Wire suspension seems to be a great solution to reduce part count, and gain speed.
 

And another take on wire suspended mechanics:

Wire suspended radio telescope system:

Research Publications: (For full text of papers go to publication homepage)

Some Movies:
·	LAR movie long (19M)
·	LAR movie short (5M)
·	Feed movie short (6M)

http://saba.kntu.ac.ir/eecd/aras/projects/CDRPM.htm