Spiral Pot

Story

This spiral pot is living proof of an inescapable law of design: minimalism is hard. On its face, my goal was simple - make a pot held up by a spiral with an hourglass silhouette. 

I thought the idea would translate to an emotive pot. The coil, tightening in the middle and blossoming at the top, would be playful and exuberant.

 

Spirals have something of a universal quality, being present in everything from ancient petroglyphs to seashells to DNA.

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2-D and 3-D spirals abound

In spite of its universality, we seldom see it - perhaps our eyes are even starved for it - as the shape doesn't lend itself to traditional manufacturing techniques. (Indeed, so far as I can tell, the only widespread product with tapering spirals is found in the suspension systems of supercars.)

From a technical perspective, making a vertical spiral, aka helix, is trivial. It takes five seconds in CAD to make the helix, and another five seconds to sweep a circle along it. 

But when it comes time to creating a helix of variable radius, things start to get tricky. A precise description requires, at minimum, a quadratic parameterization of the form: 

x = r(t)cosθ(t), y = r(t)sinθ(t), z = kθ(t)

Lacking the courage to convert that into CAD, I sought an approximate solution. That solution, in Rhino Grasshopper form, looks like this:

Grasshopper definition

This solution allowed me to precisely control the spiral's radius and pitch (i.e. angle of ascent). These were crucial, given that I wanted the bottom of the spiral to blend gracefully into a circular base, the middle to taper inward, and the top to blossom outward.

The spiral complete, I turned my attention to the pot itself. The lip echoes the shape of the spiral holding it up. The pot's bottom is a bit cheeky, in that it's too narrow to stand on its own. Only the symbiosis of vessel and vessel-holder makes this pot work.