The Gerber Output

The Gerber output generated by STL2GBR is very simple and suitable for almost any laser photoplotter that supports RS274X and the area fill command (G36/G37). There are no draws and flashes* since the original data is all polygons. Only polygon outlines are used and the Gerber G36/G37 area fill command is depended on to generate the fill.

There are no arcs (since the STL data has no arcs in it) and the smoothness and resolution is not controlled by the converter but by how smooth the STL data is -- most 3D tools allow the user to control in some manner the number of triangles used to approximate the 3D surface.

For example, in the slice shown above the data generated by STL2GBR looks as follows: (comments are in italics and not part of the file )

example1_3.gbr

%IPPOS*%                    image polarity positive
%FSLAX33Y33*%               format statement - format 3.3,
                            leading zeros suppressed, 
                            absolute coordinates
%MOMM*%                     units are MM
%LNintermediate*%           Layer Name: intermediate
%LPD*%                      Layer Polarity: dark
G36*                        Start of Area Fill
X2661Y4161D02*              move with Pen Up
X5000Y4161D01*              draw (each draw an edge)
X5000Y4500D01*              draw
X4896Y4514D01*              draw
X4871Y4517D01*              draw
X4774Y4557D01*              draw
X4750Y4567D01*              draw
.
.
.
X5000Y4161D01*              draw
X7339Y4161D01*              draw
X7339Y5839D01*              draw
X2661Y5839D01*              draw
X2661Y4161D01*              draw
G37*                       end of area fill
M02*                       end of file

[ * there can be flashes generated in the Gerber output when the polygon dembedding mode is used and the program identifies "round" polygons. This is a new function added to STL2GBR in order to help PCB designers create drill files. ]