0% compassmot...I'm either good...or making a huge error somewhere

Wow - I thought 4% was good for my big quad, but my FPV/trainer rig just hit the ball out the park!


- TBS Disco version 1.3 with "Core" (inc the worst screws ever to come out of china btw)

- APM 2.5+ with double moongel corners

- APM power module

- External "2.6" GPS

- DJI riser (cut to 5cm...c'mon 3DR, some longer wires for the new unit please!)

- Rctimer Simonk 30A OPTO escs with one twist in power cable and shortened to 3cm before soldering

- Spektrum AR8000 (telemetry disconnected this time)

- T-Motor 2216-11's

- Unbalanced Graupeur e-power 1050 props (will upgrade to CF once flight tuning is done)

- Immersionrc 5.8 25mwW + bluebeam (yes, that's *way* underpowered!)

- 433mhz 3DR telemetry

- Nano-tech 5000mAh 3S.

I ran the test as recommended, on Current, and I ran it to full stick.

I'm now paranoid that I've not set this up right; I did have to use a different voltage divider to get the volts to read correctly in MP. And now I'm panicking that this has mucked up the compassmot calibration!

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And he here is...with his steroid-taking satanic offspring!

I bet you just took off props instead of reversing them to push the quad to the ground. :)

I was going to say everything looked fine but then I read you did something about voltage dividers. I have no idea what that even means so I'll stay out of it. :)

Either way my standard F450 frame w/ just Zeal on my APM 2.5 bare board and I get a compassmot score of 26% and it flies autonomously wonderfully. 

Why not just test it out to see what happens? Before I got the Zeal I had a compassmot score of 92% but auto, loiter and circle modes still all worked great with wonderful accuracy. 

All i'm saying is its not all in the numbers. Go and fly! :)

Lol - yeah this is my reason for being paranoid - ive no idea if the (small) change in dividers did anything. Will do the PID tuning today and maiden it - we'll know then!

...but of course it's started raining...:-(

Ok, so I'm official brilliant and utterly stupid...at the same time.

1. Reason my volts were way out? I still had JP1 in, even though I'm powering this from the 3DR module. This APM came off a UBEC-equipped quad, and I forgot to remove the JP1. Facepalms all round. Voltage divider were removed/set to default for step two, but set to 10.5 back on the bench.

2. I fixed this, and naturally had to rerun compassmot. Which I did. Three times. And.....

...all 0% again! High fives all round.

Took it for a test flight, and all the anomolies normall seen with high %age compassmot value were nonexistent. I had to tune down the PID's a bit - to 0.145P - 0I - 0.008D on pitch and roll and up to 0.24 on yaw. However, none of this could compensate for the massive elephant in the room...the utter failure that is the COG.

I'm talking 70% trim just to hold level on pitch failure on COG. I'm running a 5000mAh 3S, and although it meets the TBS weight criteria, the COG is massively off, even with a GoPro2 loaded up front. Even when my CCD camera arrives, that'll barely help. I need to drastically increase front weight, or decrease the weight at the rear (my preferred option).

Of course, any configs I can do in the params would be appreciated as well; I'd prefer to run my sticks without trim.

Looking for suggestions on 3S batteries that take the weight forward? Are there 3S packs that are taller, not longer?

And this is it! (PS - ignore the whip on the 5.8; a bluebeam is onroute)

Vibes from first half of PID tune/maiden. Second half looks the same. A strange, unscheduled land event again...but vibes look ok:

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