Servo torque test question

Hi all,
After having very little luck finding someone in this group
that has applied Gecko g320/340 drives to a mill the size of
mine I have decided to try and size servo motors that will
work on my mill. The question I have first is, can torque
required to run an axis be determined relatively accurately
with a string around a drum attached to the lead screw and a
spring scale pulling on the string at a fixed speed. I hope
this isn't too dumb a question but I wanted to double check.

Thanks Bob