Been working on this project for a couple weeks.  Hope to have something that moves by the end of the month.  See the different version iterations in the gallery.  Original idea was going to be a one piece design.  That evolved into 2 part, a block and a bearing.  Then the bearing wasnt working out great so I got off the shelf bearings.  Check points are: 

1.  Get 1 axis moving (camera slider)
2.  Get 2 axis moving (XY Plotter/laser)
3.  Get 3 axis moving!