I have a rotary axis controlled via a 320 gecko DC drive. I can tune it to give within a half degree accuracy on 3600 degrees rotation ( Ten rotations ). I can repeat this several times in one direction. When I command it to travel the other direction it is off by about 40 degrees ? There is less than 1/4 degree backlash in the gearing. Any ideas on where the problem would be ?

Thanks,
Scott