Rhino file tolerance can be set from the document properties window in the units tab. A good rule of thumb is to set your Rhino tolerance to be 10 times that of the printer tolerance (i.e printer tolerance is 0.1mm, so Rhino tolerance should be set to 0.01mm).
You first need to set correct tolerances before you start modeling by finding the tolerance of the program you are exporting your model to.
