MicroArduCopter, 3" props, Omnibus Nano, Success!

[anbello (Andrea Belloni)]

@andyp1per

I’ve run autotune on 4.0-something ok. Whether it was rc2 or not I don’t know. Worked ok. Can you reproduce it?

@andyp1per I had the same problem with Autotune and now I have the log, could you please take a look at this post:

Autotune failed to save new PID with Copter-4.0.0-rc2

It is the second time that this happen to me. The first time with a little 3inch with revo-mini so I have no log. The second time happened with a 5inch with Pixracer and so I have the log. I did Autotune on the three axis, I tested both old and new PID in flight then I landed with Autotune On and disarmed. After this I saw on GCS (Tower on Android phone) the new PID, but after power off - power on I saw the old PID. Using mavparms.py I could extract the parameters both from df log and from tlo…

[AfriCopta (AC)]

If you need i can upload a 3d Printed Frame for you, Size is 3 Inch and looksg similar to this you better can buy at Banggood: GEPRC 3mm
I printed this Frame, modified to 20x20 only and actual working on some leight weight ducts:
How to build the lightest Ardupilot microquadcopter 3-inch “2-stack” frame

Im using this Motors: Motor 1106-4300KV (2-4S) AMAXinno
Very quit and check the Thrust table:
190gr - 6 Amp on 2s
348gr - 12 Amp on 3s
if used with 3 Inch Props.

2 Inch is to small for 18650 Battery weight.

[AfriCopta (AC)]

Im happy you rescued your Copter!
Had such a Problem on my Phantom Clone with Mini Pix on Arducopter only one Time.
Dont know why, but i was unable to send any Commands to the Copter…like there is no connection to the RX…but RSSI was fine in OSD.
So i know the feeling wen you think it is lost, then RTH kicks in and you see your Baby flying Home

[Alberto_Ds]

Thanks!

[Alberto_Ds]

Andrea can you try with new 4.0 RC3?

[anbello (Andrea Belloni)]

Thanks @Alberto_Ds, anyway that was not an issue with Copter 4.0.0 but only a wrong habit of mine that was OK with 3.6.x but not with 4.0.x. as explained here.

[Alberto_Ds]

Hi all … For optical flow on 3" quad, which is best choice?
Thanks

€ 10,50 8%di SCONTO | Flusso ottico Spot del Sensore di Posizione di Volo Di Telecomando In Bilico In Possesso di Bordo del Modulo Costante VS Cheerson CX-OF Supporto APM
https://a.aliexpress.com/nQ7LsuMjh

€ 12,88 6%di SCONTO | 1PC 3.3V 1.1*1.4 centimetri 1g Sensore di Flusso Ottico Modulo Aerea Modello Accessori Per Il MINI FPV da corsa del RC Drone Quadcopter Pezzi di Ricambio
https://a.aliexpress.com/OfpnI5G3t

[Alberto_Ds]

Hi, I have a new 3" build, but the same problems! Roof rocket in althold. With omnibus nano v6 I have a log and I can see the graphics of vibrations … It’s too high?
Thanks

log added

1 01-01-1970 01-00-00_rocket.bin.log.zip (704.5 KB)

[dkemxr (Dave)]

That log is incomplete/corrupt and it wasn’t hovering long enough to determine levels of vibration. Attempt a hover in Stabilize mode and post a link to that.

[andyp1per]

Apropos of nothing I have discovered that both the KakuteF7 MIni and the Tekko32 mini have a conformal coating - which is very cool.

[wicked1 (S)]

That’s good, and I think it’s becoming pretty common. (At least a bunch of ESC’s I’ve got are coated… Speedix, Aikon, etc). More than just water resistance, protecting from conductive dust and other debris is important.

I think waterproofing one of my little copters is my next project.
I’ve played around w/ it a bit in the past, and haven’t found the thin silicone conformal coating to be 100% water proof… But maybe need more coats. I’ve seen peoples copters where they basically plasti-dip the entire thing… But that’s adding considerable weight. And getting something to adhere to silicone insulated wires will probably be an issue. I’d imagine almost everything will release and water will get under the coating at the wires. There are a lot of little details to work out.

