pjwright

I've run into a stumper here. I'm trying to slave the left wing flap servo to the right wing flap servo so that I can independently control the direction and end points/subtrim of each flap. I have the master flap servo on channel 6, and the slave servo on channel 5 on my R6014FS (no retracts on this plane). They are both Futaba S5131 digital servos. Both servo horns are in the same relative position. Both control linkages are the same length. Both flap horns are the same height. Both servos travel roughly the same number of degrees from full up to full down position - the right one perhaps a few degrees more. The main problem is that the two servos do not travel in an identically linear fashion. The right wing flap servo deflects much farther with less input (either on the VR(D) slider or the SWC 3-position switch on the 10C Tx), as if there was a lot of expo programmed into the servo. I have swapped out the servos to see if that is the problem, with the same symptoms. Running the servo test utility on the Tx shows the channel 5 signal to be a good deal weaker than channel 6... but that may be irrelevant, since the servos exhibit the same behavior relative to one another when I swap channels.
The airplane uses split elevators, so I'm using channels 2 and 8 for them. I planned on using channels 1 and 7 for the ailerons. I believe channel 9 & 10 are not proportional, so of no help. Dunno about channels 11 and 12.
I'd sure appreciate some input, because this sure has me baffled...
Thanks!
PJ Wright, Chattanooga

Bax

My Feedback: (11)

It's not unusual for different servos to have slightly-different throws, even if they're the same make and model of servo. That's just due to the variance in components.

If you're using a pmix to slave the second flap channel to the first, then you adjust the mixing percentage of the slave to adjust the endpoints.

The 10C transmitter has 8 proportional channels and 2 digital (one end--other end) channels.