Everything is setup going in the right directions. And it always work fine the first minute or so of the flight. But then the drift start being noticeable, and after a while it gets really bad. Hovering for a while seems to make the horizon get corrected a bit again.
My setup is a stock Trex 550 X Dominator Super Combo Kit with the ESC replaced by a Hobbywing Platinum 120A V4 and the microbeast replaced by a Spirit Pro. The receiver is an FrSky X4R, and in addition to the Spirit ESC integration I have an altimeter and a cell voltage sensor installed.
The unit is installed on the platform where Align recommend to put the microbeast. With the tape that came with the unit. So it should be aligned properly. And all channels move in the right direction. I used to set the cyclic rate to 13, but I tried setting it back to 11 to check. But that made no difference. I test this every flight now, and it always fail. It start out fine, and then get progressively worse throughout the flight.
I attached my settings, and also a screenshot of the RPM and vibration log from a long test hover I did a couple of days ago:
Attachment:
File comment: Vibration Log
Trex550X vibration log.PNG [ 165.79 KiB | Viewed 992 times ]
I'm a bit puzzled by the fact that tilting the helicopter before takeoff can throw it off. Does it really try to capture the horizon at bootup and then integrate throughout the whole flight? In addition to the fact that it accumulate integration error during the flight, that is also a problem for helicopters like the 550X that are leaning forward quite a bit due to the weird landing gear (tilts forward by 5° to give better tail clearance). The microbeast did not have that restriction AFAIK, and seemed to always be able to figure out what was down on the fly by using the accelerometers and current rotation rates.