AltHold shake the copter


I try to setup a 500 class heli with fly bar, the apm is on silent block, for the stabilisation it seems to be ok, but sometimes it woobles at the end of the battery, I suppose not enough throttle.
Now I’m trying the Althold, but every time I engage it, the copter is shaked up and down like the PID is to strong, but all my values are at the minimum.

There are my tries on the log file.

Could you help me please, i’m stuck.

I had the same issue on 450 heli - I suggest to decrease THR pids bellow limit values from Mission Planner by Full Parameter List menu.
My values for example:


I didn’t look at the list param, is it a bug in mission planner that we can’t go below these values ?

I’ll try your advice, thanks.

Can you fly well in loiter/poshold mode ?

Hi Guys,
Here is what I have so far, alt hold has only been bench tested and appears to work properly…
Thr_Accel D 0
" " I 1.0
" " P .5
" " Imax 50% = 500??
" " Alt P 1.0
" " DZ 10
" " Mid 553
" " rate P 6
Hope this helps :slight_smile:

Duh! This is on a blade 600x FBL (forgot to put that in)…

Yes, I do. Last days I’ve even successfully tested my first missions in auto mode.

Anyway, I still need to solve some small issues like:

  1. parameters tuning for loiter/poshold
  2. heli doesn’t disarm after autoland

I’m waiting now for new spare swashplate, because my original one on DFC head is a bit excentric which causes vibrations - no problem for Stabilise or AltHold, but problem for camera mount and possibly for bugs above.