# Tobel

## Equation

$x^3z+x^2+yz^3+z^4 = 3xyz$

## Properties:

• degree 4
• unbounded
• singular an the z-axis
• singular at the origin, too!

## Some story

I really like Tobel. It's smooth flowing curves and voids attract my eye and hand. In my mind, it evokes a feeling akin to that of Eistute

To print Tobel gave me trouble, but neither for mathematical nor computational reasons. I battled for four months a persistent failure problem on one of my printers, and this was the test piece. Why did I choose Tobel? It was next in the sequence to print (thanks Foong Min Wong!) and especially beautiful to me. The persistent failure was eventually solved by running a grounding wire to the extruder motor.

input