how to smooth stl model, smooth curves out of straight lines

I am a cnc novice trying to learn how to 3d carve using a 3 axis cnc router. The CAD output is an stl file. When I zoom in with an stl viewer, the flat faces that make up the complex 3d shapes are visible.
It may be that the machining resolution will naturally smooth the curves but I would like to know how to do it digitally in case the flat faces are still visible after machining.

Is there a simple function somewhere in my work flow from CAD to CAM to machine that I can perform a 'smooth' function that will either subdivide the stl faces so that they become irrelevant or create smooth curves out of straight lines.

For CAD I am using Blender
For CAM I am using deskproto
My router is an exel 6090 controlled by dsp pendant

I am a complete cnc novice so any explanation will need to be very simple.

Any advice much appreciated. Thanks.

You could try increasing your stl resolution when you export from blender. Or switch to a cam program like Rhinocam which may be able to import your model as surfaces rather than an stl.

You should be able to just increase the resolution until it is smooth enough to not be seen by the eye. This might cause issue with your computer and software as it makes the .stl file larger in size. You should hopefully be able to find a happy medium if you play about with the settings.

Thanks for that. I don't suppose you know where to find the resolution options in Blender do you? They are not apparent to me when I export as an stl.

I don't know if this is anygood I dont use blender but someone once sent me a link Using Blender for CNC milling with the Blender Bas-relief add-on | BlenderNation

Blender is more for animations, see if there's something more suitable here;
http://www.eland.org.uk/pages/Misc/cadnotes.html