Apologies from atommann (an engineer from JLCPCB), about Gerber X2 files at JLCPCB

Manufacturing
34

I found that Gerbv can convert Gerber X2 to RS-274X file easily: Just open the file, Ctrl+s to save the active layer, then the file will be converted.

The contents of RoundRect macro from KiCad 5.99:

G04 Aperture macros list*
%AMRoundRect*
0 Rectangle with rounded corners*
0 $1 Rounding radius*
0 $2 $3 $4 $5 $6 $7 $8 $9 X,Y pos of 4 corners*
0 Add a 4 corners polygon primitive as box body*
4,1,4,$2,$3,$4,$5,$6,$7,$8,$9,$2,$3,0*
0 Add four circle primitives for the rounded corners*
1,1,$1+$1,$2,$3,0*
1,1,$1+$1,$4,$5,0*
1,1,$1+$1,$6,$7,0*
1,1,$1+$1,$8,$9,0*
0 Add four rect primitives between the rounded corners*
20,1,$1+$1,$2,$3,$4,$5,0*
20,1,$1+$1,$4,$5,$6,$7,0*
20,1,$1+$1,$6,$7,$8,$9,0*
20,1,$1+$1,$8,$9,$2,$3,0*%
G04 Aperture macros list end*

And this is the converted Aperture Macro by Gerbv:

%AMMACRO12*
4,1,4,0.013223,0.001044,0.001044,0.013223,-0.013223,-0.001044,-0.001044,-0.013223,0.013223,0.001044,0.000000*
1,1,0.017224,0.013223,0.001044*
1,1,0.017224,0.001044,0.013223*
1,1,0.017224,-0.013223,-0.001044*
1,1,0.017224,-0.001044,-0.013223*
20,1,0.017224,0.013223,0.001044,0.001044,0.013223,0.000000*
20,1,0.017224,0.001044,0.013223,-0.013223,-0.001044,0.000000*
20,1,0.017224,-0.013223,-0.001044,-0.001044,-0.013223,0.000000*
20,1,0.017224,-0.001044,-0.013223,0.013223,0.001044,0.000000*
%

What’s the difference? Looks like only the parameters are replaced with the real numbers.

I noticed circles (aperture macro primitive code 1) in RoundRect has 5 parameters (the 5th is rotation) but in MACRO12 it has 4 parameters. In Gerber Aperture Macros are hard for everyone, Lukas mentioned the extra rotation parameter for circles crashed CAM350 at Seeedstudio.

I’m also curious:

  1. Why traces are lost for some Gerber X2 files but most of them are OK?
  2. Why only two rounded corner are missing and other twos are kept for the rounded rectangle pads?

Regarding the 2nd question, I want to test CAM-B without the 5th parameter for circles.

EDIT on 2021-01-11

I tested how the 5th parameter will affect CAM-B, the result can be found here: