Please help fine tuning my TBS Discovery APM 2.5.

Hello all. I am having a heck of a time tuning my TBS Discovery after going from 9" e-props to 10" gemfan style props, and I'm not sure where to begin. 

I am using the Arducopter 3.2 rc2.

1 APM 2.5 on foam ear plugs on each corner, suspended inside the frame of discovery, it is mounted about 2.5" front of center of thrust on the spider quad design.

2. external mag was recently added (I have been very very confused on orientation of the compass chip. I have followed the same orientation as the APM 2.5's board)

3. Sunnysky 2212-13 980kv with 10x4 gemfan type of props that have been carefully wet sanded under water to near perfect balance with the truflight magnetic balancer.

4. 4s 5Ah battery

5. Powermodule powers the APM2.5 & minimosd's 5v side and a 5A turnigy BEC powers the LRS receiver.

6. Motor control power rail connector has been removed.

7. Afro 30A esc, all with only the signal wire hooked up.

8. Orangerx 433 OpenLRS with latest OpenLRSng

9. 5.8ghz fpv stuff, complete with minimosd. 

I have several problems.

1. Yaw is not at all locked-in in stablize mode. In acro mode, it seems to be fine, but in anything stablize or loiter, alt hold, it just wobbles everywhere.

2. Alt hold is all over the place, I can hear the motor pulsating, making alt hold plus or minus 2-3 meters. I thought the balanced motors/props would help with this.

3. I installed a external compass, thinking it may fix the yaw issue. but there isn't really a good document telling me how to orient it. I have placed the compass chip the same orientation as the apm 2.5's built in one, and I have set the orientation to "none". 

4. When starting auto way point mode, arming it on the ground, changing mode to Auto, and bumping the throttle to start its ascent to its preprogrammed first way point, the copter will completely shoot backwards ~10 meters. It has barely missed me twice (i know, i had to try it again to see if it was a gps glitch, on a separate battery), and i have no idea why it does this. RTL seems to work fine, but launch in auto is very very sketchy. 

5. certain speed in descent after successful autotune, will send it wobbling all over the place, almost crashing.

6. autotune gives me very very soft PID settings, and it is not easy to fly. My kk2 with unbalanced blades seems to fly much better.

*** I did not have any of these issues (except the wobbly yaw) with 9" props and with internal mag and the latest 3.1 arducopter firmware. It flew great with 9" props, doing some fun proximity fpv stuff. I have not checked out the vibration in the log, but the quad held by hand above my head, and full throttle, seems to have hardly no vibration compared to most of my throw around quads.***

Attached you will find my logs for the brief two flights I did this afternoon. 

If any one can analyze my logs for me and please tell me what I should do to improve my setup, that would be amazing. 

I am currently planning to go back to the latest official 3.1 firmware and test again in a few hours.

Thank you very much in advance.

2014-07-07 14-14-30 124.bin.log

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Replies

  • Did you ever get this tuned?

  • 3701776695?profile=originalThis is how I have the apm mounted. hard to see, but soft orange ear foam on each corner.

    Barometer is covered with double layer of dark foam tape. 

    • 3702502992?profile=originalThis is how I have the external compass mounted. dot is forward, with the letters trailing behind it, as some documents suggested, which is also the same orientation as the apm's built in one which I have by passed by cutting the trace. 

      FPV cam here points to the front.

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