The STL file format is used a lot for 3D printing. This is a tutorial at Shapeways site with some tips:

https://www.shapeways.com/tutorials/viacad

You can also change a solid or surface to a mesh using the Edit -> Change Object Type and select mesh.
This pdf explains the MeshParameters dialog box settings. It is from Tim Olson's book "ViaCAD Tips and Tricks". You can find it here:

http://www.masterviacad.com/store/page21/index.html

Recommend this to everyone using TC.

Enjoy
Mitch