1.4 with TB 6560 boards

I am fairly new to all of this so please forgive me. I'm in the process of trying to convert our ZTW CNC over to a 3D printer. The ZTW used TB 6560 boards to drive the motors and I figure it would be best to continue to use them since I know they work.

First question: Any issues with this combo I should be aware of?

Second question: The TB 6560's are wired directly in to the power source from when it was a CNC. Should I leave that as is? I'm looking at the 1.4 wiring diagram and of course it's using drivers directly attached to the board and power is being fed right to the board. I'm looking for guidance on how to wiring this all up really. Leave power on the TB 6560's, also run power to the board, hook up the 4 wires off of each TB 6560 to the 1.4?

Power supply is 12v 5A
Steppers are NEMA 23's
I do have DRV8825's as a backup.

I did the same before, it works but the speed is very slow. The fast I can set is 40mm per second.
About the connection, it can direct wire from 1.4 to tb6560 board, motor pin to motor pin. BtW, 6560 have pulse limitation, firmware marlin not drive it well. I changed to use tb6600.

Thanks for the heads up. I'm going to try first with some DRV8825's as the setup is simple. If it doesn't work I'll fall back to the 6560's

My 2 cents again, the power supply 12V5A is far from enough current for 3D printer, Normally, "4 X NEMA17 + 1 Hotend + heated bed" almost need 12V20A".
The NEMA23 rated 3A each and NEMA17 only 1.5A.

The TB6560's will work fine. They need a longer step pulse than most drivers which is why Marlin firmware doesn't drive them well. Marlin uses a very short step pulse. Teacup firmware already has a fairly long step pulse length and Repetier firmware has a setting to lengthen the pulse so either one will likely get those drivers running fine. There are people who have modified Marlin to work with TB6560 drivers so it's not impossible, it's just a bit more involved. Not sure what you mean by 1.4. Is that ramps, sanguinololu, something else?