Noob needs help!

ArduCopter Copter 3.2
1

I have a FliteTest electrohub quad that I am converting from a multi wiii flip 1.5 into a APM. I would like to set it up as an AP rig. I have a 250 fpv quad that runs Naze 32 and I have that dialed in so I think I have some handle on different boards and getting them working.

It flew fine before and I am having troubles getting the APM setup. This post will be long winded, but I want to give as much info as I can to help with the diagnosis.

When I first set up it would flip right away on takeoff. Solved that by double checking all connections, motor directions, and recalibrating esc. Must have had something wrong because now I can takeoff.

The next issue was getting it stable after takeoff. I used Chan 6 for pid tuning and was able to get it flying with reasonable stability.

Now on to auto tune to get it dialed in. Yesterday i had started auto tune but it didn’t do much. I had to keep making corrections to keep the quad away from things so I ran out of battery before it had a chance to start with pitch tuning. (I checked my pids after this flight and they were the same as before.)

I decided i needed to try auto trim first to get to stay in one spot before trying auto tune again and this is where the real problems start. I read up on auto trim and the wiki said save trim was a simpler option so that is what I set up.

Today when i went to takeoff it flipped forward immediately. My fault as I still had it in alt hold from yesterday’s auto tune session. Back to stab mode and try again. Takeoff is good and I try to hold it in one spot and adjust the trims for that. I landed saved the trims and then took off to try the new trims. It seems better so I land and change batteries so I have a fresh one to do auto tune with. When i takeoff again it is all over the place. It wants to do everything but stay still. Its will pitch front and back, roll left and right and even yaw is not stable. The only thing that is working alt hold so I don’t have to worry about that when I’m trying to keep form crashing. The quad drifts around not really responding to my inputs as quickly as before, and then just drops from the sky from about 15 ft. and lands upside down breaking 2 props and the gps mast.

I decided that was enough for the day and went back inside to try to make sense of the logs. All I could find were batt fail-safes but they don’t make sense because they are set at the same voltage as my lipo monitor that plugs in the balance port and it didn’t go off. When it had the Flip board I used a 2200 3s lipo and got around 12 min. flights, now with a 2200 3s I can barely get 5 min. flights. I tried a 2800 3s and am getting about 8 mins. Does the APM and telemetry use that much more or do you think I have a bad battery?

I have attached 3 logs from today, They should be the short flip on takeoff, the trim flight, and the final crash flight.

Any help would be greatly appreciated as I have no clue what went wrong.

2

This is the first I have heard about using trim to stabilize a copter. Altitude Hold will not keep a copter from drifting in the wind or just because of balance. That’s the way that mode works. Position Hold or Loiter will keep it in one place.
I have also heard that the Auto Tune function has some issues, specially with small quad copters.

As far a power goes, I don’t think it uses anymore power than any other flight controller.

Mike

3

I was using the trim save to try to keep it from drifting. It was a calm day and the quad would drift one way or another before I adjusted the trims. I couldn’t get autotune working because I had to keep correcting for the drift and I didn’t think it started until there was no stick input for a short amount of time. Before it crashed Alt hold was working as it stayed at about the same height, it was just flying very erratically.

4

You can auto tune when it is drifting. You set Alt Hold and then turn on Auto Tune. It will start as soon as there is no stick input. When it get too close to something just take control and move it back.
When you stop using the sticks it will continue.
I also read somewhere that if Trim is used then Auto Tune will not work.

Mike

5

I have been doing a lot of reading lover the last week and I think I am getting things ironed out. I think the last crash was due to a low tx voltage. It was down to 10.8V. Charged it up and have not had any similar problems when flying. I have got the AutoTune to work and it almost doubled all of my values.

Next up was getting Loiter to work. It would start to toilet-bowl and full stick corrections were required to get it to stop. I had preformed all of the compass calibrations several times and ran the compassmot. I had compass readings in the over 60% area so I set out to work on those. At first I thought it was because of the ElectroHubs entire bottom plate was a PDB. I didn’t was to replace the frame so I tried all of the easy options I could. I twisted all of the ESC power and signal wires as well as any other wires that were on the quad. Ran the compassmot again and now down to 33%.

Loiter works much better now, but there is still a small toilet-bowl. (maybe 5ft or so) Can this be corrected by changing the Loiter PID or do I need to try to get the compass down lower?

6

Toilet bowl is caused by bad magnetometer offsets(calibration-) or magnetic interference (let near high current cables)