Well it happened. I crashed!!!

4thdpi · Feb 23, 2019

I am done with the phantom series. They have one problem every week. I will be doing an imu calibration this weekend. My p3a, lost its sanity about 300 ft from my house. Decending thru 200ft from 300 ft, I have flown phantoms for 2 years now. The problems involved requiring to sending it to dji for a repair, usually around 300 dollars. When at 50 ft I have a message go from GPS enabled to sensor problem. Straight down into a bush which protected and cushioned the fall. The drone shut off when the sensor msg displayed. No damage to it. Now it won't take off with same msg sensor problem and won't take off. I spent an hour with dji tech support with them with screen shots of sensor problem displayed. Dji responded do a imu calibration.

Help I never did one, can someone help me with the process and guide me through it. Does the imu process fix this. I'm totally mavic now. No problems. Wireless firmware updates, nice. I'm done with the phantom series. If the imu calibration works, I'm selling it. Ps I had 33% left on the approach when sensor light came on. WILL THE IMU CALIBRATION FIX THE SENSOR ERROR. Thanks everyone, this a great site to share.

Chrislaf · Feb 23, 2019

4thdpi said:
I am done with the phantom series. They have one problem every week. I will be doing an imu calibration this weekend. My p3a, lost its sanity about 300 ft from my house. Decending thru 200ft from 300 ft, I have flown phantoms for 2 years now. The problems involved requiring to sending it to dji for a repair, usually around 300 dollars. When at 50 ft I have a message go from GPS enabled to sensor problem. Straight down into a bush which protected and cushioned the fall. The drone shut off when the sensor msg displayed. No damage to it. Now it won't take off with same msg sensor problem and won't take off. I spent an hour with dji tech support with them with screen shots of sensor problem displayed. Dji responded do a imu calibration.

Help I never did one, can someone help me with the process and guide me through it. Does the imu process fix this. I'm totally mavic now. No problems. Wireless firmware updates, nice. I'm done with the phantom series. If the imu calibration works, I'm selling it. Ps I had 33% left on the approach when sensor light came on. WILL THE IMU CALIBRATION FIX THE SENSOR ERROR. Thanks everyone, this a great site to share.

The problem I’m having with my P3S is my fault as a result of me not compensating enough for tree height and crashing it. It’s not due to a defect in the drone. I’ve done over 250 flights with it and it has been rock solid.

Chris

Chrislaf · Feb 23, 2019

UPDATE:
I fixed the IMU!!! I tried the suggested methods of inserting battery firmly and banging the battery side with the palm of my hand numerous times all without success. So using the video I linked to above I opened the drone and the IMU box and did the tapping on the accelerometer. Fired it up and it worked - I could now calibrate the IMU. Put everything back together installed my spare props and did a motor start. Everything appears to work and I didn’t get any errors. Next step will be to do a short test flight.

The hardest part was separating the top shell from the bottom - DJI sure makes it hard to get in. Next was getting into the accelerometer box without breaking the clips.

All in all, very pleased I got the IMU working again, now to get a test flight done.

Chris

3rdof5 · Feb 23, 2019

Chrislaf said:
UPDATE:
I fixed the IMU!!! I tried the suggested methods of inserting battery firmly and banging the battery side with the palm of my hand numerous times all without success. So using the video I linked to above I opened the drone and the IMU box and did the tapping on the accelerometer. Fired it up and it worked - I could now calibrate the IMU. Put everything back together installed my spare props and did a motor start. Everything appears to work and I didn’t get any errors. Next step will be to do a short test flight.

The hardest part was separating the top shell from the bottom - DJI sure makes it hard to get in. Next was getting into the accelerometer box without breaking the clips.

All in all, very pleased I got the IMU working again, now to get a test flight done.

Chris

Glad to hear!!!

xspwhite · Feb 23, 2019

Glad it worked out.

Chrislaf · Feb 23, 2019

Thanks all for the words of encouragement.

I must say I was quite skeptical as to the effectiveness of tapping on the accelerometer but it worked and I'm thankful I didn't have to send my AC in for repair.

I did a short flight today to check to make sure everything was working ok and to check camera function (gimbal pitch, taking photos and video, and making sure everything stored to SD card). Everything worked perfectly. Kept the flight short and close as there was strong wind gusts. Another winter storm is coming overnight with everything (freezing rain, snow, strong winds and wide variations in temperature). There are even thunderstorms forecast for Monday, so looks like I'll be grounded for a few days. Oh well, time to break out the Tello again!

Chris

Fly Dawg · Feb 23, 2019

Chrislaf said:
So using the video I linked to above I opened the drone and the IMU box and did the tapping on the accelerometer.

Not sure of your age, but that statement reminds me of banging on the side of the TV to get the screen straight. Sometimes the odd things do work, but for the most part, only temporarily........then again? Who Knows.....

Chrislaf · Feb 23, 2019

I’m 56.
Yes, when I saw the video and read about others slamming in the battery and banging it with their hand, I never thought it would work. Hopefully, it will be more than a temporary fix. I will certainly run a check on the IMU more often now.

Chris

Chrislaf · Feb 26, 2019

Today, I ran two AutoPilot Follow Missions while I was out Nordic Skiing on the ice (snow covered). I flew two complete batteries without any problems - everything worked perfectly. The wind gusts were getting stronger so I called it a day after the 2 batteries. So far the fix is working and I haven't had any more problems with the IMU.

I feel very lucky that there was no other damage from the crash. I did find a small crack on one of the landing struts which I will fix with Bondic.

Chris

Nightwolf · Feb 26, 2019

Happy to read this. Thanks for the update

Fly Dawg · Feb 26, 2019

Chrislaf said:
So far the fix is working and I haven't had any more problems with the IMU.

If you are curious as to what you did by the tapping, I went back and looked at the accelerometer data. The impact caused the Y accelerometer to stop working. I did not look previously because the impact was so noticeable via the attitude signals.

Chrislaf · Feb 26, 2019

Fly Dawg said:
If you are curious as to what you did by the tapping, I went back and looked at the accelerometer data. The impact caused the Y accelerometer to stop working. I did not look previously because the impact was so noticeable via the attitude signals.

View attachment 108977

Thanks, that graph really illustrates the impact. Curious: What software did you use to plot the graph?

Chris