I built one many years ago in the UK. Very simple, but extremely sturdy. I'll describe it:
40mm thick aluminium base plate. 20mm stainless axle running in block bearings, tilt plate 20mm thick, with radiused edge to suit 20mm axle which was bolted to it. At the back were a pair of stainless turnbuckles, with rod end bearings each end. One end bolted to fixed plate, one end to tilt plate. The base plate had blocks with azimuth adjust screws each side, and a fixed post on the pier/tripod to to act against. Put a sheet of 3mm thick Teflon below it to slide on.
If I can find a pic, I'll post it.
Someone did see it at one of the star parties and blatantly ripped it off (not that I mind - he's a friend!)
The link is here: should give you the general idea.
http://www.zyworld.com/Domehome/Obse...es/FULL/32.JPG
It's rock solid, and won't budge. The weak link will then be the scope forks and your tripod.
Regards,
Rob.