Bézier Bowl

One more vase-type-thing: a customizable “Bézier bowl”. It produces models by rotating a cross section around an axis, just like my chalice lathe. The difference is that instead of drawing the cross section directly, you draw control points to define the path of a smooth Bézier curve.

Bézier curve tools are found in many drawing programs. Normally they feature a live preview of the line with interactive handles for the control points. Since the Thingiverse drawing widget wasn’t exactly designed for this sort of [mis]use, a bit of imagination is required to visualize how the customizer works. I annotated this screenshot with labels and the correct Bézier curve overlayed with Inkscape. It’s linked to a video clip showing the customizer in action:

I printed the bowl shown in that example. It was the first thing I’ve printed with ColorFabb woodfill, a filament composed of conventional PLA infused with wood fiber. (I got mine in a sample pack from Printed Solid.) Here are the results:

I had some trouble getting started with the woodfill because it is much runnier than regular PLA. As a result, it really oozes out of the extruder when idle, and seems prone to jamming/clotting if not extruded continuously. However, after increasing retraction (to compensate for ooze during travel moves) and boosting print speed (to keep up with the flow), it prints quite reliably.

The finish is pretty remarkable, too; definitely woodlike, but of course with an artificially uniform fine grain. Thin-walled woodfill objects almost feel a little unearthly – like wood to the touch, but translucent and feather-light.

Posted on Wednesday, March 26th, 2014.