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New Mavic - Calibrate IMU?
793 10 2018-5-15
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LeafPeeper
Second Officer
Flight distance : 377736 ft
United States
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Guys -
   I know there have been a ton of threads on this, and I THINK this one is a little different.  If not, my sincerest apologies.   I bought a Mavic Pro to replace the one currently dangling 60 feet off the ground in a tree.   I know I need to cal the compass before flying, but I'm torn on the IMU.

On my first Mavic, it was ROCK solid until I started calibrating the IMU myself.  I was using a solid, level surface, checking it with a level, being very still, etc, and I was getting accelerometer and gyro readings all the way around at .000 to .002.  I was pretty impressed with myself - but I still had yaw drift issues.

This one just arrived, and it looks like the first accelerometer and gyro are reading about .014 and .007, while the redundant ones are in the .002 - .003 range.   Frankly, I don't like the delta...and I also don't know if some drones have a natural delta between the sensors.   My gut tells me to calibrate before flying for the first time, but I'm afraid I might induce yaw drift.

How do those numbers sound?   Since they are still in the green/excellent range, should I fly without calibrating?

Just looking for opinions...
Thanks,
LP
2018-5-15
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Bill B
First Officer
Flight distance : 319245 ft
United States
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Yes, do the calibration. Make sure it is done on a fairly level table. It’s quick to do, and makes a big difference. Try this, go hover the mavic before doing the cali , then land, shut it down, go inside and do the IMU Cali. Go back outside and start up, hover again, bet you see a difference. The difference will be a more solid hover. Try it. Remember too that the firmware is better than ever and I wouldn’t put much stock in the experience you had with the first mavic.
2018-5-15
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LeafPeeper
Second Officer
Flight distance : 377736 ft
United States
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Well my first Mavic was running the latest firmware, although it was a slightly older unit (April 2017).   This one is dated August 2017 according to the SN decoder....and there were some threads indicating there may be some differences.   My first one just had trouble staying still after an intentional yaw.   Lots of videos here show others with exactly the same problem.  I just don't want to create a problem where none would exist if I didn't do the cal.  I think I'll do what you said - try it without the cal, then shut it down and do the cal.

Thanks -
LP
2018-5-15
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Suren
Captain
Flight distance : 7838970 ft
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South Africa
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Agree with Bill that you need to do the IMU cal but do it when the Pro is cold and not how, let it cool down properly if flying first to do a test.
2018-5-15
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GrahamG
Second Officer
Flight distance : 73369 ft
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If it doesn’t ask you to I would leave it alone. I’ve never calibrated anything on mine, flys like a dream.
2018-5-15
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DJI Diana
Administrator
Flight distance : 2408 ft

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LeafPeeper Posted at 2018-5-15 17:17
Well my first Mavic was running the latest firmware, although it was a slightly older unit (April 2017).   This one is dated August 2017 according to the SN decoder....and there were some threads indicating there may be some differences.   My first one just had trouble staying still after an intentional yaw.   Lots of videos here show others with exactly the same problem.  I just don't want to create a problem where none would exist if I didn't do the cal.  I think I'll do what you said - try it without the cal, then shut it down and do the cal.

Thanks -

Hi LP, Bill is correct, you are recommended to do the calibration, hope you have a good time on flying your new drone.  
2018-5-16
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LeafPeeper
Second Officer
Flight distance : 377736 ft
United States
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Ok - I did the cal and the numbers dropped to .002-.003 for the accelerometers and .001 for the gyros - and the delta between the primary and secondary sensors is gone.   I haven't been able to fly yet due to the weather....hopefully tomorrow.

For what it's worth, this new drone also has a level gimbal out of the box.   My other one ALWAYS required a manual roll setting of about .7.    Frankly, I'm actually surprised at the differences between the build from April 2017 and Aug 2017.   For example:

- My April build drone had a much quieter fan in the remote.   The new one is significantly louder
- The new remote has some light leakage at the bottom of the display, the old one was completely dark
- The first step in the IMU cal on the new Mavic takes significantly longer every time - my old one only took a long time occasionally
- The new mavic has a much tighter fitting gimbal clamp, and my silicone contact protector fits tighter
- The factory gimbal dome fits tighter and feels like a thicker plastic than my old one
- The hind legs sit SLIGHTLY more level with low noise props installed
- The new one came with a Sandisk Extreme microSD card, while the old one came with a Panasonic
- I THINK the new Mavic just feels a little 'tighter'.

LP
2018-5-16
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Jos A
Captain
Flight distance : 11588 ft
Netherlands
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GrahamG Posted at 2018-5-15 21:56
If it doesn’t ask you to I would leave it alone. I’ve never calibrated anything on mine, flys like a dream.

Me too, don't do it
2018-5-17
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LeafPeeper
Second Officer
Flight distance : 377736 ft
United States
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Well as mentioned above, I did it anyway...and I am happy with the numbers.  I flew this one for the first time today, and it went well.  It does have the yaw drift just like my other one, and I guess since I did the cal I can't really tell if it was the cal that caused it.  It was pretty windy today, so that could have been part of it.   It flies exactly like my other one, but I think the camera is a little better - it's actually clearer in all the corners.

I guess I'm happy.  I'm now willing to bet you that under the same conditions, they'd all have the yaw drift I'm seeing - and by same conditions, I mean same location, cal, wind conditions, etc.

LP   
2018-5-17
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G_Sig
Captain
Flight distance : 6688730 ft
Iceland
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LeafPeeper Posted at 2018-5-16 17:22
Ok - I did the cal and the numbers dropped to .002-.003 for the accelerometers and .001 for the gyros - and the delta between the primary and secondary sensors is gone.   I haven't been able to fly yet due to the weather....hopefully tomorrow.

For what it's worth, this new drone also has a level gimbal out of the box.   My other one ALWAYS required a manual roll setting of about .7.    Frankly, I'm actually surprised at the differences between the build from April 2017 and Aug 2017.   For example:

Just to clear things up. You are talking about MPP not MP?
As you use low noise props which are for MPP.
2018-5-17
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LeafPeeper
Second Officer
Flight distance : 377736 ft
United States
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No, I am only talking about the MP.  My comparison was simply based on build dates.   I am using low noise props, but they are compatible with the MP and work just fine.

LP
2018-5-18
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