Alt_hold bouncing

I just updated my copter from 3.4 to 3.5. I flew this morning w/ 3.4 and it was smooth. After putting 3.5 on it, my copter bounces up and down in alt_hold mode. Kind of like the PID’s are wrong for alt_hold. But how do I correct that?
I can get a log if you need… But I figured maybe it’s something simple so I’ll start w/ this…


I halved the throttle p and I values, and that seems to have fixed it…
First time I’ve had to touch those settings…

I found this problem to be related to the change in INS_ACCEL_FILTER from 20 to 10 in 3.5Rc8 in my PixRacer based mini quad. Setting it back to 20 w/o any other PiD changes fixed this problem for me.

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Thanks! Not a pixracer in this copter, but it’s a small one…(250 ish).

I’ve been finding a lot, that arducopter must be developed for larger quads… I’m wondering how much longer that will be wise? Everything is getting smaller… I fly a HD camera on my 80mm quad now! Full 3 axis gimbal on my 250 size quad. It won’t be long before range finders and other mapping type capabilities are available for these small copters.
Well, I already use my 250 size quad for mapping… It’ll do anything my 650 size quad did a few years ago.

Anyway, thanks again for the advice about the filter.

Could you share a link to the 3-axis gimbal that fits on a 250 quad? I’m looking for exactly that. Thank you.

I built it myself. Some of the new small RCX gimbal motors, and a storm 32 board.
Few pieces of aluminum bar. It was surprisingly easy. (If you know a bit about gimbals and balancing them)