Wow!  What an adrenaline rush!  After some more tuning, I felt comfortable to get my heli some real flying, Since I just had a sonar installed and the sonar numbers looked fine from the console test, I took her out for some Attitude Hold (AH) test.  I've read so much that the AH could have quite a bit of error so I took her up above my roof and hover there.

 

My backyard is real small and surrounded by trees.  Above my roof is the only viable place.

After hover a bit, I enabled the AH.  It seemed to be doing well, and all of a sudden, it dropped like a stone and I immediately throttle up and fight against the AH for a bit.  Then tried to let it hold again.  And it still drop like that a few times.  Quite scary.  lol.

 

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Ah, the MB1260...  That's the one I used, and I almost wonder if it's *too* sensitive.  It was very hard to get a good reading from it, so I've gone to the MB1200.

     Robert pointed me at your post and you have a bit of an offset between your desired roll (or pitch) and the actual roll (or pitch).

    You can see it in the graph below of your desired pitch (red) and the actual pitch (green).  The gap between them is unusual.  I notice you have your stabilize roll and pitch I terms as zero.  Could you try increasing that a bit.  Keep your IMAX low though (like 1 or 2).

 

     I think Robert has already told you about the issue with your sonar but just to prove it.  Have a look at this graph of your sonar (green) and the altitude hold's output.  You can see a lot of spikes downwards from the sonar and at the same time a spike up from the navigation controller.   There are instructions for ensuring your sonar is free of EMI and power line noise on the wiki.

 

     Good luck.

-Randy

Randy, I had suggested him to set his I terms to zero, as that's what I found worked best for me.  Maybe because I have a FB, and he is FBL, there's a difference?  It's worth a shot anyway.

On the sonar, that doesn't look like the typical noise that I'm used to seeing.  Mine would usually have very very vertical spikes of noise.  His definitely have slope.  That's why I assumed his were being caused by actual things being sensed on the ground.

Oops.  First crash.  

 

Was trying to hover using the sonar again, but this time on a flat ground to make sure it is not EM spikes.  The APM insist on climbing up.  Before it hit the branches on a very tall tree up there, I tried to lower the throttle to get it down, but it was still using pitch to climb.  So I hit the throttle hold and try to auto it down, but the APM was doing some other control and got the heli spinning.  Not to mention I forgot it was already using the pitch to tried to climb.  I had no more pitch control to slow it's decent.  Lesson learn.  Should have shut off the Attitude hold instead...

Yes, you should always have an ability to go into Stab very quickly as a bail-out.  Hopefully not much damage.

Looks like only the umbrella gears in the front for the tail torque tube assembly is striped.  It is always that part that stripe for any crash for a 450 Pro V2.  If only I have a belt driven tail, it would have had no demage... maybe.  :D   Usually the main shaft would bend as well.  I'll check that once I got the tail fixed.

 

I just tried to download the logs but there is only 1 log in there and I flew 3 sessions with battery changes.  First session was playing with the Stab I starting from 0 to around 0.2.  Set the Stab I, do the auto_trim, hover a little.  Increased the Stab I, do the auto_trim, hover, and repeat.  Second session was trying the Stab I from 0.2 and up and then back down and see what happened.  Also tried a bit of attitude hold near the end.  The 3rd session was short lived because of the crash.

 

So, how is the log saved?  Could all 3 sessions all in the same file?  I have that only file attached.

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If you disconnected all power from the APM when you changed batteries, then you should have 3 logs.  I can change my motor batts without disconnecting the separate radio batt, so I usually only have 1 log per session.  

Or, if the flash memory got full, then I think it would wrap, over-righting old logs.  But that shouldn't happen unless you're doing some really high rate logging?

No, just the default rate logging.  I don't even know how to change it.  :D

 

Before these 3 sessions, I erased all the logs before I went out, just to make sure I dont' have them mixed up.  Weird...

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