Swash plate servo limit 1000 2000

I fly my 620 class hely since 1 year; I ever updated fw; today I notice that servo 1, 2, 3 limit cannot augmented like in arduplane: if I change limit from 1000 to other value doesn’t affect servo travel, and after reboot return to 1000; so when I use trim different of 1500, then servos travel is not simmetrical, and my course is not enought; and it may affect the pid functionality; why is not possibile to set the limit of the swash plate servos?

Because swashplate servo limits are not set in the SERVO settings in heli. They are set with the H_ parameters - COL_MIN/MID/MAX sets limits for collective, the CYC_MAX sets the cyclic limit.

Only the SERVOx_TRIM is used in heli to level the swashplate, and ideally that shouldn’t be used either - it is better to leave trim at 1500 and turn the pitch and swash linkages to adjust swash level, and to track blades.

All other servos limits and trims in heli are set with the SERVO settings, including rudder.

If all helicopters were H1 swashplate with mechanical mixer then we could set the swash limits in the SERVO library. But most helicopters are CCPM mixed, so with CCPM helicopters you are not setting the actual individual servo limits - you are making adjustments to the CCPM mixer. And that’s what the H_COL_MIN/MID/MAX and H_CYC_MAX settings do is adjust the mixer.