Dear Fernando, You haven't told us what you want to use the theodolite for.
There is a simpler instrument that can be used to determine vertical and horizontal angles called a "transit". They are often used on farms for laying out fence lines and drainage etc. They do not have the precision of a theodolite, but should be accurate enough for sundials. They are available new from various tool supply houses. I have an old Sears catalog that lists one for about $400 new. I used an old Sears transit to build my "Laser Trigon". I removed the optical components and replaced them with a laser. The device will project a sundial on any surface that sits still. It can be seen at http://www.shadow.net/~bobt/trigon/trigon.htm I hope this helps. Bob Terwilliger
