How to get more speed (rpm) in stepper motor 28byj-48 with arduino nano

ngermani99:
just want to gain speed.

Someone knows if it's possible?

Says here:

42 bots:
it offers decent torque for its size at speeds of about 15 rotations per minute (RPM). With some software “trickery” to accelerate gradually and a higher voltage power source (I tested them with 12 volts DC) I was able to get about 25+ RPM.

So if you're prepared to trust that blog, crank the voltitude up a bit.