Update

Got the 48v power supply.

The driver was set at 20steps and I ended up leaving it there. At 8 steps it would stall when starting at full speed. However ut will now work at full speed which it did not with the 24v power supply.

To be honest I think I am at the end of the motors ability to raise and lower the Z axis and having seen a few more CNC conversion vids people seem to prefer the the Nema 34.

The Nema 34 may be overkill, but as they say in racing "Better toi have too much power than too little "

So Craig, if I was going to go the Nema 34 route what setup would you advise please

PS the Nema 23 would not be wasted as I would like to add power feed to the Y axis, which is a lot easier to move compared to the Z axis