Grnch is a command line tool and Go library for generating and working with G-Code for pen plotters using the grbl firmware.

The command line tool can post-process G-Code exported from Inkscape (using the gcodetools extension) to make it ready for plotting. It also features an advanced G-Code simulator to estimate plotting time, that simulates grbl’s line planner and takes acceleration into account, which makes it more accurate than other time estimators.

The Go library has an extensive set of primitives (lines, polygons, circles, ellipses, bezier curves) and operations (transformations, clipping, filling) to programmatically generate G-Code.

Grnch is not publicly available yet. If you are interested, please contact me per email or on Twitter.