Size of gerber files exorbitant!

Software
1

Hi at all!
With Version 5.0.1 of KiCad I get gerber files, which have almost the triple size of the gerber files generated by any version of KiCad 4. Is that normal? For example, I have version 4.0.7 of KiCad which generates a gerber file (e.g. Top layer) with a size of 30MB. With 5.0.1 the size of the gerber file of the SAME project is almost 90MB. I can’t believe that’s normal.

2

You might want to report this as well as your other report over at the bugtracker. (I can not find any mention of it on the bugtracker at this point.)

3

Are you using rounded rectangles or custom pads? These will use far more Gerber description than circle or rectangle pad primitives

4

Hi!
Now I know what the problem was. I always used the “segment” option instead of “polygon” when created a polygon. Every polygon I created in low resolution. I changed it from “segment” to “polygon” and the size of the Gerber file is now only a little bit more than 1 % of the size before. In that case I wonder, what’s the difference between polygon and segment, or what the advantage of the option “segment”. In my case it wasted a lot of memory, but I couldn’t see any advantage.

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5

(Somebody who is fluent in “Gerber” is welcome to correct me . . . . )
The “Segment” fill method creates a fill zone (“copper pour”) as a series of overlapping line segments, each one the width of your specified “Minimum width” for that particular zone. It may take a zillion such segments to completely fill a large zone. The “Polygon” fill method describes the zone’s filled area as a polygon, using the location of each consecutive vertex. Even a very elaborate polygon may have only a few hundred vertices. The syntax of the Gerber file specification knows that the polygon should be completely filled with copper.

Dale

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6

I presume that polygon is a late addition to the Gerber format, as it was originally just a set of optical projection and shutter control primitives.

7

See https://www.ucamco.com/files/downloads/file/81/the_gerber_file_format_specification.pdf?e0286002fc100c1233dcb855d6aaa64b
page 170, “Painted regions”.

1 Like
8

Which says that painted or stroked regions are deprecated

9

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