Hey All having an interesting issue with my Octocopter... Wanted to see what the pros


BorisS

BorisS

Drone Enthusiast
What systems do you have running WKM or MK ? And you are noticing similar behavior before take off ?

Boris
 


BorisS

BorisS

Drone Enthusiast
nytram said:
Looks Like the gains could be to high
Click to expand...

Well the one flying in the video seem to be a MK setup. But the reason could also be a PID running issue. But you are right a similar behavior with a WKM setup could be to high gains setting and oscillations kicking in !
 

3

3dheliguy

Member
Hey guy, yeah I currently running WKM on a Cinestar rig, and Maytech 65 amp ESCs in conjunction with KW8s. The kopter itself is showing signs on take off, and I have slammed the gains down to 45 on attitude then she calms down a bit, but just doesn't feel right. The basic gains are at 120 all the way through the vertical being 120, but as soon as I get on the Attitude gain it just seems to bounce around like crazy. When I had her at 120 120 on attitude she looked like a yo yo rocking back and forth.

I was just going through some pre flight before the gimbal and the camera were installed. I'm not to sure what's going on or if the octos just have to run low gains with it's all up payload. But this thing even at low gains is just not smooth at all when I try make a figure eight flight pattern.
 
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3

3dheliguy

Member
Could this have something to do with the Z Axis of the IMU and the batteries being on top, in witch it need to be spot on for CG.
 


BorisS

BorisS

Drone Enthusiast
Since attitude gains mainly interpret the stick input from you TX have you looked in the assistant if there is anything weird going on with your TX RX setup ?
Do you see the sliders in the TX config moving although they should be resting in the middle ?
 


FerdinandK

FerdinandK

Member
From my point of view there can be one of the following (of course also something else)

Wrong octo-type set in WKM Assistant
Not all motors connected correctly
IMU not positioned straight forward and/or the orientation is set wrong in the WKM Assistant
IMU position not entered correctly in the WKM Assistant
ESCs are not all calibratied correctly
BASIC gain are too high (not the atti-gains)

best regards

Ferdinand
 



3

3dheliguy

Member
Ok so I went ahead and tuned again today with minor changes to the gains.


The gains are currently at 150 across the board for all basic gains. The attitude gains are around 65 and Im still seeing instability in the copter while hovering. It does seem a little bit better, but I feel there is something that im missing here. I went back and forth on all gains fluctutating from 110 to 170 only to find the problem persist. Im begining to think its within one of the ESCS themselves.

Also Im seeing the same results while flying in Manual Mode. So this leads me to believe its withing the ESCS. Let me know what you guys think.

So next will be recalibrating all ESCs.

I checked all my connections and reconfirmed my IMU, and GPS positions
 

3

3dheliguy

Member
I went ahead and tested again today, I played with all gains to trying to find a sweet spot within the wookong gains adjustment only to find that problem still persists

I reconfrimed all IMU postions as I thought that might be an issue but this was perfect.

All Basic gains were set from 150 to 110 fluctuating trying to find a seet spot, but this was not possible. It just seems that something is throwing the system off.

I will be recalibrating ESCs later to see if that helps.
 

A

ATFlyer

Member
My SJ8 flew like you are describing yours when I had big props and no weight. Nothing I did to the WKM seemed to make much difference - I couldn't get the Atti gains above 49%!
i was advised to put 13x6.5 props on & there was an immediate improvement. I'm flying a 5D, all up weight is 11.5kg and the 13x6.5 props are perfect - lots of power, VERY stable even in a 20mph + wind.

I'd try flying a bit of weight.

Good luck
 

3

3dheliguy

Member
Thanks Atfflyer.

Im coming to this conclusion to. After recalibrating the the Escs and seeing no differance, and all Imu, Gps positions seem perfect. So I believe your correct in that it needs to be proped down and to add some weight.

Thanks everybody.
 

danproud

danproud

Member
3dheliguy....

I'm having the same problem here on my Cinestar6. Gains too high, it rocks itself into a crash, then gains lower, something just feels wrong. Using APC slow fly 14X4.7. I've got a battery mounted on top, no camera in the gimbal.

Did you end up adding some weight, and did that help?
 

3

3dheliguy

Member
Yes, I am still tuning but from what I can tell, the Cinestar configuration such Octo I seems to be a little more of a handful in the tuning process. But I'm starting to have success... I recently proper it down to 13x6.5, and raised my basic gains to around 170 175 with my yaw around 134, and it seems to be getting very smooth. My atti gains are around 75, but this might be very different for you since your running a hex a.

My advice would be prop down, and add some weight. The system is to light also try 12 or 13x6.5 the smaller the better until you add a fair amount of weight.

Im not to impressed with APC 14X4.7 they are just feel weird on wkm helis.
 


danproud

danproud

Member
Ordered smaller props but got sick of waiting for them to turn up. So I added weight - 1.5 kgs. Bam! the thing flies 100% better! There was no wind, but the Cinestar seemed really stable. I figure the CS6 with its 14x4.7 props is NOT designed to fly without a camera!

Will be interesting to see how the APC T/E 13x6.5's go with the payload...
 

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