**5. E**ff**ects of Arc Length on Droplet Transfer**

There are three types of projected transfer in pulse GMAW: "multiple drops per pulse" (MDPP), "one drop per pulse" (ODPP), and "one drop per multiple pulses" (ODMP). ODPP was recognized as the most ideal transfer mode, and was mainly affected by the pulse peak current (*I*p) and time (*t*p), but not base time (*t*b), by many researchers [13–15]. In addition, *t*<sup>b</sup> was believed to be a parameter for adjusting the arc length. However, in this work, when *I*<sup>p</sup> and *t*<sup>p</sup> were fixed, it was found that the arc length had crucial effects on droplet transfer as well as the droplet impact force by only changing *t*b.
