All Drawing lines come in on the VISIBLE Layer, and you EITHER have to select the geometry and move it to a named layer, or you have to create new geometry on a named layer and constrain it to the default drawing geometry. I have a drawing template that already has a number of standard layers defined (a 4x8 sheet of material), but you can add the named layers to any drawing.
If it is a simple project, you can just select the geometry, right click, and then Set Layer the geometry to that named layer. You should be able to select multiple lines, arcs, etc. at one time and move quite a few geometries to the new layer (like a lot of shelf holes).
However, if you have a more complicated geometry where lines overlap, then you have to re-create the geometry (with the named layer selected) and constrain the geometry to the drawing geometry. This is the case where notches of dados have geometry that also correspond with the edge of the material. You can not move that single line to multiple layers, and you have to create a new line to overlay the original line. You can move the drawing line to the Outline layer, and then constrain the Dado line to the Outline line. For more complicated drawings, I just re-create all the cutting geometry and leave the original drawing intact so VISIBLE layer can be ignored in the MasterCAM Strategy definition. The saving grace with most of my complicated drawings, is that they can be re-used with another model, and a lot of time is saved. I constantly re-use my cabinet parts drawings by just copying them to the new project, and then pointing them to the new project when I open the drawing.
Most drawings I do seem to allow me to use a simple rectangle or circle to define the outline of the cut. A finger joint part is a real pain, but I am able to re-use that same drawing on another project. I often trace the outline of a complicated part a bit larger than the part, and then go around the part and constrain it to the underlying drawing geometry.
So for manufacturing 30 cabinets, I do one set of drawings, and that is where the "A" comes in with the ATP. For 5 years of doing cabinets, I mainly work from the one set of drawings, with modifications to special parts as required. Saves a whole lot of time. For these stupid finger joint boxes, I am able to make all different sizes of box from one set of drawings. The ATP is really great in nesting a lot of repeatable items such as cabinets (Kitchen, Storage, Display....). My Blind Dado construction cabinet drawings have a lot of dados, but again I only made them once (which was boring for a short time).
With my layering conventions setup, it is easy for me to do a "Single Part ATP", as well as nesting multiple parts using the ATP.
My "CNC" drawings do not contain any borders, and the only lines on the drawing are the parts. I do not show hidden or other phantom lines that are not needed to manufacture the part (hence all lines on VISIBLE layer). Most of my CNC material is 4x8 sheets, but smaller items like the finger joint boxes could be smaller. However, I created each individual part on a 4x8 sheet. Align one corner to the Lower Left edge, and that saves you time when using some programs that do not shift the origin of the parts like the ATP. Then I export the individual DXF file for each part.
In the case of "one off" parts (such as Plexiglas router bases), I have been using the FBM Mill function of MasterCAM. It will automatically recognize all the parts geometry and automatically create the toolpaths for you. It is not perfect, but it is a fantastically quick start from which to refine. Woodworking parts are well suited to the FBM Mill, as it only works with straight sided holes and pockets.
As for layer naming, unless you have a convention used by your CNC, I use the Thermwood layering convention. It consists of the milling operation such a OUTLINE Z#P###, where Z indicates the cut depth, the P the decimal point, and # the value for the depth. You can also add the bit diameter D#P###, but I save that for the Operation definition (where you can define different bit sizes based on the current job). I use this convention with ShopBot, AH-HA and MACH3 controllers and it keeps things a lot better organized than my initial attempts at naming the Operations myself.
