Before revision:  We unexpectedly find that symmetric sawtooth potentials maximize time asymmetry, while earlier work examining ratchet models of molecular machines required asymmetric sawtooth potentials -- a distinction related to differences between autonomous and deterministic driving .
After revision:  We unexpectedly find that symmetric sawtooths maximize time asymmetry, while earlier work examining ratchet models of molecular machines required asymmetric sawtooth potentials -- a distinction related to differences between autonomous and deterministic driving .