This post is about the weird bouncing/out-of-control issue that some Spark flyers occasionally see at takeoff.  I do have this problem sometimes, and would love to hear from others with the same complaint.  Meantime, I have become convinced it's heat/weather/sunshine related.  I'll explain:

Had the Spark for almost a year and I fly it every few days.  Sometimes, and I mean just SOMETIMES...maybe every 10th flight at takeoff, the quad will bounce and jump, the motors will rev up-and-down, and respond very sluggishly to the remote sticks.  As I read it, it's a problem not unknown to DJI and many Spark users.  (Addressed in the "nyut-nyut" YouTube video)  However, I've noticed that it never happens on the first flight of the day.  If it does occur, it will be on the second or third battery...when the machine has worked up a higher temperature.  Also, I live in Atlanta, and almost always fly on bright, sunny, very hot days.  I've conditioned myself to cautiously expect the problem to happen.  I'm ready for it, and get the thing down ASAP if the bouncing and weird activity starts.

Usually I'll land it immediately, and troubleshoot.  But once, a few weeks ago, I was alone in wide-open grassy area, and the bouncing started at takeoff.  I thought, what the hell...I'll struggle to keep it flying, and see if it resolves itself.  And it did!  It flew erratically side-to-side, up-and-down, RPMs going all over the place, with almost no control.  Then after about 20 excruciating seconds of that awful behavior, it suddenly just stabilized and flew properly.  I went through the rest of the battery and another with no issues at all.

THEN!  Last week I took the drone with me on a trip out west...New Mexico.  The days and evenings in the desert were cool (coldest I've been with the drone) and the sky was overcast for three straight days.  No sun, just grey.  I probably flew through 30 batteries, and the takeoff problem did not happen even once.  Smooth, issue-free takeoff every time.  I had a blast flying in the open desert with no trees or buildings or people, and the Spark performed brilliantly 100% of the time.

So....thoughts?  The bouncing/power weirdness happens for me every few flights here in Atlanta, where it's only out in hot/sunny/bright conditions.  Did not happen AT ALL in New Mexico, where it was much cooler and overcast.  Is there anything to my heat/sun theory?

And please don't advise me to update/calibrate anything or switch the props.  I've done all that.  I've had quads for years (this one is my favorite) and I've been all over the obvious stuff already.

Any input is appreciated.

(And here's a photo from NM!)

NM_spark

The bouncing action during lift off or landing is happening becos of downward sensor action or result. There is no other component acts during this movement of the SPARK. I fear that two software algorithims are written during SPARK landing . One while we do it manually and the other code during RTH. Why i blame software coding is becos this started after the latest updates. !! and also there is no indication inthe DJI GO 4 app on a hardware failure.

ofcourse ESC motors are ruled out which can cause this issue because the SPARK flies well after a certain minimum height of 2 meters.So it cant be the ESC motors.

I had this jumping around issue too this summer and am convinced that it is heat related because without changing anything this bouncing stopped as soon as it got cooler outside.

Hmm. As a software developer, I would take a report like this as a clue to what the problem really might be.

As a Fast Food employee, I get in trouble for figuring out what the problem might be.

DoseMitAussicht Posted at 2018-10-26 20:02
I had this jumping around issue too this summer and am convinced that it is heat related because without changing anything this bouncing stopped as soon as it got cooler outside.

this bouncing effect also comes with a failure in front obstacle sensor. Have you noticed this point ?

S.J Posted at 2018-10-27 10:47
this bouncing effect also comes with a failure in front obstacle sensor. Have you noticed this point ?

No I didn't. I was not able to fly higher than 5 cm.

Had a similar issue but it was phone related - android phone would get too hot and I would get erratic behavior- placed a cooling pad on the phone no issues.

I’ve only seen the drone too hot a couple of times - then I get 4 blinking red lights but no erratic behavior.

This while flying in the desert around Las Vegas 110-120 degree temps.

For me the phone seems to be the part to worry most about getting too hot.

Just my experience

No one has written here in a long time, but now unfortunately he is doing the same for me, and even worse!
The first incident happened late last summer: He took off uncertainly during a takeoff, as if he didn’t have enough strength. Then the problem disappeared. After 3 minutes of flying, I wanted to ascend, at which point he began to descend quickly without request, did not respond to anything, and landing in an unsuitable place, all the rotors broke. There were no error messages in the flight log!
I ordered new rotors and tried again yesterday.
Unfortunately, it had already fluctuated as it took off. In flight, when I pushed the stick up, it started to fall and then only then rose, sometimes unable to rise. After a short flight, he started to land from a height of 20m, very quickly. Luckily I was careful and it happened in the middle of a soccer field and it fell into the grass. He turned on his back, but it didn't hurt.
This could be some kind of power supply problem because I didn’t update the firmware and didn’t change anything and yet the problem came up as it did for others. I tried several batteries and the same error, so there is no error in the battery, or then all 3pcs became faulty.
I think oxidation, contact fault may be in the background.
It would be nice if the DJI would say anything about this because it no longer manufactures, the warranty is no longer there, I want to fix it because I don’t want to throw it away.