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Material choices

	METHOD	MATERIAL	COST ($/sf)	TIME: file prep	TIME: fab	TIME: assembly	TIME: total	MATERIAL RECYCLABILITY
	CNC milling - smooth terrain	white foam	$8	7	2	0.25	9.25	no
	CNC milling - smooth terrain	plywood	$40	9.5	Expand title 6.75 2.25 h to mill the base, 4.5 h to cut the buildings	1	17.25	yes
	CNC milling - smooth terrain	hardwood (poplar)	$34	9.5	Expand title 6.75 2.25 h to mill the base, 4.5 h to cut the buildings	1	17.25	yes
	CNC milling - smooth terrain	high density foam	$83	7	2	0.25	9.25	no
	CNC milling - stepped terrain (fine)	white foam	$8	14	3.6	0.25	17.85	no
	CNC milling - stepped terrain (1/16" contours)	white foam	$8	7	2	0.25	9.25	no

File preparation: Rhino

1. Generally, the rhino file prepared for milling must contain the following layers:
   1. Stock: a box, at the world origin, representing the size of the block of your milling material.
   2. Topography: a single NURBS surface for smooth terrain, or a series of flat surfaces for stepped terrain.
   3. Features: layer(s) with NURBS surfaces for roads, water, etc.
      1. For each features layer, there should be another layer with boundary curves for each feature surface.
   4. Buildings: If buildings are to be milled with the base, include a layer with NURBS surfaces at the tops of buildings.
      1. A layer with boundary curves for each building top surface.
   5. Buildings too large or too small to be milled with the topography need pockets. Include a layer with curves outlining the bases of these buildings (at the z depth you want the bottom of the pocket cut).
   6. Final contour: a layer with a curve tracing the four outside edges of the topography layer, and the same curve projected to z=0.
2. This file can be imported directly into Mastercam.

File preparation: Mastercam

1. See the CNC tutorial for more detail. In general, you will need to use a template MasterCAM file, import your geometry, assign it to pre-defined toolpaths and adjust the toolpath parameters for your material.
2. Files must be submitted to CNC TAs for review and approval.

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