Originally Posted by clutch22
Hey guys. I'm having some trouble configuring my flaps with G3x and POS-12.
Most of the time my G3x system doesn't want to deploy the first notch of flaps. I will have to hold the switch down for several seconds which will bypass the predefined selections until the switch is released. Once I do this, everything works fine. It will go to all my preset flap angles. When I fully retract the flaps, the flap motor will continuously run for about 3-4 seconds until I guess the G3x times out. I'm guessing my problem is that the POS-12 sensor isn't always reaching the required voltage for reflex flap setting and so the motor keeps running until it times out. In fact, I've tried to re-calibrate the POS-12 at the reflex position a few different times. If memory serves me right each time I calibrate that position, the voltage may vary slightly from ~9.64v to ~9.50 volts. I know about the unreliable outputs that the POS-12 delivers at its extremes and I tried to stay away from those ends of the travel. I'm hesitant to try to readjust my POS-12 throw because I'm skeptical that it will fix the problem, because in the reflex position the flap is right up to the aft spar/end of flap motor travel. Therefore, the POS-12 voltage output would have to be dead-on every time for the flap motor to quit running immediately when they are retracted. And the fact that the flap motor keeps running for a few seconds, doesn't bother me, it's that the switch wont deploy them again unless I hold it down to get it to bypass.
It is probably best to contact us directly via email so we can share information more directly, but it sounds like you may be onto something with the flap position sensor.
You don't mention any issues with using zero flaps and lower, so this tells us the sensor and calibration are working well in that range.
You indicate that this is a "most of the time" problem, so this tells us that perhaps sometimes the pot settles into a location where it provides a voltage (resistance) that is too far outside the calibrated range of the sensor, so the system doesn't know where the flaps are.
When you bump the switch down to command it to move from the Reflex position to the Zero position, it doesn't know where the flap is, so doesn't risk moving it in the wrong direction.
This is just a guess since we haven't seen this before, but if you provide us with your flap position calibration table (screenshot) and show us the voltage readout for the flaps in the reflex position, perhaps we can figure out what is happening.
You might also provide some simulated air loads on the flaps when studying the output voltage in the reflex position to give us a range of observed voltages.
It may be as simple as just re-calibrating under the right conditions, or moving the sensor slightly so it doesn't run out of range before the flaps are parked in the reflex position. Of course, this might cause a full flaps problem.
To others reading, one can always hold the flap switch in the up or down position and force the flaps to move, but having an issue like you describe causes partial loss of the full automation features the GAD27 provides based on the flap position sensor input.