I did a search for the motor and found this: Good Quality! Wantai Nema 17 stepper motor 42BYGHM809 0.9degree 56oz-in 1.7A . Note the 1.7A. That could be 1.7 amps per winding . 0.4 amp supply might not cut it.
I did a search for the motor and found this: Good Quality! Wantai Nema 17 stepper motor 42BYGHM809 0.9degree 56oz-in 1.7A . Note the 1.7A. That could be 1.7 amps per winding . 0.4 amp supply might not cut it.