one stepper motor as controller for another?

encoder > arduino > step controller > motor

I definitely understand that this is the standard way to drive a stepper motor.

Feedback is a pretty good way to describe what I am looking for. Or 2-way operation. Also really cheap and bulletproof.

At this point, I am mostly trying to figure out if the back EMF of the remote motor will push back as torque on the local motor.

I guess I should just grab two identical motors. Start with just one hooked up to a scope and see what comes out of it when being turned slowly and very slowly.

Then, using a pair, connect them in series with a DC power source and see if one can modulate the DC to drive the other.

It really seems like they would operate as a 1:1 chain drive between gears.

I have seen plenty of online experiments where a stepper was used as a rotary encoder, but never anything bi-directional.

I was mostly just wondering if anyone had any experience with trying these sorts of experiments.