Another Divergence Problem AQ FW R340....

[Max]

[teramax]

[Max]

ESC reaction time could certainly affect the result (if it is the limiting factor). And an overshooting does seem to indicate a propulsion system which is quicker to react, like the Porsche.

-Max

[LPR]

[teramax]

James, for 3Kg and the 3110-17 i would recomand 11x4.5 or 12x3.8 but generaly i notices in the past that if you want a very agile system you wanna use higher pitch.
i.e. best performance i had with the Graupners 11x5 but less eficiency and propper tuning became more important.
For a realy extremly smooth system the lower the pitch of the props the better but yea, the lower the pitch the faster the RPM changes have to be from the motors.
Low pitch props also work like a dampener for the system, they are more forgiving on wrong gains, exept divergence problems.

no phsical reference, only my observations

[Jdmagoo]

[Jdmagoo]

[teramax]

On the Hex, i drove the MT2216 900kV with the 10x5 Graupners and the Wooden 11x4 Gemfans, yes i had little Yaw problems but never tried to tune them out.
But never had this divergence thing there and yes i´ve pushed em very hard.

On the X8 divergence is just a little noticable but i never lost kontroll on it.
Like Max mentioned i believe with a little more time for tuning on the X8 i could completly eliminate this for ever.

Your observations about the RCT 11x5.5 i can confirm, in fact they look identicaly to the old tiger 11x4.5 but yea, the are not that precise.
I fly on the r0sewhite Rubina the RCT 8x5.5 Tiger clones and i got them balanzed with some ornate tricks
I would also try the Tiger 8x3.8 just to compare but meanwhile i need a sponsor, thought

to summ up i would say, the more pitch, the more controll u archieve for your configuration, the less problems occur.

[Jdmagoo]

It does sound like divergence is a real problem for AQ and probably something that should be addressed as priority over other features.

The end user can obviously ensure they have the correct motor and prop combo for their frame, but after that they should have a level of confidence in the FC not creating divergence. Would introducing another PID parameter be the answer, or is funky coding in firmware required?

For me, the 11x3.7 props will arrive tomorrow and will set up a jig over the weekend (like Menno's tuning vids) and try to recreate the divergence problem. Understanding these props are probably not correct for my setup but will see what I can achieve with PID tuning.

I will then wait for the RCTIMER props to arrive and repeat the above procedure.

I guess I could replace the motors with MN3510 700kv and use 12x4 props that should give me the required thrust at hover and perhaps? prevent the divergence problem.

[Jdmagoo]

Well i increased the roll Pid from 50 to 80 and reduced tilt rate D from 34600 to 30600 and the divergence still remains however, it will recover by itself and not crash. I really pushed the sticks from left to right full deflection but the craft managed to recover without crash. I even switch to manual mode and flew flat-out to the right then switch to DVH and let go of the sticks and its still didn't crash. Although it did diverge left and right until stable, but didn't go beyond its limits.

The MOT_CTRL_PITCH and ROLL are now around the +-500 mark so all good there. Unfortunately its not quite as stable in AH or PH as it was before reducing Tilt Rate D but at least it won't crash.

Anyway, I'm hoping that when i get the 12x4 TM props i can increase Tilt Rate d again.