power supply design/selection for 3 axis cnc

[saifu14]

Please help me in modifying a power supply (by modifying a PC ATX power supply) for my 3 axis stepper motor controller for a hobby cnc machine.
My motor specification:
Bipolar hybrid
3.2V, 1.8degree
2.8A per phase,
1.13OHM per phase,
3.6mH inductance per phase.
Holding toque 189NcM.

I'm planning to build all electronics by my self.
Th controller chip is not decided and may start with TB6560AHQ or L297+2XL298 for each motor.

my first step is to modify the power supply and so far I made 19V at 4.5A available after modification (only tested that much fearing the overheat) and could push up further.
But I don't know how much voltage and amperage actually I needed?.
assume that motor power will be fully utilized.

[saifu14]

While refering to this link http://www.ams2000.com/pdf/step101.pdf I got some thing like this..

Typically a power supply capable of delivering 1⁄2 or more of the peak phase current should be sufficient. For example, if you are using a motor with a maximum phase current of 4A per phase and assuming the drive is set to this maximum value, a power supply capable of delivering 2A or more will be adequate in most applications.

So my requirement might be, (2.8A/2) *3= 4.2A. is this sufficient?
assuming chopper supply voltage is around 24-30V.