A lot can go wrong when you're printing a 3D object, with the inconvenient "stringing" being one of the most common.

Increase your travel move speed Moving rapidly to reduce unintentional filament drips Another way to fix stringing is to speed up your printer’s nozzle when it’s not printing.

In the video after the break [dizekat] gives us a throwback to those times with the Marionette 3D printer, completely forgoing linear rails in favor of strings.