Hi

I did the upgrade on the A2 on a S900 and gout some trouble as the Z-15 went nuts after take of and broke but DJI is taking kare of it.
But after the new upgrade (with the same type of Zenmuse and camera) the Gain seems different then before.

Its like its more "jumpy" on the respons. It was really easy and gave me lots of confidence before the upgrade.
I keept the same settings but its a totaly new experience. I recalibrated a few times to see if I did not do a good
enought job there but im now sure its not as it used to be. I used the adviced settings as before. See Att.

Anyone got any experience like this and did you change someting or got any advice.

Do you have more details about how it acts? Does it shake when it is hovering? or acting strange when responding to your control?

I try to show you as much detail as I can as I got some more experience today.

Just to make sure first. The rig is now without a Gimbal, but I have centered everything and tested it so thats ok. Also done re calibration outside twice. Plus I have re installed the firmware also twice using a procedure I got from DJI that might be known here on the forum but I was asked not to reveal. So all should be fine.

How it acts.

Now its perfect "back and forth" + up and down and make it go "left and right". It also stands perfectly still in the air when I let go of the sticks. PERFECT there. BUT when I try to make turn around even standing still it goes nuts. Im trying to make sure im understood as Im not sure what is the correct word for making it go 360 using the left stick to one side (Sorry about the lack of know how there :-))

Then its like its loosing its balance. It wiggles back and forth and today when I tried it a bit hard to press it , it tilted and hit the ground sideways. If I try and explain it kept turning around as it just went 90 degrees sideways and slammed into the ground. Like it could not keep the balance but still tried to do the movement.  It was really close to the ground over soft grass and happened so fast I think I still hold on to the stick the first second.

Broke a few blades but was lucky. It was a few parts on the ground as we have driven some ATVS, Sleds and MX bikes over this area. I found one part I was not sure was from the S900 and include a photo but cant see it belong to it.

After this I tried it again and it was the same but this time I did not press it. Re calibrated and still it was there.
When I now go into the setup I get the settings you see in the screen shot. On the Roll you see it say K1. I never seen that before.

Hope you might be able to help.

More screen shots

Change the drop down to 100% the same as others.

I would raise basic to 145 and drop atti down to 135. This is where I have mine and she is rock solid.

Imu needs to be negative as well.

I will try that.
When you mean Negative to mean IMU X = -10 ?
here is where I placed it according to the S900 Manual

Thanks again!

PS: Note sure what you mean about Att down.
Is it like this?

Basic
Pitch 145
Roll 145
yaw 145

Attitude
pitch 135
roll 135
vertical 140

Imu should be negative number, green is alway negative.

Fantastic.
So this should be the correct setting? :-D

That looks good to me.. you might have to fine tune these settings but these are a solid and safe starting point.

Blade_Strike Posted at 2014-11-28 01:30
That looks good to me.. you might have to fine tune these settings but these are a solid and safe st ...

@rubenmail
are you sure of the values set in the tab voltage?

I used this Tattu battery now just for showing and changing settings. I usually use Xmateria PRO Series 6S Lipo 9000mah AS150.
Here is a screen dump of my settings to.

I think he was just making sure you wanted voltage protection off?
I turn it on but leave all fail safe functions off. I like to see via led but would rather destroy a battery than lose the craft.

Blade_strike : I agree :-D

So like this?

Yep, you will see the warning led but it will not rth or auto land.

Blade_Strike You done it again. THANKS!!!

Anyone of you use A2, gh4 gimbal and Lb? Seems to me that this setup cant be used as one person setup??

I'm using mine as a one operator setup, you will have 12channels to work with.

Blade_Strike: Do you use a extra Futuba TX on the S900? I only have 3 channels left after mounting the LB and Landing gear.

i'm using S900, A2, GH4 Gimbal and LB, so you have 12 channels one operator, which TX you are using maybe you need an SBUS Expander from Futaba and an Hub between.

What gimbal are you using? HD gimbal does not require F ports to be used. You will have a total of 12 ch on single operator setup when using the LB.

Blade_Strike: So if I got this right you get the more then the 3 channels you have "ports" for left on the A2 in the HD gimbal?
I only have the Z-15 with Sony Nex 7 on it now.

dude.. i think you got the whole  IMU and GPS axis wrong. The GPS placed in centre of S900 , should read 0,0,-20 (depending on the stick length + distance to CoG)

The IMU should be -6 or something, 0, - CoG

SpreadingWings Posted at 2015-1-31 18:06
dude.. i think you got the whole  IMU and GPS axis wrong. The GPS placed in centre of S900 , should  ...

Hi

Sorry for the late reply. I have been sick and away.
I got the Zenmuse back from DJI and I just sent everything to our service partner ( http://bublisher.com/our-partner-on-drones/ ) for service and adjustments so I see when I get it back. :-)

Had a similar issue with my octocopter...would float/ hover then begin to wobble and tilt to the side and crashed...Did fixing the gains help you?

