zoomkat:
It would be easiest to have a standard "park" position for the servos before shutdown, then initially attach the servos in this position on startup.
That's a nice idea for many machines, but it's a model excavator. So 1) to account for -unintended- shutdown/reset, and 2) real life modeling, the best would be
void do_nothing_don't_move();
In a real life excavator, on starting the motor, swinging the arm in/out and opening/closing a clamshell are not very safe things to do. The system waits for the operator to tell it what to do.
After finishing a job, having a dedicated 'home' button, and then shutting down, would be a nice feature.