Maybe vacuum forming a shell for the copter and waterproofing the seams is a better route to take than sealing all the PCB’s…

Did you get a new small copter built after your accident last month?

[andyp1per]

Most of the parts arrived this week and I got a variable temperature soldering iron for Christmas, so having done it once I am pretty much most of the way through not repeating the mistakes I made last time.

I’ve used acrylic conformal coating in the past because you can solder through it easily. Not great for wires though, but maybe nothing is.

[wicked1 (S)]

I just finished a copter today that I’ve been working on all winter… Supposed to be the final product of all the testing I did w/ other copters over the winter (testing the new kakute mini and all the vibe issues I was having, etc).
This copter has the least vibrations out of any of them… But it has the lean issue very badly. It’s not really flyable w/out GPS signal, because for whatever reason, having GPS makes the lean issue go away for the most part. W/out GPS, it’s pitching forward and leaning to the left more than I can compensate for, after I’m flying for a couple minutes.

I really don’t get it. Vibes are around 5 in the logs. My other kakute mini copter I was working w/ all winter is 15 on average and peaking to 30+. It had the lean issue, but much less than this.

Maybe I’ll try rounding up everyone w/ the issue and see if we can get logs and figure out if there’s anything we can do about it. Marty was recently posting about the issue on his copter and me and a couple other people quickly blamed vibrations. I was completely sure it’s vibrations. On that last copter, as I fixed the vibrations, the lean issue did get better. But now I’m not sure again. I don’t think it’s possible to get them lower than they are. so frustrating.

[wicked1 (S)]

@andyp1per

I got a variable temperature soldering iron for Christmas

I got the ts100 portable temperature controlled iron to put in my backpack for repairs while I’m out. But it’s really great! I use it for almost everything now… other than when I need a very hot iron.

[anbello (Andrea Belloni)]

Hi Alberto
Sorry if I repeat myself:
Are you using rubber grommet to dump the FC?
Are you using foam to cover the baro?
Next step dynamic notch to filter vibrations.

[Alberto_Ds]

Hi Andrea, obviously yes!
I used the ones supplied with the nano v6 omnibus and rubber ring on the nylon stand off. Double foam on the barometer. I thought a 3 “was less critical than a 2”.
I’m waiting for the usual, I think they are indispensable on any nano copter

4 PCS IFlight M2 M2*6+4.5 / M3 M3*7+4.5 Anti-Vibration Damping Fixed Screw...

[Alberto_Ds]

I have a question about these parameters, that i have setting in this way on my 2" quad and 3" quad:

ATC_ACCEL_P_MAX,125000
ATC_ACCEL_R_MAX,125000
ATC_ACCEL_Y_MAX,30000

I can’t find anything on threads about defalut param on sub 250

Default parameter set for sub 250 multirotors

I am starting this thread for people to propose a default parameter set for sub 250 sized aircraft. This should make it much easier for small multirotors to be set up using ArduPilot. I would like as many people as possible to post what they believe is the important parameters to change to get good performance from this class of multirotor. I will put the parameters we have settled on below: ACRO_BAL_PITCH ACRO_BAL_ROLL ACRO_RP_EXPO ACRO_RP_P ACRO_THR_MID ACRO_TRAINER ACRO_Y_EXPO ACRO_…

What the right setting for 3" quad?

Thanks

[ambattuhari (Hari .P)]

Auto Tune came up with ~ 37xxxx (P_MAX & R_MAX) for a 3"

[anbello (Andrea Belloni)]

On my 3" quad with 1104 5400KV motors and 2S battery I have:
ATC_ACCEL_P_MAX,240000
ATC_ACCEL_R_MAX,240000
ATC_ACCEL_Y_MAX,40000

[andyp1per]

I set them to 0 - which means basically go as fast as you can. On big copters this is a bad idea because you can overload the motors but on small copters I don’t think there is much of a downside. Autotune will set these base on the fastest response it sees from the vehicle when twitching.