VTOL no longer hovering

ArduPlane VTOL Plane
1

My Heewing T1 VTOL PNP (not the conversion) was hovering very well in QLOITER on my first few flights. Then, it was showing level hovering with good throttle control on all axes.

My last few hover attempts in QLOITER have all failed. With pitch fully lowered as I raise throttle, the trirotor VTOL just flips backwards. To take off, it has to be pitching forward, in which case it moves forward. But it can’t maintain a hover in-spot like it could before.

This behavior started after I crashed in my first attempt to transition from QLOITER to FBWA. Things that I’ve changed/tested to the VTOL since that crash

  • replaced one tilt rotor servo with another factory servo (though this one is a different model) and retuned the tilt rotor servo output levels
  • CoG is not a problem as it is basically unchanged
  • tried recalibrating accelerometer, compass and radio
  • reflashed arduplane to the factory 4.3.5 Heewing firmware, which was the version running when the VTOL was hovering fine
  • ran the Mission Planner motor test and all three motors seem to be throttling up fine to 50%

Any help on a fix is highly appreciated!

2

We can not help you without a .bin log file.

You should use 4.3.7 or newer. Point releases fix bugs and introduce no regression (extremely low risk due to the huge batch of regression tests, plus everybody is using them, and very few people are using 4.3.5)

1 Like
3

Unfortunately, the standard flight controller on this PNP does not allow logging as far as I know. It’s based on the F405 but does not have an SD card slot.

And the manual for the PNP specifically says to first get the VTOL working using the stock 4.3.5 firmware… QLOITER was working perfectly with the factory setup until my crash, and I’ve been unable to upgrade to 4.4.0 despite following these instructions by @hwurzburg.

4

I think ArduCopter 4.4.0 can log on boards without an SDcard, if configured to do so.
Are you willing to try it out, and configure it to do that?

5

I just updated my reply above as you were responding. I can try again to update to 4.4.0 again, but earlier I could not get a working firmware version based on that post.

6

As @amilcarlucas says all supported board that I am aware of w/o an Sd card will Block log. What is LOG_BACKEND_TYPE set to?

7

This one will not…it has no SD nor SPI flash…so users are a bit hosed…I understand they are planning a V2 with SD card…many have taken the OEM controller out and replaced it with a fully functioning one(ie that has logging capability)

3 Likes
8

How about Mavlink backend? Set telemetry to maximum baud and hope for the best :slight_smile:

Mavproxy data flash logger here

9

please show the link to an add on, standalone logger, to attach to a serial port with MAVLink output…dont know of one

10

If it helps, I just tried calibrating the ESCs and noticed something unusual about the motors spinning. Redoing the Mission Planner motor test, the front two motors hit their max rpm at about 50%. They maintain the same rpm (gauging by the frequency of the sound made) up to 98%.

The rear motor increases rpm all the way up to 100%.

This is really strange. Because my T1 PNP tends to generate more lift from the front motors during QLOITER, I thought the rear motor is not spinning up to 100% throttle. That seems to be wrong.

Wondering if there is an issue with power delivery…

Re: 4.4.0 I can’t seem to install it as per my comment above.