Quad Freaking Out During Flips and Rolls
Okay, I’m dropping this here in hopes that someone has seen this before. Yesterday I smoked a brand new QQ190 Tank frame on its first flight since the rebuild.
While doing flips or rolls where my copter will stop sending stick commands to the copter and lock into a high-speed. From what I have been able to determine this only happens if I perform a flip or a barrel roll. I have been able to fly race style with fast acceleration and hard turns, but once I go inverted all hell breaks loose.
This (was) my QQ190 Tank. I was not flying video yesterday when it happened for the last time, but this is identical. VIDEO
This has happened during my last two flight sessions. The first time this occurred I added a new profile of slightly adjusted PIDs/Rates–after making sure the profile was stable in horizontal flight I tried acro flying and my first 360º roll never ended. The crash was light so I dusted things off and went back to my original profile and continued to fly. Back on my default profile things appeared normal until it happened again this time there was frame damage and we were done.
I rebuilt the copter(steps below) and on my first battery after shaking things out she went down again in the exact same way.
To be clear flips and rolls will cause the craft to spin out of control on the roll axis.
Trouble Shooting:
Checked all hardware for physical damage. All wiring was meter tested for common, +volts, shorts, opens. ESCs were bench checked and calibrated all checked out. FC was wiped and reprogrammed from scratch with the latest stable TBS build and PIDs were left stock. I purchased a QQ190 Tank V2 base and reinstalled everything and checked everything again.
During the freakout, my VTX, camera, LEDs still have power and are functioning and my RX is accepting disarm and failsafe commands.
Unfortunately, the build does not have a black box so the video above is all I have.
SPECS:
- Frame: QQ190 (Tank)
- FC/PDB/VTX: TBS Powercube Elite Colibri RACE v2
- ESC 20A Favourite Little Bee
- RunCam Swift Mini
- Lumenier SKITZO 2500KV
- BetaFlight (Current TBS stable build)
- Flight mode: Acro Airmode (only)
Dang, sorry to hear about the troubles. This looks like a common desync, and it can happen from time to time for a multitude of reasons.
We have noticed that more people seem to have desync issues with Betaflight 3.1.7- But it seems that if they roll back to an earilier version of Betaflight, it can resolve the issues. The only thing that we can think of is that the stock D gains increased quite a bit in 3.1.7 which could be the cause.
Can you post your pid values? Better yet, send a dump?
To do so, Go to the CLI Tab in base/cleanflight, type “dump” without the quotes
push enter.
Copy the information that gets put on the screen (highlight with mouse, right click, copy, and paste into an email by right clicking and selecting paste)
Can you tell us what props you are running?
You might also want to check the ESC firmware. We recommend updating firmware on the ESCs to the latest BLHeli Suite version. The Little Bee ESCs have been known to have issues when being pushed hard on different prop/motor combos- at least that is what we have observed on the bench. We have for that reason, decided to discontinue the little bee 20s in favor of TBS bulletproof escs because they don’t exhibit the same issues and have been very good performers in our tests.
It is very possible that your ESCs need be upgraded. Check out the bulletproof TBS escs here:
I wouldn’t expect the flight controller for now, you could try turning on expert mode in Betaflight and then observing the raw sensor data. Move the quad all around an check for an anomaly- You could also try disabling the accelerometer to rule that out. But I would start with the ESCs, and the pid values/ Betaflight settings.
Sorry guys, not sure how this posted anonymously, but it’s my question.