The expanded polystyrene I’ll be using as the mold is non-toxic, and it’s unlikely to gum up the end mill. Allegedly it’s used as testing material, so I’m not too worried about the speeds and feeds.
So far I read Shapeoko CNC A to Z by Julien Heyman, and I looked at my .nc files in an online viewer. All the toolpaths look to be in the vague vicinity of the part.
If you have any recommended reading, please let me know!
The foam cores are cut inside the router (Shapeoko). Afterwards they become the mold for the carbon fiber and resin (i.e. the matrix). The layup, the process of putting the matrix over the foam, is done by hand, so the endmill never cuts the matrix, only extruded Styrofoam.
I added the carbon matrix in SolidWorks, which helps show how the composite fits over the foam.
Hopefully the exploded views make it a bit more clear. However, you would never see the shell separate from the foam like this, once the resin dries the foam is glued to the shell like the sarcolemma around a muscle fiber. The shell forms one rigid piece. Same with the foam cores, the two halves inside each piece would be glued together, then surrounded by the matrix. The foam stays inside and contributes a little to the strength. This particular part has a fixed part and a moveable part connected with a hinge which is necessary so that the controls can work:
