[Rick~K]

I got out my old Flip Sport to fly, it had the last OP release and I updated it to LP 16.09 including FW. My configuration is: Hoverthings Flip Sport, Revo w/o GPS (kickstart), HobbyKing 30A ESC 3A UBEC flashed with SimonK, NTM Prop Drive Series 28-26A 1200kv / 286w, and a 4s 4500 Lipo. I hadn't flew it in a couple years and it flew great. I've tried tuning the PIDs and can't get the oscillation to calm down even with a low P setting. I'm starting to think something hardware is causing a problem, because the oscillation never changes. Maybe a motor?

[f5soh]

Hi Rick,

Please post your config file. (File > Export UAV settings...)
This will be better to diagnose the issue.

[Rick~K]

Here it is Thanks =)

[f5soh]

That's quite strange, PID numbers used are pretty low and shouldn't give oscillations.
Nothing wrong in output configuration as well.

Can some unbalanced props cause trouble ?
Maybe give a try using Rate mode stabilization.

[Rick~K]

Yes I can try rate, tuning was tested in Attitude. I can't fly it again until first of next week, I had a cheap locknut on the prop shaft that messed the threads up and had to order a new shaft and nuts.  I noticed  when I was in GCS and plugged up to battery and props removed a couple of the esc's were warm, I never noticed that before but wasn't looking for problems then.

[TheOtherCliff]

Maybe cut the stock PIDs in half to see if that stops the oscillation.

What size props are you running?  I would guess that anything larger than 8x4 would be too big.

Do you have a lipo alarm on it?  I wonder if the battery voltage is dropping a lot under load (old battery?).

Stock PIDs should work OK.  You could try AutoTune for a second opinion.  To use AutoTune, you really should start with PIDs that don't oscillate.

[Rick~K]

I'm running 8x4.5 RCTimers and new lipo's total flight time on it was 40 min.
When I set it up I tried "current" because the "Flip Sport" has different hardware and battery. I then tried tuning that but it never changed, I went back through setup wizard and picked a frame with the closest size and hardware.  First flight was default, then I cut the PIDs to half with no change. I had the P down to 14 and still oscillation but then I started thinking maybe a hardware problem with one of the motors. The thing that bugs me is it flew fine when I parked it but that was a couple yrs ago.

[TheOtherCliff]

I see you are running GyroTau=.005  Tooltip help says the default is .005, but the default it is really .003 and running a higher GyroTau is like running slow ESCs.  It slows down the response and requires lower PIDs to make it work without oscillation.  I ran into this same issue when playing with AutoTune, but not till I used higher GyroTau than .005

You shouldn't really need a high GyroTau unless you have vibration problems that you can't fix with well balanced props.

When reducing PIDs, did you cut all three (P, I, and D) in half on all inner loop actuators (Roll, Pitch, and Yaw) on Stabilization->Bank#->Advanced for the bank# that you are using for your flight modes?  A total of 9 numbers...  That should greatly reduce oscillation associated with higher GyroTau.

[Rick~K]

I used Basic tab, when I lowered P in Inner Loop to half default I only lowered I and it was 2x P. I linked Roll and Pitch in both Inner and Outer Loop with Outer using the same P.

[TheOtherCliff]

Well first set GyroTau (Stabilization->Expert tab) to .003 and set PIDs to defaults.  I suggest using the Advanced tab to set the PIDs (and click the check box to "use Advanced" or similar wording on the Advanced tab).  I bet that will be better.

If that still oscillates, reduce all nine inner loop PID numbers on the advanced page.  Maybe reduce each one by multiplying each number by .75 and try that.  If it needs more, just multiply each number by .75 again.

[Rick~K]

Ok will try that when I get the new prop shaft.

Quick question, the presets model profiles (that's new to me) has a Flip Sport frame but the motors and battery size were not same size. How close would that be in tuning? I picked another frame that had the motor,esc's,and battery the closest.

[Rick~K]

Lowered GyroTau to .003 and reset to defaults and it flies pretty good on default. Thanks for the help!  =)

[TheOtherCliff]

That (presets / templates / cloud config / shared settings) is a topic of debate. 

The default settings work well for most quads but I recall oscillation with some large sluggish quads and less than optimal on some small high performance quads?

If you run Revo AutoTune with a fully charged battery vs. with a depleted battery you will notice a consistent numerical difference in result PIDs but maybe not in the feel.

Changing brand of props without even changing the size can need a different tune (or not).

Small 1000KV motors may do best on 9x5 props where larger 1000KV motors may do best on 10x5 props.

Weight makes a difference.  A heavy or light camera or no camera at all can change the tune.  Same with a larger or smaller battery.

One man's manual tune may not feel correct to another man.

That said, it's easy enough to give a template a try and to use it for a basis for tuning if you think you can make it better.

In the Flight Mode Switch setup you select a PID bank, so you can play with different PIDs in flight.

Since you have a Revo, the perhaps easiest? best way is to use AutoTune.
https://librepilot.atlassian.net/wiki/display/LPDOC/AutoTune

[Rick~K]

Looks like what I'll do, A lot quicker than running back to the PC.

[Rick~K]

Set up the FMS with AutoTune and it tuned just like you and the Wiki said, works just fine all but the red wasp that decided to help with my attention while it was in FMS #2 but the final PIDs were probably better than any I ever flew with trial and error tuning. I remember testing a few years ago and had both good and bad results but as I recall got back burnered.  I have to say LP has advanced with some nice things since OP.