An excavator with thumb I presume......Y'all realize it's firewood, right? This isn't finish carpentry. As long as it fits in the stove and burns, it's fine.
I'm one of the idiots who use the bar to measure. My Stihl is 18 inches and I just mark the spot from the butt to the cutt by eye, then squeeze the trigger. Using the excavator to pick up the logs and cut into rounds is awesome, then I use the excavator again to pick up the rounds and toss into the shop for stacking.