Since some time now, it is becoming more and more common to see lathes where two turrets perform machining operations simultaneously.
This type of machines can double their productivity by cutting machining time in half. The big drawback is programming the part managing the job of the two turrets separately. The user must bear in mind the positions of both tools at all times in order to prevent a collision between both turrets. The collision is a risk for the integrity of the machine and avoiding it takes considerable programming time.