Sort of related: I did some work in a factory that had alot of sewing machines. When there was a problem with one, they would just un-plug it and plug in a replacement. Problem is these are three phase machines, and not all wired the same. Plant maint. department solution: plugs made up with two of the phases swapped so as to reverse rotation, machine running backwards, just plug in a reversing plug and keep on sewing.
