Test travel comes up short. I'm stumped

I'm have trouble getting the Z axis to move the specified distance. When instructed to move 1 inch it moves .77 of an inch. I have tried a bunch of difference setting in PncConf Wizard and just can get it to come out right. I even tried setting it up as if the Z screw was a .2 inch screw rather that the metric 5mm screw that the kit was supposed to come with. I don't think it an issue with losing steps because the measurement is the same moving the Z up or down and it is consistent. I have the head counter weighted.

I'm converting a Sieg X3 mill using the CNCFusion deluxe kit, Mesa 6i25 + &i76 Plug-N-Go kit with a Gecko 203v driver with 10 micro steps on the Z axis. The ball screw has 5mm pitch. I'm having no problem with the X or Y. They are using KL-5056 drivers set to 8 micro steps.

John

If you have a 5mm screw, a 200 step motor, 10x microstepping and 1 to 1 or direct drive. Your steps/inch should be 10160. Don't forget to check for things like a slipping coupling or pulley.

Duh! I forgot the Z has pulleys and they are not 1:1. Thank You for making the light come on.

What a stupid mistake.

John