Servo travel limits

[scottmacintyre]

I have searched but only found a partial answer to this: When the calibration is performed and the total range of travel is established is the software still capable of driving the servo past these limits ? If so, is there a good reason for this not to be a software limit ? Just noticed a 180 degree movement without the controls hooked up (on the ground so no pitch/roll change achieved) - this was despite a 90 degree range achieved in calibration.

 

[Raymo]

Your flight controls should have hard limits that, with proper setup of the servo, avoid any chance of the software going beyond those limits. You can also, optionally, install the limiting bracket provided with the servo.

 

[rvator51]

I set my AP servo limits to use as much servo arm movement as possible and had hard stops both ways on ailerons. Everything seems to work good but in testing I slapped the stick left to right hard to simulate a really fast jerk on the stick. My servo arm went over center and locked up the stick. That really scared me so I reduced the travel on the servo arm as well as installed the limiting bracket on the servo.

 

[scottmacintyre]

Thanks for the input. I just find it surprising that the software will allow the servo to try and move past the 'calibrated' extremes of travel and therefore rely on the hardware stops of the controls. I am aware these will prevent over-travel and the supplied limiting bracket as a further last resort. I have no intention of installing in such a way that over-centre positions are possible and intend keeping within the 60 degree range of travel as recommended by Dynon.

 

[Dynon]

Let's put it another way: The servos don't actually calibrate the extremes. They calibrate what direction is the correct movement, and check that you don't have too much movement that can be dangerous. At any given moment, they don't know absolute control position.