9:21 AM, Monday July 27th 2020
You're welcome! I'm no expert on the arcing thing, but maybe this metaphor helps: imagine you're driving in a car and while driving you notice the car is sometimes drifting off to the left a bit. You compensate for this by turning the wheel a bit in the opposite direction, telling the car to go a bit more to the right. The drifting to the left with your turning to the right results in the car driving straight again. It's the same principle with arcing lines. One needs to adjust the movement of the arm a bit in the opposite direction.
Again, I'm no expert on this, if anyone knows better, feel free to correct this. Otherwise I'm hoping this is helpful.