Wobbling drone - at low thrust

ArduCopter
1

Hi!

I have built a drone. Speedybee F405 V4, 60A ESC, 4S1P battery pack (21700 EVE 40PL, 70Amp cells). I have strapped the drone to a heavy piece of wood, to avoid flip-over, fly-away … It’s an expensive toy :slight_smile:
I’m planning to use the drone for photography and smooth movements. No crazy freestyle, no drone racing :slight_smile:

When I push some thrust on the RC controller, the drone sometimes start wobbling. Sometimes it’s stable, sometime it’s shaking.

Google link for my .BIN log:

Here’s a screenshot from Mission Planner log analyzer of accelerometers:

image
image1503×1110 18.9 KB

I think te battery voltage is OK, it’s not sagging unacceptable:

image
image1487×1085 11.6 KB

Can you please give me some direction where to start?
Is the drone contruction bad?
Are my PID parameters wrong?

Thank you!

My PID values are the following:

ATC_RAT_RLL_P = 0.12
ATC_RAT_RLL_I = 0.12
ATC_RAT_RLL_D = 0.006
ATC_RAT_PIT_P = 0.12
ATC_RAT_PIT_I = 0.12
ATC_RAT_PIT_D = 0.006
ATC_RAT_YAW_P = 0.15
ATC_RAT_YAW_I = 0.08
ATC_RAT_YAW_D = 0.003
ATC_ANG_RLL_P = 6.5
ATC_ANG_PIT_P = 6.5
ATC_ANG_YAW_P = 4.5
ACRO_RP_P = 4.5
ACRO_YAW_P = 3.0
ACRO_RP_RATE = 540
ACRO_YAW_RATE = 420
ACRO_TRAINER = 1
MOT_THST_EXPO = 0.65
MOT_SPIN_MIN = 0.15
MOT_SPIN_ARM = 0.10

2

The PID controller that stabilizes the aircraft won’t really work if you have it strapped to the ground because the aircraft is not free to move around like it expects. I recommend making sure you follow all the setup steps and then attempting a first flight w/o any straps/tethers/etc. I know it is scary - but as long as you follow all the setup steps correctly it should be just fine!

1 Like
3

Hi!

I have followed the mandatory hardware setup and optional hardware setup. Since my post I had changed the PID parameters according to Initial Tuning Flight — Copter documentation but I had no chance to test it on the field.

I’ll give it a test fly, when I get to outdoors.

Thanks!