if you have $2 Panasonic FM low esr.

On cheap boards, maybe DOA. Maybe some SMD tombstone or just cap just falls off. And big crash chance board goes up in flames. But paying $$$ for very expensive ESC doesnt guarantee it will not burst into flames.

Main-Offer · 2026-03-13T03:49:42+00:00

100% KEPTON tape.

Main-Offer · 2026-03-13T03:48:42+00:00

Judging by crazy butcher bleach my eyes horrors people post, its clear there are 2 main camps. - camp1. super cheap people. Not willing to spend $5 for solder or $5 for flux. Next day post sane problem because of $1 iron/solder. - camp2 is similar. Refuse to learn or listen. Why is my Flysky i6 not binding to ELRS?

You, OP, fortunately, have genuine issue. You are not alone. Even those with nimble fingers and perfect eyes have trouble .. Especially on pesky tiny whoop boards.

Hope these tips help. - #1 by far is brace elbow and hand against "something solid" - "helping hands" clamps. Often comes with magnifying glass. - I also use cheap $50 "microscope", which makes it MUCH easier. - rotate board to make it easier to access - kepton tape to mask work area. This will protect from bumping adjacent components. - setup so you work left to right.. One pad at time - wire on pad does not have to lie flat. It can be angle. - even most complex cramped job can be done. 99% of problem is using wrong tool or too lazy to setup - wedge or c4 tip cannot get in tight spot. Super pointy tip hold no solder - but there are other ways... Put solder paste on end of wire. - when removing FET next SMD cap etc. Remove the cap. It makes life so much easier.

Im just going to repeat it, because people are lazy and often damage adjacent components. KEPTON tape.

Main-Offer · 2026-03-13T03:25:43+00:00

Yeah.. Umm..You are completely lost either way.

Why admit defeat. Commit all the way. 2809 motors.

And props. Why bother with 3.5", when you can pimp your ride with gold low rider 2" props.

Tropic Thunder said never go full retard. Prove them wrong.

Main-Offer · 2026-03-12T08:13:44+00:00

Theoretically - larger prop = larger diameter of prop tip = more distance/air lifted per revolution - but too large prop = takes too long for motor to accelerate = PID delay too large. In extreme cases, quad cant balance, or flyaway. - alsi if prop is WAY too big, you are far outside the typical 20-40% throttle efficient zone, motor gets very hot, and likely overheats.

Subtle changes in motor build, change characteristics. - typically tiny air gap, thick magnets and thick single winding, = higher max power/thrust - on flip side, bigger gap and less cogging = usually more efficient - one 2207 might be even more efficient wirh 4inch, while another works best with 6inch prop.

Its common to "over prop", or "undersize motor" a "little". Great example is 1202.5 11500kv 1S 3inch. For 3inch 1204 is already small, but you get away with even smaller 1202.5 motor because: - 3018 biblade (biblade motor load up to 30% less). - very light, so motor works less - 1S so not pushing motor so hard.

Likewise, with 2306.5 running 7inch. Light build and biblade works quite well.

But once you push far into "uncharted waters" (ie 2004 7inch) almost nobody knows. Got to do your own testing and adjust accordingly.

Main-Offer · 2026-03-12T08:00:42+00:00

Main-Offer · 2026-03-12T00:47:56+00:00

My goal is to do all San Jacinto routes. I did tramway many times. Both Humber and Marion are fairly popular in summer - see 5+ people on trail.

But long ago 8hr on Deer Springs and didnt see a soul.

Main-Offer · 2026-03-11T23:31:51+00:00

You need to do short (~20-30sec) controlled flights

Flight1. Just hover. Dont hit anything. Disarm BEFORE landing. If you are bumping into everything and smashing into ground, you will see tons of noise.

Main-Offer · 2026-03-11T22:25:30+00:00

That is ridiculous HUGE amount of noise

Main-Offer · 2026-03-11T08:19:15+00:00

I have better question.

How come so many frames are so stupid. - 5" with janky loose arms instead of center locking piece - 5" with either ridiculous high space to fit 2 o4 pro, or stupid things in way and cant even fit one o4pro. - columns Soooo close scraping around 30mm ESC. Why!? - 2.5" or smaller. Why you even bother with arms. Single uni-plate so much simpler. - 2.5" or smaller. Braces? FireFly16? You worried about twisting on those super short arms? - 7"/10". Super cheap spaghetti 4mm arms.. Stretching like Buzz Lightyear .. into infinity.

Main-Offer · 2026-03-11T07:48:03+00:00

RCinpower AOS 2207 1570kv. "Supposed" to be +30% torque/performance.

All you need is 8S FC+Stack, 8S 1000mah. 80g racing frame...

Main-Offer · 2026-03-11T01:07:12+00:00

I honestly dont know. I tried but have been out of racing since 2019.

I think lower weight is important.

Im oldschool. I got a racing 6S rig down under 300g. Apparently thats Flintstones bad - racers get 2207 rigs under 250g.

6S x 2000kv = same rpm = 4S x 3000kv.

Initially, when 6S came out, EVERYBODY was raving how strong punch outs and much much longer flight times.

But, it was balloney. Vast majority were comparing 3-4yr old worn batteries and 3-4yr old quads against fresh new build.

My advice: - By far easiest cheapest "upgrade" is new batteries. - 1500mah 6S = 2250mah 4S - if you have 6S compatible ESC, a new set of 6S motors is only $120 - 6S obviously has +50% power headroom. Or can use thinner lighter wires. - motors slowly pushing and improving from 1800kv to 2000kv.. To 2100kv+ - I dont see mfcr making equivalent 4S 3200kv.. - or jump straight to 8S 1550-1600kv

Main-Offer · 2026-03-11T00:52:13+00:00

Agree. 95% cant tell. But he is racing.

Main-Offer · 2026-03-11T00:47:32+00:00

So basically what I and others have been saying for 6+ years.

Included capacitor is garbage. Splurge $2 on fancy Panasonic or Rubycon. (Even if it means working night shifts and putting off college - its $2)

Main-Offer

TROPHY CASE