Liquid metal drop-on-demand (DOD) additive manufacturing enables precise control of individual droplet deposition. A critical bottleneck in this manufacturing process is achieving continuous, uniform droplet ejection, which is influenced by several parameters, including nozzle diameter and pressure-pulse actuation mechanism. To address this challenge, this study investigated droplet formation using the Volume of Fluid (VOF) method, as it conserves liquid volume, incorporates free surface tracking and interface evolution during droplet formation. The effects of nozzle diameter and duty cycle on droplet size, detachment time, detachment distance, ligament stability and satellite formation were investigated. The results revealed that the droplet diameter scales linearly with nozzle diameter. The gas pressure required for single droplet ejection decreased with increasing nozzle diameter, while the resulting droplet velocity also decreased. The DOE revealed different flow regimes. Droplets with diameters between 0.55 mm and 0.95 mm were produced at 100 Hz, as the duty cycle was varied from 10% to 50% for a 0.3 mm diameter nozzle. Higher duty cycles resulted in larger droplet diameters, droplet overlap and formation of satellite droplets, which led to unstable ejections. Parameter sets were identified for efficient droplet generation, which provide preliminary insights into nozzle diameter and pressure-pulse design for DOD metal additive manufacturing.