It looks like the climactic scene in a monster movie, Arduino vs. Bot. In reality, this setup enables me to keep the ATMega328 chip on the Arduino while I upload test programs to locate the servo centers.
According to the results, the left servo center has drifted from 90 to 99 degrees while the right center is at 65! Maybe during conversion from fixed to continuous, I should have hot glued the potentiometers instead of soldered.
BTW, here we see the tragic story of pin D9, a casualty of moving the ATMega back and forth between Arduino and Bot without enough care:
Despite the mangled leg, the rest of the microelectronic centipede is limping along just fine, so there’s no reason to replace it just yet. And so the battle goes on . . . .