I'm not really sure on that. Im not using the throttle from the joystick, actually I broke the slide pot that was the throttle trying to get it out of the housing

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I am using the two pots that were the X and Y axis of the stick as throttles. This works perfectly for me as I usually fly twin prop aircraft. Not really into the big stuff (unless it has a UPS paint job). As I usually have no need for reverse thrust I have never thought abot it before. Check out some of the other posts here in the homebrew section and im sure someone could answer this.