I had bought 4.6v 2 a/phase stepper motor .
can I connect it to drv8825 ?
You should be able to drive that stepper motor with the DRV8825 carrier. However, you will only be able to get about 75% of the motor’s maximum holding torque since the DRV8825 carrier can handle around 1.5A per phase without adding some additional cooling (e.g. forced airflow or heat sinks).
So can I get full torque if I use forced airflow?
please help me with these . I am thinking of a water-cooling system for drv8825.
then can I use it with my stepper motor?
Getting 2+ amps per coil from this driver is going to require substantial cooling (likely involving forced air flow and a large heat sink), and I am not sure how practical it will be for you to achieve this level of performance from the DRV8825.
We do not have any specific recommendations for a heat sink or fan, and view adding a heat sink as an advanced modification, but we generally expect forced air flow to be the most effective method of cooling.
If you try a water cooled system for your driver, I am sure many people would love to see it. A good place to share would be the “Share your projects” section of the forum.