Looking for a slew drive less than 7" in diameter?

Desperately looking for a slew drive less that's than 7" in diameter?  Preferably with a nema stepper mount.  Don't want a rotary stage or table, looking specifically for a slew drive. 

http://www.bombayharbor.com/productImage/0892236001250832763/Solar_Tracker_Slew_Drive.jpg

thanks.



What's wrong with that one ?