Best idea is
to put in a crosshair eyepiece and align one crosshair in the RA
direction by turning off the drive and watching a star drift. Begin
with a star in the south. With the drive on, see if the star drifts
in dec. If it goes north, towards the pole, then the Platform is
pointed too far east. If the star goes south, then you are pointed
too far west. Ignore for the moment any drift you might see along
the RA axis. Move the Platform slightly east or west as needed to
zero out the drift.
Then look at
a star in the west and again align a crosshair with the RA movement.
With the drive on, if the star drifts towards the north, then the
Platform axis is pointed above the pole. If the star drifts south,
then the Platform is pointed below the pole. Compensate accordingly
by tilting the Platform as needed using the Platform's adjustment
screws. After you have pretty much zeroed out the drift both ways
(star in south, star in west), then zero out any drift you might
see in RA by changing the speed of the motor.
Here is a website
that also has instructions for drift alignment: