//Calculate start speeds based on moving axes max start speed constraints.
    int slowest_start_axis = primary_axis;
    unsigned long slowest_start_axis_max_interval = max_interval;
    for(int i = 0; i < NUM_AXIS; i++)
      if (axis_steps_remaining[i] >0 && i != primary_axis && axis_max_interval[i] * axis_steps_remaining[i]
              / axis_steps_remaining[slowest_start_axis] > slowest_start_axis_max_interval) {
        slowest_start_axis = i;
        slowest_start_axis_max_interval = axis_max_interval[i];
      }
    for(int i = 0; i < NUM_AXIS; i++)
      if(axis_steps_remaining[i] >0) {
        new_axis_max_intervals[i] = slowest_start_axis_max_interval * axis_steps_remaining[i] / axis_steps_remaining[slowest_start_axis];
        if(i == primary_axis) {
          max_interval = new_axis_max_intervals[i];
          min_speed_steps_per_second = 100000000 / max_interval;
        }
      }