Hi there,
I have purchased a Futaba 10c set and have set up my glider on it using Glid 1ail+1flp. I have defined a mixer to apply elevator when deploying air brakes which are on ch3 with ch2 being the slave. The mixer is on all the time.

What I want to do is adjust the rate in flight to trim the model out, can this adjustment (rate) be allocated to a VR knob so it can be turned in flight ???

Thanks<br type="_moz" />

Basically, you want a way to change the percentage of mix "on the fly". Unfortunately, the 10C doesn't have that provision in the mixers. What you want to do is use a point mix and then define the points of mix you need...it will take several flights and a bit of "try and see" to get the mix ratios correct.