If I edit these blocks out, and the 'duplicate' blocks mentioned above, then the file is fine and the CNC router will cut exactly what I want - but it has taken me an hour or so to edit the file, so a bit annoying to have to do.

When I examine the Gcode file, these rectangles are actually indicated by a comment line (start cutting rect pathIDXXXX). ngc file, and it is followed by Gcode for a rectangle around the hexagon - the sides of the rectangle touch the hexagon. As well as this, every 'object' on the board is surrounded by a rectangle - that is, if the drawing shows a hexagon (for example), the Gcode for the hexagon is in the. Its not every block, and there appears to be no 'pattern' to which block is duplicated that I can see. However, this file appears to have some 'oddities': almost every Gcode 'block' is duplicated - if I run the file on the router, it carefully mills the shape I drew, then goes round it again. This all appears to work fine, and I end up with a Gcode (.ngc) file.

I then import this SVG file into Inkscape, and go through the usual procedure to generate a Gcode file - Object to Path, Tools Library, Orientation Points and Path to Gcode (all from the Gcode Extension). (when displayed with an image viewer - Pix in Linux) As far as I can determine, the resulting exported SVG files appear to only consist of these lines. Basically the layout is simply a number of copper 'lands' on the board, so the drawing is just a series of lines between the lands which will be milled out.

I need to produce some printed circuit boards by etching them with the router (long story), and started by producing a drawing of what I wanted in LibreOffice Draw, and exporting it as an SVG file. I'm using the Gcode extension in Inkscape to generate Gcode files for a small CNC router, and after making loads of mistakes learning my way around (and being helped by this forum - Inkscape is brilliant for what I need) I have another issue.

Svg to gcode inkscape