My First Model ( cheap ; )

Check number of subdivisions before apply and export to STL. And don't use smooth shading if you make model for print or CNC, because smooth shading not shows real mesh.

Thank you Skapricorn :)

so subdivide a max ( without smooth shading ) is the solution , if i understand ..
( more details here --> http://blenderartists.org/forum/showthread.php?287247-how-to-save-a-mesh-set-as-quot-smooth-quot-as-a-smooth-stl-for-3d-printing-or-simpe-remesh )