Thanks Gerhard.
This is the spec of the drives I'm using.
X and Y axis use MSD752
• Supply voltage up to +75 VDC
• Output current up to 5.2A So that 390Watts
Z Axis use MSD542
• Supply voltage up to +50 VDC and 210 Watts
• Output current up to 4.2A
I have now fitted a 48V 7.2 Amp power supply which is 345Watts, It may just be enough..
George