XY-table (unfinished)

My contest to design an XY-table
( http://www.bitsfrombytes.com/wiki/index.php?title=User:MarcusWolschon/Challenges and http://www.thingiverse.com/thing:1757)
may have been too complex a task, so I designed
the basic frame myself so you have a starting-point.

Required work:
* add a work-surface
* add a handle
* add an additional piece to hold the captive nut in the middle and screw it to the inner side of the frame above to make it move
* add holes to mount it to a table
* take away s