Exports for 3D Printing

[gungazoid]

I've been able to create objects for printing by building them in W3D and exporting them to the .stl format. The problem is that if the item was created from more than a single simple object (two cylinders, say) the printer leaves gaps where the two constituent objects intersect.

Is there a way of changing a complex W3D object, built from multiple basic objects into a single surface? "combine" does not do it. That function has to retain the information on the constituent objects for the "separate" function to work, and the problem persists.

   

I need a command that will convert an object into a single surface. I realize that would probably be irreversible, but it would solve my printer problems.