Thanks Lee for the moving of the post and thanks to Neale, irving and Jazzcnc for information.
Yes I realise that I am still on a learning curve but with the response received I am willing.
Up to now it was a tremendous experience, making all the components for a cnc engraver.
Not only the making of components but a human interface that it created. Free advise, free scrap aluminium and free assistance.

The volt/ohms value of the steppers are so low so I thought that keeping the supply low will assist in limiting the wattage. I presume the stepper values are kept low to keep inductance low.
What seems to come out of the discussion is that higher voltage, ordinary transformer power supply and current limiting will be the answer. (thanks Neale for the SMPS tip)
My power supply is not built yet so any voltage is possible. I am going to start off with an existing, 20Volt/5Amp, CC-CV, bench power supply.
My home made driver PCB does not have built-in current limiting, hmmm, I should incorporate it in the next version. I do have fly-back diodes on the motor leads for the back emf. BTW I am using PCB SPRINT Layout software, available from Abacus in Germany.
Again thanks for all the replies, much appreciated.
I will post the progress.