New Mill losing steps

[EddyCurrent]

thank you for the reply what is the best way to find the steps per revolution. I guess moving the machine in hand wheel is a start.

No, not how many steps per revolution but how many millimeters does the table move for one revolution of the stepper motor, you need this for both X and Y directions.
Looking at the photo, your stepper motors appear to be directly coupled to the end of the lead screws and therefore have a 1:1 ratio.

In Mach 3 the calculation for 'steps per' is;

((360 degrees / motor step angle) * microstep value) / screw pitch

So for your machine we don't know the screw pitch and that is what you need to do by turning the screw one rev and measuring the table distance moved.

As an example for my machine the calculation is;
((360/1.8) * 8) / 10 = 160 steps per.

Similar to what jazzcnc said but using 1/8 microstep it looks like your machine has a screw pitch of 2.0176mm which sounds a bit odd.