Lost steps

After a long slow process I now have CNC mostly setup on my Shoptask
machine. The setup includes EMC running on Linux Redhat 5.2,
Camtronics 5A chopper driver in half step mode, and 150 in-oz motors.

In repeated attempts to determine the backlash on the axis, I find no
consistency in dial indicater readings. On the X axis I lose
.002-.003" cumalatively in one direction. On the Y axis the readings
are erratic with variations in the.002" area.

Before beginning I partially disassembled the carriges and cleaned
and
lubricated the ways, and adjusted the gibs. All seems to work
smoothly.

I understand these motors are not power-houses, but they should
certainly operate the machine with no load on it.

I'm using moves of a half inch each direction at 6 ipm for the tests.

The motors came with the machine when I bought it used and were
powered by a box, one axis at a time, with "The Motion Group, Inc."
on
it.

The Camtronics driver tests well and puts out the correct voltages.

Any ideas, and how should I go about finding the problem????

I'm a total newbie-dummy.