I raised the question of dimensioning in 3D in my first post and since then have experimented to find out what the problem really was. It seems that when dimensioning objects in the Z axis ,(height of extruded objects), the extension lines, dimension lines and text get offset from their associated definition points by various distances that can cause the total model space to be quite large and consequently the screen view of the object can become quite small. I have lived with this by exploding the "offending" dimension(s) which seems to delete the definition points. I then move the exploded components of the dimension to the position I want them to be.
I am embarassed to mention that I am using autocad 2000 . I recently tried to download a 30 day trial of the latest autocad. The excercise nearly blew all my 7 GB of download allowance and all I have got is about 300MB of autocad 2011 sitting on my hard drive which I can not get to run. The download is via the Autodesk site and I am disappointed to say the least about a lack of information on what to expect or how to execute the downloaded software.
Paynie