Building round objects from rectangular bricks is a challenge. This makes MOCs which employ round building techniques all the more impressive.
- Just bricks: use 1 x 2 bricks (or plates) and flex them. Explained at http://www.mocpages.com/moc.php/53073.
- Hinges in a row: like http://www.flickr.com/photos/45244184@N04/6803399529/in/photostream.
- Bricks and cylinders: you can alternate a 1 x 2 (or longer) brick with a 1 x 1 round brick (or a 1 x 2 plate with a 1 x 1 round plate). For an example, see http://www.mocpages.com/moc.php/122252.
- Tank treads (John Boozer): use tank treads for a central core, attaching an outer facade to them. Explained at http://mocpages.com/moc.php/257825.
- Brackets and plates (Deb Higdon): alternately stack angle brackets and plates, leaving a slight gap each time.
- Hinges: similar to brackets and plates, but using hinges, like Nannan Z.
- Expert builder gear and ZNAP beams: by bikicsmilan
- Steering wheel used as hub, attached to circumference with your choice of clip piece. For example this Buckeyball by Bram.