DAVE,
What was the minor damage?
As others have replied, you just move in one direction, set the DRO's to zero, then move in the opposite direction and see the difference between commanded move to measured move. It's assumed you have the steps per unit correct. There are a few things to be aware of:
1.Make sure that the screw is parallel to the axis, gibs are properly adjusted,the nut and it's associated assembly have no movement, and that the screw bearings or collars are preloaded if that is possible.
2.There is no such thing as zero backlash but can be minimized to a small amount. ie; bearing preload......the bearings or collars can affect backlash
and depending on how preloaded can account for differences in backlash.
3.Don't know what kind of screw you are using, so the backlash can be different depending on where you are measuring along the screw length.
The backlash can end up being different from one direction to another, depends on the screw, nut, and collar / bearing preload.
So you check and adjust the above as best you can for what you have.
The indicator should be perpendicular to the surface and suggest using a tip which has a flat face on the end. A fine point can easily land on a surface mark and give you a false reading. Don't use the end or beginning of the indicator travel but rather after is has indicated some. Suggest you move
the axis , say 0.1" and not jog / move in 0.001" steps. Then move in .1" steps a few after the backlash was taken out and the movements should be the same.
Need to be meticulous when checking. There is more that affects the backlash , a few settings on how it's implemented etc, but for now this should
get you in the ballpark.
RICH