The assignment of this week concern the making of a composite.
To made it we must make a 3D model first and mill a mold with a CNC machine. For the subject I've chosen the mask "body" of my final project.
I took measures of a gas mask, and started the modellation of a 3D structure.

Files here: First and Second STL.

I made a lines structure to guide the program in the offset. However, in this case, it make better without line guides..
Than I do a the inferior structure of the mask. And I see a trouble to make it, because the mill cannot do some passages in this way.

To avoid this problem, I must do the same structure in the external base intead of the internal of the mask.

To cut the base I extruded the lateral lines and used the plane to cut the model. Than I used the boolean subtraction for the mask cave.
In this subtraction I had some troubles, resolved moving the piece 1 millimeter upper, for unknown reasons.

Another prboblem that I got was the deep of the mask. Because it was too high for the mill top. That forced me to cut the structure to made two passages.

The program used was Art Cam. The passages was:
Reliefs -> Import 3D model.
Toolpath 3D-> Machine

Roughing: 8mm Top.
Stepover -> 3.2mm
Stepdown -> 4mm
Feed rate -> 2.000
Plunge -> 300

Phinishing: 3mm Top.
Safe -> 5
Home: x,y,z to zero.

Before the cut remember to wear protection, turn on the air compressor and the vacuum.

As you can see I got problems on the phinishing, because I've setted a wrong size of the top on the program. So I had to restart all.

I made a new setting and coordinates. This time all worked well, however I must wait the next day before complete the piece.

I joint the two parts of the piece with the glue, and I used the polishing resin.

I covered the surface with an hardener, making attenction to not leave clumps.

Now we have to wait one hour at least to let it dry (perfect for a snack!).

I ordered the stratification of materials (as in the image), and covered the mold with an anti-sticking wax.

After that we can start covering the mold with layers of materials. On the rough one we have to put the resin, making attenction to cover all the surface, corners in particular.
Than cover with the rest of the layers (the wax became really hot on the process of solidifing).

At this point we have to wait again for less than an hour, and start with the "packaging" of the vacuum bagger.
After the air extraction we can close the valve and let it stay for swentyfour hours.

The next day we can see the result and start "triyng" to put it out.

The process was so difficult, so many that make impossible for me to pull it out without breaking the mold.

When the "hard" part ended I removed the part in excess, with some difficulties as well.
The final part was the polishing of the object with the glass-paper. And we can finally enjoy our work!