Square wheel
.jpg){kind=link}
A square wheel is a wheel that, instead of being circular, has the shape of a square.Template:Circular definition While literal square wheels exist, a more common use is as an idiom meaning stereotypically bad or naive engineering (see reinventing the wheel).
A square wheel can roll smoothly if the ground consists of evenly shaped inverted catenaries of the right size and curvature.<ref>Template:Citation</ref><ref>Template:Citation</ref><ref>Template:Citation</ref>
A different type of square-wheeled vehicle was invented in 2006 by Jason Winckler of Global Composites, Inc. in the United States. This has square wheels, linked together and offset by 22.5°, rolling on a flat surface. The prototype appears ungainly, but the inventor proposes that the system may be useful in microscopic-sized machines (MEMS).<ref>Template:Cite book</ref> In 1997 Macalester College mathematics professor Stan Wagon constructed the first prototype of a catenary tricycle. An improved model made out of modern materials was built when the original vehicle wore out in April, 2004.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
In 2012, MythBusters experimented with modifying vehicles with square tires, determining that, with speed, a truck fitted with square wheels can deliver a relatively smooth ride.<ref>Template:Citation</ref>