I just finished assembling my Motor Shield and needed a stepper motor to test it out with. I have several printer motors that I've salvaged over the years, one of which is an OKI QH4-4487 rated at 24.2 V, 8.8 ohms. This requires 24.2/8.8=2.75 amps, way more than the L293D can handle. I have an old wall wart Motorola Cell phone unregulated charger rated 4.5-9.5 VDC, 800 ma. It's open circuit voltage read 5.25 VDC which at 8.8 ohms will draw 570 ma max.
I ran adafruit stepper test at single, double, interlace and micostep commands while measuring the average voltage and current drawn at the boards external voltage connector.
Single, 4.16V, 280 ma,
Double, 3.37V, 385 ma,
Interlace, 3.75V, 340 ma,
Microstep, 4.45V, 220 ma.