Mikrokopter Galloping Okto

[Bartman]

With a flight done to establish that I'm moving in the right direction it's time to get the nitty-gritty details worked out. First up is a very slight galloping motion during hover. It's an 8-rotor MK heli using CheeSC's (chinese ESC's) and I'm wondering if there's something known that has to be detuned to accomodate that the CheeSC's aren't quite as efficient as MK's BL's controllers.
My camera mount is only partially installed so it could be that the copter is fighting that imbalance but it's doing it in a way that is causing a very subtle rhythmic front to back rocking that makes it look like a horse galloping. I'm wondering if the PID's have to be detuned a bit.
THanks,
Bart

 

[Droider]

Good luck buddy... I am still trying to find out about stuff that I cant get answers for on the MK forum for weeks.. and all my kit is MK!

 

[Bartman]

when all else fails, load it up with weight and see what happens! it's been mentioned to me that the frame is more stiff than a std MK frame so maybe the board isn't coping with it as well as I'd like.
Thanks
Bart

 

[Droider]

Na... what firmware you running?

 

[Bartman]

.80g
i should get that to at least .82
didn't even realize i still had .80

 

[Droider]

Give the 82 a go

 

[Macsgrafs]

Dave what's the difference between the 2 versions?

Ross

 

[Crash]

Dave what's the difference between the 2 versions?

Ross

.82 adds a few insignificant features (IMHO) and likely some bug fixes.
.84 adds some waypoint features that some people may like and it probably adds some bugs too.

http://www.mikrokopter.de/ucwiki/KategorieFirmware

Bart: If I'm not mistaken RTRyder has used an I2C convertor board on his Octo. I'm guessing you are also using one? Maybe you should send him a PM directing him to this thread. It's not apparent from the title or first post what convertor you are using or if you are using one at all.

From what I recall some changes do have to be made to the settings. For all the problems that the MK ESCs have, they still perform great when they work.

 

[Bartman]

it's all coming back to me now. when i bought my first MK stuff last November, version .82 either just came out or was about to come out and there were issues with it. my version .80 worked great so i never bothered updating. i assumed the new FC i bought recently had the latest firmware revision so i never bothered checking it (plus i'm in a continuous fog from trying to do too many things at one time). If .82b is stable then i'll use it. i've uploaded it to the new FC and I already like the improved camera motion in Nick. In fact this solves the problem I had with the very notchy camera action using the side slider on my JR 9503 so that issue is put to rest.
We'll see if it takes the gallop out of my OKto's hover when I fly again tomorrow. Maybe I'll take a video and try to redeem myself
Bart

 

[Bartman]

.82 adds a few insignificant features (IMHO) and likely some bug fixes.
.84 adds some waypoint features that some people may like and it probably adds some bugs too.

http://www.mikrokopter.de/ucwiki/KategorieFirmware

Bart: If I'm not mistaken RTRyder has used an I2C convertor board on his Octo. I'm guessing you are also using one? Maybe you should send him a PM directing him to this thread. It's not apparent from the title or first post what convertor you are using or if you are using one at all.

From what I recall some changes do have to be made to the settings. For all the problems that the MK ESCs have, they still perform great when they work.

Crash,
I asked Ken in an email earlier today and he didn't have the problem so he wasn't able to offer any possible solution. I think the combination of full weight on the frame and the new FC rev will improve things. From there I can only try to tune the FC for the frame/motors/esc combination.

I'm using Timecop's revised I2C converter but I'm starting to plant he rebuild of my original MK Okto and will do the full MK power board with the Avroto motors so I should have a pretty true apples to apples comparison (MK I2C vs. CheeSC's) at some point

I'm looking forward to going back to only using 10% (or less) of my brain for a while. It can't come soon enough!

 

[RTRyder]

I had mine setup as an X8 so it wouldn't really be same anyway.

Bart, you did do the proper calibration of the ESCs, yes? By that I mean attach all of them to the I2C converter and install a bind plug on it to do the calibration. If they were done any other way it might be contributing to the problem as they may not be 100% in synch with each other.

If you don't already have it, download the manual here, it explains how to do it... http://www.abusemark.com/downloads/stm_manual_v2.pdf

Ken

 

[Bartman]

i did the group hug after i had them all wired up. we followed it with campfire songs and smores (i need some sleep)