How to control parts by use variables in Vizzy?

NameOfPartThatRunsTheVizzy.FlightProgram.VariableName, Charodey explained it here. This way the input is controlled by the variable. So, for example, if the command pod/disk/chip is called CMD and your variable is called inputVar, you have to use CMD.FlightProgram.inputVar as custom input.

This craft uses variables directly as input for the pistons I think, but I‘m not sure how it works. I couldn‘t get it to work on my crafts yet.

Sorry if I didn't explain it well, try checking out the helicopter stock craft, and look at the input for the blades. That may help.

Without the funk expressions, you can use activation groups (or activate part blocks), to turn a motor on/off, but you would have to use a slider for rpm or torque input, depending on whether the throttle of the motor is governed. I don't think you can use Vizzy variables to control a motor without sliders. Edit: You can enable "advanced properties", and set the input of a motor (or other part) to things like FD.acceleration for example. I think I've seen someone do an expression in the input controller, so if you use the proper syntax, then yes it should be possible.