Step generator and simulator for a simple V plotter. The math is explained at

For an online demo of the simulator, visit



node gensteps.js gcodefile

It will write the result to the standard output which can be used by the simulator, or by a real V plotter.

For a real V-plotter, you also want to configure the generator by editing gensteps.js, e.g. the resolution of the stepper motors and other stuff visualized by configuration.png.


It is mainly designed to work with the gcode generated by juicy-gcode. It should work with every kind of gcode, but it is not well tested. The plotter draws when the Z coordinate is 0.


Please file an issue if you run into a problem (or drop me an email to