Hi

No it was another problem. We use a partner to handle service. Let me send them a notice about this and they can reply here and explain what they did with our.

R

rubenmail@gmail Posted at 2014-11-28 00:28
More screen shots

For Z-location you have X -20. According to the picture I think it should be Z -20.

Blade_Strike Posted at 2014-11-27 10:30
Change the drop down to 100% the same as others.

I would raise basic to 145 and drop atti down to  ...

Do you mind if I ask a question or two?

1.  What is the difference in the gains that DJI suggests (110, 110, and 120 on basic and 220, 220, and 120 on attitude) and the ones you are using? (145,145, and 145 on basic and 135, 135, and 140 on attitude)

2.  Do the lower #s make the aircraft easier to control, i.e. not as jumpy?  What about the automatic corrections in wind, does the aircraft still correct itself as well as it does with the higher gain settings in wind?

Thanks in advance for your help.

rubenmail@gmail Posted at 2014-11-27 11:24
Fantastic.
So this should be the correct setting? :-D

Blade_Strike: For IMU location on the screen shot; Does the X -10cm refer to the fact that the IMU is 10 cm behind the center of the plate as depicted in 27-Nov-14 5-52-33 PM.jpg?  For the GPS location does X -20 refer to the length of the mast?  If not, can you briefly tell me what they mean or point me to a resource that explains it?  Thanks and take care.

rubenmail@gmail Posted at 2014-11-27 11:27
Blade_strike : I agree :-D

So like this?

Yes, that's correct.

Reini Posted at 2015-6-6 02:30
For Z-location you have X -20. According to the picture I think it should be Z -20.

Z is below the craft, X is correct if we are talking CoG to center of IMU. Green is negative since it's at the rear of the craft.

henry@discoverm Posted at 2015-10-2 11:42
Do you mind if I ask a question or two?

1.  What is the difference in the gains that DJI suggests ...

The gains they suggested at least for me made the craft very loose for me. So I upped the basic to make the craft feel more locked in. Then decreased the ATTI so it wouldn't be so twitchy.

Gains can very from elevation, humidity and temp. Different gains will be use for smaller or bigger craft. This is why gains are always a suggestion and never fact.

Just remember if the craft feels really loose and unstable up the basic. If you want a snappier response for the stick or for correction, up the ATTI.

henry@discoverm Posted at 2015-10-2 11:51
Blade_Strike: For IMU location on the screen shot; Does the X -10cm refer to the fact that the IMU ...

If the IMU measures -10 from center of craft to center of IMU, Yes this is correct.

The X is a horizontal axis of the craft's GPS location. Since it's dead center it's 0. Now the Z would be a measurement  from center of puck to the Z axis c of g ( vertical axis of the craft). This is dependent on what battery and other hardware is hanging from under the craft. Mine is right about the top of the RED warning stick on the LG, on my s1000. So I want to say my setting is about -30.

DJI-BladeStrike Posted at 2015-10-2 14:27
The gains they suggested at least for me made the craft very loose for me. So I upped the basic to ...

Thank you.  Sincerely appreciate the info and your time.

DJI-BladeStrike Posted at 2015-10-2 14:34
If the IMU measures -10 from center of craft to center of IMU, Yes this is correct.

The X is a ho ...

Thanks again for taking the time to help.  My IMU is placed exactly like the picture above in this thread posted by Rubenmail on post #7.  Directly to the rear of center.  If it was the exact opposite, to the front of center, and the distance to the center of the imu was 10 cm, would that be +10 cm?  Thanks again.

henry@discoverm Posted at 2015-10-3 06:14
Thanks again for taking the time to help.  My IMU is placed exactly like the picture above in this ...

Yes, red = positive and green = negative.

DJI-BladeStrike Posted at 2015-10-2 14:34
If the IMU measures -10 from center of craft to center of IMU, Yes this is correct.

The X is a ho ...

The charts in the manual are beginning to make sense.  Thanks for the explanation.

DJI-BladeStrike Posted at 2015-10-2 18:20
Yes, red = positive and green = negative.

Mr. BladeStrike:  Your replies helped a lot.  I am flying a DJI S900 with Zenmuse Gimbal and Panasonic GH4 with lightbridge set up for single operator.  We occasionally do dual operater.  I adjusted the imu and gps to the actual measured values and adjusted the gains.  I tried the numbers you suggested on a windy day, today, (8 - 10 mph) with gusts and I observed that the wind seemed to rock the aircraft more at the lower attitude pitch and roll #s than when I used DJI's suggested settings of 220.  I wound up in between your settings and DJI's per the attached screenshot and think the aircraft flew pretty well.  Do the higher Attitude Settings for pitch and roll make it react quicker in wind?  That is how it appeared to me.  Cheers.