Distance from the GPS and IMU

[Oylore]

In this example, I measure on my S800

How do we measure distances from the GPS and IMU accurate?
I understand the + and -, but ....

Do we measure from the bottom, middle or upper side of the IMU?
Do we measure from the right, sentrum og the left side og the IMU?

The GPS is easier, there we measure from the center, I think.....

CG = carbon plate

IMU
x = -7
y = 0
z = 0

GPS (is in the senter of the CG)

x = 0
y = 0
z = -15

Se my pictures and first flight.

http://www.youtube.com/watch?v=b_kN8ClmHjo

 

[kristiaj]

From Wookong manual:

Fill in the distance between body center of IMU/GPS and the C.G. of multi rotor in X, Y & Z axles as showed in the figure.

 

[Oylore]

Thank you! Had overlooked that line

Then I have to make the Z for the IMU -1 or -2 cm.

How is the experience of going up or down to nearest integer value. Does this mean anything at all?

 

[kristiaj]

In the beginning I misunderstood the manual. My IMU is 6cm over CG, and I set IMU Z to 6 instead of -6. It still flew ok and held position pretty good. But after I corrected it to -6, it started the "toilet bowl", going round and round. I then had to change some of the X and Y values a little. It seems like some of the values are more important than others.

 

[Gunter]

I did a little video of this: