How to set up External TB6600 driver for Nema 17

Hello Community,

I want to bridge the pololu socket to SainSmart TB6600 (or similar) external drivers to be able to drive the Nema 17 at their rated 24-48V. It appears that not many people have tried my (stupid?) approach before.

Here is how I plan to bridge to the external driver (note there are specific pcbs for bridging):
[attachment 109577 ExternalDriverWiring.jpg]
[attachment 109579 s-l300.jpg]

I have 3 Nema 17 Motors here which I want to drive:
[de.nanotec.com]
[de.nanotec.com]
[de.nanotec.com]

They all have an "Current per Winding" but I do not know what this exactly means. How do I know at which current to run the Motors at 48V?

- Can I just take the 1.7 A from the current per Coil as stated on the legend?
- Or do I have to calculate it from the Torgue curve: 17W / 48 V = 0.35 A?
[attachment 109578 2019-01-2211_38_00-Window.png]

One of those 3 Models is Unipolar, which should allow me for higher speeds with my ballscrews. Do you know if there are unipolar Stepper drivers that I can hook up in the above way or how does that work? If its not possible, Ill just use them in Bipolar mode.
[attachment 109582 2019-01-2212_29_02-Window.png]

Best regards,

Julian