"It´s very complicate, I agree. But It makes the difference if you want a very smooth fly.
The risk to tune the quad structure is to make a bad tunning and instead of attenuation you´re going to have amplification!! In this case is better to keep the…"

"Hello guys
A 2DOF ( Degrees of Freedom) model is better to representing the quad when you have 2 mass connected by a beam (one mass is the motors+propellers, the another mass is the center of the quad and the beam is the the structure)
see…"

"Hello guys
I had a mistake on the follow comment:"- Finally, the code (software) that you´re using to read the accelerometers and gyros signals must have a high-pass filter feature" please read low-pass filter instead of high-pass filter.
- The…"

"Hello Dan, I had a lot of experience with vibration I have some clues for you: - APC propeller are the best, even with no balancing job, they have good balancing,
- Use the original propeller holes, don´t drill it for a larger hole,
- Use motors up…"

"Hello Jordi
Now I´m sure that the problem as I had discussed at http://diydrones.com/forum/topics/hmc5843-3-axis-magnetometer?id=70...
is the 200KOhm resistor.
After I removed the 200KOhm resistor and jumped the pads, I turned back my board to 5V…"

"Hello Jordi
Yes, I believe that this problem is the same as I had discussed with Chris Anderson and others guys at this forum:
http://diydrones.com/forum/topics/hmc5843-3-axis-magnetometer?id=70...
thanks
Luís Mauro"