we were learning about electrical motors in class the other day and my teacher mentioned linear electric motors, which from what he said are basically standard motors 'unravelled'. i was wondering why, if this is the case, you would ever use a standard motor when linear motion was required? why use a 'rotational' motor in combination with camshaft (or equivalent) to convert the rotational motion to linear? if you wanted to change from a rotational motor to a linear motor (when linear motion is required) is it as simple as simply swapping them out and changing the 'drive' shafts? thanks.