IFC export and viewer

I am designing a ski house in utah, and we are working with a cnc shop out of salt lake to fabricate some parts. The shop is running CADworks, and they are planning on converting our Revit model to .IFC (?) to generate tool paths. I've not used this file format before, and I was wondering if anybody has had experience converting from revit?


here;s the machine they'll be using for the roof framing.
http://www.youtube.com/watch?v=dIdKlG7CmW4


update:

I tried exporting the model and opened it with Data Design System's free viewer. The problem i'm having, is that none of the wall assembly information is exporting. i set up a clipping plane, and sectioned the model, and when i take a close look at my walls, there is no visual way to determine the assembly. this is important for the milling we intend to do.

the export settings do not modify the model. Wheter i specify in the ifc options that:

Finish 1 [4] - NotExported
Finish 2 [5] - NotExported

or

Finish 1 [4] - IFCwall
Finish 2 [5] - IFCwall

the result is the same. can somebody explain this to me?

I'm pretty new to those settings myself, but isn't it Not Exported without the space? (not at my work machine just now)