"From my not particularly rigorous testing, I'd be tempted to agree that it's an issue with the default setting for filtering.
I was having issues with AltHold (and Loiter) after upgrading to 3.2.1 after it had previously been okay. I tried…"
"I was having similar problems with throttle pulse in alt hold and lotier on my custom build Y6.
Decreasing Throttle Accel P and I values helped, but what seemed to make the most difference was decreasing throttle rate from 6 to 3."
"I think you might struggle with getting small enough custom electronics, though the KK2 Mini board from Hobbyking is quite small and you could customise the firmware.
As for multiple batteries, etc, that's just a case of having enough space on the…"
"I use mine in plane mode (I think it tells you to do this somewhere in the manual). Heli mode on the 9x automatically includes some mixes to (I think) adjust the rotor blade pitch as you throttle up. Obviously this isn't needed when you are flying…"
"It sounds to me like you have some sort of mix setup on the transmitter. You'll either have to go through all the mix settings and check they are all off, or reset the profile on the transmitter and start again from scratch."
"Nice, thanks. I've been trying to design something similar but not actually printed anything yet because I'm not convinced it will be strong enough or stable enough. Is yours fairly solid and how does it cope with vibrations?"
"In my Mission planner it is towards the end of the list called "Drift". It was a bit "funny" about appearing just after I'd upgraded to 3.1 and I had to unplug everything and turn it all off and on again for it to work."
"Thanks. That makes sense. I didn't think my explaination of yaw sounded right really :-). And your explaination does make sense because its the same as the other axes in that you set it at an angle and it stays there.
I'm pretty sure I must have…"
"Looks good, I'm looking forward to trying some of the new features in 3.1. Wrt to acro mode, I've tried it once before in 3.0.1 and it didn't seem much different to stabilise. But I was being very tentative and reading the wiki page I think I might…"