Tricopter flips on arm – please help!

[rc468]

That’s a battery beeper because I currently have no OSD or telemetry. Just a temporary thing and the whole build is not finalized yet. I have not even screwed all screws into the frame. I expect to receive a Matek STD board and a metal gear servo tomorrow so I will do a rebuild and will also add GPS and camera / VTX.

[Kevin_Erik]

To be honest i kept waiting for it to get sucked into a prop.

[rc468]

It won’t 🙂 I will not use it further.

[Kevin_Erik]

Just had my Tri-Mini flip on Arm!

I think that either the ESC control wires had a contact issue or the feedback / control wires for the Servo may have touched ground or each other. Had previously unplugged / reattached the Servo to change out the Tilt-Mechanisms support. Prior to this everything flew perfectly. (no wag)

Regardless, the Tri-Mini’s motor #1 was instantly at 100% throttle, launching the copter into the wall nearby. The propellers shriek was very impressive and I was glad no one else was in he room at the time. Other than the fact the Motor #1 propeller sheared completely off, the copter “appeared” to have taken no observable damage.

So yeah, this is totally possible and odds are this was due to an ESC or Servo connection on my part. I strongly suggest you either swap out the suspect ESC’s or verify them via another controller. While double checking your Servo’s wiring.

[Kevin_Erik]

Was just able to reproduce the error that caused Motor #1 to go crazy. I think it has something to do with the Servo wiring not being fully attached when the Flight Controller is expecting to see the Servo via the RSSI pad. During my little experiment the Servo was removed for this test so as to simulate what happens when the feedback wire is disconnected.

During testing, I first checked the motors individually via Betaflights motors tab. No issues and all the motors spun up in a controlled way. Next I disabled Betaflights manual control of the motors while still monitoring the Motors tab. As soon as the Copter is armed via the Taranis, Motor #1 surged to 100% throttle.

Reattaching the Servo and verifying that it still works (with smoke stopper installed) I later was able to arm the copter without motor #1 running like mad. Is it possible that the copter is reacting to the lack of the Feedback voltage by surging the motor to 100% ?

@Lauka any chance there can be a safety script added to check for the absence of the servo’s feedback voltage then either prevent arming or default the copter back to virtual so as to prevent a runaway event?

[rc468]

Had to replace my Omnibus controller because servo output went dead all of a sudden. This was my last Omnibus, had 4 of them, all died, never again. Installed Matek CTR, which also allowed me to remove PDB, flies very nice. I’ve had 26 minutes on 3s 3300 battery while flying orbital turns around me.

But now I have a little problem. When I descend fast (throttle stick almost all the way down) the tail goes down and the copter moves back with great speed. It’s absolutely like as if I pushed the pitch stick back.

First thing I thought about is the shifted center of gravity. But if copter can level itself while flying, why does not it do the same while descending? Not clear.

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