Power requirements for opposing stepper motor rotation

Hi all,

a project I'm working on has me wanting to control two motors connected to each other with bungee cables, that rotate in opposition (i.e., one rotates CW and the other CCW). I'm using two NEMA 17 stepper motors and an easy driver for each. I've wired up the motors the as shown in the multiple motor example on the easy driver site. I'm using a 12v 8amp power supply, which I was under the impression would be enough power; however, the motors choke as seen in this video. The desired effect would be for the cables to begin to ravel and then unravel. Do I need a stronger power supply? Are the motors not powerful enough? Is there something else I can do? I'm not sure how to troubleshoot.

Thanks in advance!

Motors clearly don't have enough torque. Note that steppers have more torque if driven slower, and using
microstepping is likely to help too. So try both slowing down and using say x8 or x16 microstepping to
reduce risk of resonance issues.

Have you measured the load torque? Guessing and torque don't go together well in my experience,
people don't intuitively understand it very well.

What are you trying to achieve, apart from torturing your motors ?