Using Bad G Code on Purpose

I'm sure most of us have come back to find a failed print and a big pile of plastic spaghetti on at least one occasion. Usually that's the type of error we try and avoid, however sometimes there's a certain abstract artistic quality that would look really cool if it could be controlled just enough to form a desired shape, in effect creating a digitally made birds nest. I remember coming across a site with a G code generator that would allow anyone to design a simple shape, and then run it through this G code generator that would create toolpaths for this. There were various modifiers that would have the extruder oscillate along the toolpath to create different effects, however I can't seem to find the link anymore. Does anyone remember a project like this and have a link to the site?

If not would there be a way to trick regular slicing software like Simplify3D or Slic3r into creating this effect?

You can post-process G-code.

So you could slice something with Slic3r, then add (e.g.) 10mm to all Z coordinates after the first couple of layers. Or randomly/cyclically add/subtract a mm or so to all the X and/or Y coordinates.

I saw some prints of jellyfish that were done by letting the extruder extrude into space. You could either mess with the gcode to delete support material or post process using a 3D printing pen.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

That's a good point about just manually editing the G Code. I'll give it a shot and see how it works out.

The other trickier thing this program did was to make various oscillations along a given tool path to create various textures and patterns. I imagine it would start out making the path for a single walled shape and then apply a modifier to add offsets and overlaps in the tool paths. Is there a relatively easy way to edit G code to achieve this?

When I said post-process, I didn't mean manually.

In Slic3r & Cura (don't know about S3D) you can set up a program to automatically post-process the output. (e.g. this thread).

The oscillations to the tool path would be programmed as periodic additions/subtractions from the X & Y coordinates.