[chantepierre]

You must be right, there also must be mechanical steps or wobble at play here. I was hesitant because my 3D printer (lower-end than an Axidraw) seems capable of smoother angled/curved lines than what we can see here. On the other hand plotters I've seen (a long time ago) seemed to not eliminate all vibration in the pen.. but I did not see a mid to high end recent plotter running.

[alpaca128]

FDM 3D printers squish molten plastic onto the previous layer, and that probably helps balance out the limited "resolution" of stepper motors. Also I'm guessing the inertia makes the extruder movement a bit more continuous, after all it's enough to cause artifacts like ghosting when printing at higher speeds.