Check this out:
http://members.cox.net/tfangrow/hissdrive.html

Otherwise, barn door mounts:
http://www.mikeoates.org/mas/projects/scotch/
http://www.astunit.com/tonkinsastro/atm/projects/scotch.htm
http://www.davetrott.com/DoubleArmBarnDoor.html

Equatorial platforms:
http://tech.groups.yahoo.com/group/eqplatforms/

Lots of other links:
http://members.ziggo.nl/jhm.vangastel/Astronomy/links.htm