In some examples, a printing device includes a first print drum comprising a first ring gear defined on a surface of the first print drum, a second print drum comprising a second ring gear defined on a surface of the second print drum, a rotatable drive shaft, and pinion gears to engage the first ring gear and the second ring gear, wherein rotation of the drive shaft causes the pinion gears to interact with the first and second ring gears to rotate the first print drum and the second print drum at different angular velocities.