Larry-
I was able to work on the drive for a few minutes today. I swapped the X and A axis. The servo motor was still acting the same.
I swapped everything back, and then removed the cover to the US Digital E-5 encoder. The disk was covered in a whitish grey powder. I took the encoder apart, and wiped the disk with alcohol. It helped, but it is still skipping. I think I have a new encoder I am going to install sometime this weekend.
I am going to look for a sealed encoder, do you have any recommendations on maker or model #
thanks
Steve