Hi.
I have a problem after updating AC to 3.2.1 from 3.1.5.
When in Loiter, the the speed of the motors rev up and down/pulsate quite rapidly. This was working fine when I was using previous versions of arducopter.
I have downloaded the logs, and have looked into accX, accY and accZ. These seems to be inside the range specified in the wiki at arducopter. (Log_vibrations.bin)
Please have a look at the Log.bin, and note the difference between ThrIn and ThrOut when I'm in Loiter mode.
Anyone having any idea what the problem may be?
Replies
I remember that on APM there was recommendation to add a Cap on one of the channels to reduce VCC spikes.
Any recommendations or process on the Pixhawk ?
Hi Tsahi
The power supply issues are supposed to be solved. However I notice the APM 2.7 has a 150uf filter cap. If you look in the log at VCC you see a lot of spikes. I have added a 2200uf 16volt cap across the 5.3 volt output in the APM power bec and covered it with heat shrink. I then looked in the log again and noticed a marked decrease of spikes so I believe its worth the effort.
Cheers Henny
Hi Henny,
do you know if its also possible / recommended on pixhawk as well ?
Thanks LTMNO for looking at my log. Been working on vibrations just had a test flight
and vibrations are better but AltHld still not good. This is my third build and never had this much problem. This frame looks like a TBS but is not TBS. APM 2.6 (frame type set to V)
810Kv 10x4.5 3 cell 3.2.1 FW PS: crash was just a tip over.
2015-04-19 13-06-24.log
It will be pretty hard to get rid of vibrations with 810kV + 10x4.5 + 3 cell.
I have 850kV motors + 4S and still rpm's are not high enough to keep vibrations in lower harmonics.
How much does your copter weight?
@Marko
Right now its about 4 Lb. I want to put gimbal and GoPro on board that will make it 4.5Lb.
All my other build are 1000Kv with same 10x4.5 and 3 cell. You might be right ! I was looking at 11x4.7 props (my ESC are only good to 3 cell) I do need to set Mid_Thr up some more I have it at 550 now needs to go to 600. I might have to rethink this build.
Thanks...............
Well, I got regular X with 850kV + 10x4.5 + 4s 3000mAh, loaded with gimbal + gopro2 + alexmos controller + separate camera and all telemtery + video stuff + separate FPV battery 800mAh. In total it's about 3.5 lbs.
I think yours it a bit overweight for loadout. Maybe you should take a bit lighter battery?
I use a 3300ma battery. So you have the same problem as everyone else here?
If so have you been able to find a fix ?
3.5lbs is very lite for that set up . The key must be 4 cell
Well, partially.
I got rid of most vibrations, but still performance of copter it not as good as on 3.1.5 firmware.
There was clue described in this article here, but I haven't tested it yet.
On the other hand, on tricopter (5x3 2900kv 800mAh) I have no such awful drift problem. Yes, it can change height if you intend to leave it hanging for some time (like about minute), but basically it flies well. I can not test "loiter" mode on it because it has no GPS, but "AltHold" is pretty good.
Key to good copter is in "coptercalc". ;)
Hello All,
after restoring the 3.1.5 firmware and setting the Throttle Accel to :
And I slightly decrease the Stab R/P to 3.5 for my 330 Hex Thorax Frame.
I am running APM Mini 2.7.2 with :
2300KV Tiger Motors
S12A ESC
5x4.5 HQ Props
External GPS/Compass
Everything is Calibrated and within Parameters...
Attached is Flight 1 with Default 3.1.5 Settings and the second Flight has modified Config as shown in picture above.
The Hex looks as follows,
This is my 7th, build and first time experiencing problems like this. That being said, I have noticed some interesting results with Battery Readings... if someone has a moment to have a look, it would be greatly appreciated.
Cheers!
Flight_1.log
Flight_2.log