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Pumpkin drop event

Quad problems, at least i think... some help please

#1
Hi and thank you in advanced!

It might be me, okay it probably is but... if you watch the short video and mainly listen to the motor sounds. When giving high throttle inputs a "shaking/oscillating" sound can be heard(not sure how else to describe). Also, i use dRonin for the software. That to has been a concern, do I Flash Betaflight instead of dRonin? I'm all for trying out different things, but at this point i want to know that my equipment is working correctly. Could this be a poor tune(which I use the Autotune feature with dRonin)? is this normal maybe? is this a problem of incompatibilities? I truly appreciate any feedback!!! As I'm sure this can be symptoms of multiple issues. This was my 1st build also.

Here's my build sheet:

Motors: Multistar V-spec 2205-2350kv
ESC: Multistar 32bit 20a Race spec
FC: BrainFPV RE1 w/mPB
RC rx: lemon rx 8channel ppm
vTx: unify pro (not HV)
Camera: Runcam Eagle
Frame: Space One Formula

 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#2
I love dRonin on my Sparky2, Brain and RE1. Not so much on a Naze32.

Did you autotune?

If so, what was your TAU number?

I hear that warble even at low throttle. I think you have a bad tune, a bad motor, prop or ESC in that order. :)
 

PsyBorg

Wake up! Time to fly!
Mentor
#4
From what I see this is all tune. The shakes in flight are P gains not set correct and the drifting is D gains. That gets accentuated on punch outs as TPA (throttle pid attenuation) needs some help. Its even more prevelant when you fall back thru your own propwash that tuning is needed regardless of anything bent or out of balance. However I don't feel it is anything out of balance or bent as when you coast it seems pretty smooth.

From what Litterbug and Jhetsema say DRonin is rockin now and they have that auto tune worked out pretty well so I would say stick with the Dronin and go thru the auto tune like Cranialrectosis suggests.
 
#5
Awesome guys!

I did do an autotune, the results are:
Roll .0289
pitch .0289
yaw ______

I have the latest version of dRonin released 20170213

Also, not sure if worth noting but i do the autotune with the action cam on. My thoughts were that the tune should be done in the same matter as the flying will be done.

props are not balanced, they are new for what that matters (DYS 5x4x3) nothing is bent

As far as bad motor, prop, and ESC goes. Last week while flying I had a crash, that the outcome was Left rear motor changed its rotation(CCW to CW). i found this very interesting. i replaced the motor initially, but had to wire the new motor(Which was exact replacement) with two motor leads swapped from the previous wiring. never had that happen, and didn't think that was possible without physically changing the wires. Making me believe there could be another issue all together. Anyways, all that being said I've been battling these wobbles from the get go, and have been trying to "enjoy" flying

Thanks again guys!!
 
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#7
A motor in the opposite direction would certainly cause issues. Check the directions again to make sure there spinning in the right direction. Could be damage to either the motor or the ESC.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#8
dRonin has been my ROM of choice for a few years now. I love the autotune.

dRonin autotune returns a number called a TAU. The lower that number (within the realm of reason) the better your build components 'synch' up to perform. In 2015 scores of 20 were good. Today with my Alien 4" with my 3000kv motors and rockin BLHeli_S ESCs with SBus receiver and I see scores of 9-10. The response on this machine is freaking AWESOME and to get there I throw a switch and tell it 'yes' in GCS.

You are correct crashbuildfly that you should tune with all the kit you will be using to fly.

I am concerned about your ESCs. Multistar is an old name and in 2013-2014 it was a synonym for crap parts. They should work but the performance will not likely be anywhere near an Aikon or KISS ESC or a Cobra, eMAX Red Bottom or T-Motor motor.

If you start replacing parts, look at better ESCs. :)

If when you autotune, you are consistently seeing TAU numbers in the high 20s or above, you likely have a hardware problem. dRonin autotune has pointed out a slightly bent shaft and a cracked bell on my Aliens. If your copter performance isn't what it used to be, run an autotune (you don't have to accept it). If the TAU numbers are high, something is broken. :)
 
#9
Okay very good info! I have done autotune now 12 times with this quad. I've actually been keeping track. I had better results (lower tau) in the past. But, never seemed as smooth as I see in others.

I really like the autotune feature, I'm sure I would really be lost without it. Lol!

I had my doubts about my choice of motors and esc's. But cost was more of a factor. And for a month or so I've been considering an upgrade.

Commandosqueak. The motor suddenly changed direction after the crash. Had flown 2 batteries, had the crash, went to fly my next battery and my quad wouldn't take off. Lol! I then found that the motor changed rotation! Still think it's strange. Lol!

i will go over it to be sure i don't have any cracks or anything else a bit more thoroughly as well. Maybe i missed something. I've had enough crashes so.....

PsyBorg and Cranialrectosis thanks for the help! Truly appreciate it!
Those were the tau from my previous autotune. The best results I've had (.0137). I will do it again here shortly. This way I can fly for the time being.
 
#10
So working through this I've checked over my motors. One of the motors has a wobble in the bell(no cracks). Don't suppose that could be the culprit?

1st autotune .0288
2nd .0308
3rd .0318

Then hypothetically, if I'm only able to get a mediocre tune. Are there any means by which I could alter the PIDs manually to achieve better results. In your opinions.

Later today I will be ordering upgraded motors and ESCs. Red bottom Emax seem to be all the rage, as well as the KISS ESCs.

I kinda thought foolish of me to go for the best right away as a noob. Not to mention, the amount of info i went through getting into it had my head spinning. lol, I didn't think I would enjoy miniquads as much as i do. Thought I'd be all fixed wing. Just, had to see what all the fun was about. haha
:D

Thanks again guys!
 
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ElectriSean

Eternal Student
Mentor
#11
Commandosqueak. The motor suddenly changed direction after the crash. Had flown 2 batteries, had the crash, went to fly my next battery and my quad wouldn't take off. Lol! I then found that the motor changed rotation! Still think it's strange. Lol!
Motor direction can be reversed in the ESC firmware, it's likely the crash damaged the ESC. More likely than an unintended motor lead reversal ;)