PA;PA;VS4.0;!VZ4.0;!PZ-4,40;!MC1;

Where the meaning of the different terms is this:

PA;PA;VS4.0;!VZ4.0;!PZ-4,40;!MC1;

PA; PA; absolute coordinates

VS4.0; milling speed = 4 mm/s

!VZ4.0; mill speed in the z axis

!PZ-4,40; movement range in z axis.

Dimensional conversion between mm and the Modela MDX 15-20 for which the Fab Modules files are generated is 40/mm. This is a cue given as well by Guillem. So the range of movement here is from -0.1 mm to 1 mm; -0.1 mm is the cutting depth; 1 mm is when the mill is moving over the board without cutting.

!MZ1; starts the motor.

Then come the orders or commands to beging the actual milling. The first line is like this:

PU1568,956;Z1568,956,-4;Z1566,952,-4;Z1569,953,-4;Z1568,956,-4;PU1568,956;

PU1568, 956; is Pen Up, to the coordinate 1568, 956;

This coordinates, where the machine will start milling, translated into mm [xx/40] would be: 39.22 mm, 23.90 mm. I understand these coordinates are referenced in some way to the 0,0 point that we are setting at the beginning of the process, with xmin and ymin. I still have to confirm this.

Then the next to sections between "terminators" [;] that separate each command begin with a Z, followed by three coordinates, such as:

Z1568,956,-4;Z1566,952,-4;

This successive Zxx,yy,zz; define the paths of the cutting mill. Compared to PUxx, yy; a third coordinate appears, that corresponds to the cutting depth, the z. Here this value is -4, in Roland coordinates, that translated into mm is -0.1, the depth of the cut. At the end of a trajectory there is a new PUxx,yy; order, that pulls up the mill, to go to the next one, until the job is completed.

!M0; stops the motor.

The file generated by Fab Modules have multiple !M0; I am not sure if all those are needed.

H; finally sends the mill home, to the original 0,0.

[rml file default 1/32"]

This is a file to cut the perimeter of the board all the way down, 1.7 mm. The milling-cutting is performed in four steps.

The header of this file is as follows:

PA;PA;VS4.0;!VZ4.0;!PZ-68,40;!M1;

The difference with the former is only in the !PZ command. It tells the machine that the range in the z axis goes from -68 [-1.7 mm] to 40 [1mm].

Then if we look at the PUxx,yy;Zxx,yy,zz; strings we see that the mill makes four succesive trajectories one of top of the other with steps in z as follows:

-20 [0.5 mm]
-40 [1.0 mm]
-60 [1.5 mm]
-68 [1.7 mm]

Eventually, the script finishes the same as the former one: PUxx,yy;!M0;H;

So there are no instrucions in the header on the z steps, but only the total range of movement in the z axis. These have to be looked for then on the side of Fab Modules and the parameters incorporated in the default profile for the 1/32".

We found that the difference that accounts for this in the default profiles is in the "3D Settings" menu.

Figure 01: Fab Modules screenshot with 3D settings pop-up menu

The parameters controlling the z axis steps can be seen in the 3D settings pop-up window:

Top height (mm): -0.5 mm [this corresponds to the first trajectory / level of cutting

Bottom height (mm): -1.7 mm [corresponds to the final, lowest level of cutting

Cut depth (mm): 0.5 mm [corresponds to the dimension of the steps; the final step, from -1.5 t -1.7 is the rest after performing two 0.5 steps at -1.0 and -1.5 mm.

Then the xy path option is selected.

The left parameters top intensity (0-1), and bottom intensity (0-1) ste both of them to 0.5 i don't know what they correspond to.

The 2D z (mm) parameter in the main "make path" menu is set at -0.1, the same as in the 1/64" deafault profile. It doesn't seem to play any role in this case.

A comparison between the parameters in the two default profiles can be seen in the two following tables:

3D settings menu

Main "make-path" menu