<p>Is there a classification of method of control most (FDM) 3D printers fall under?</p>

<p>From a 1986robotics textbook<sup>ref</sup> I was reading they defined three classes of control:</p>

<p>1) Pick and place</p>

<p>2) Point to point</p>

<p>3) Continuous path</p>

<p>However, both point to point and continuous path control are stated as requiring servo motors.</p>

<p>I know that the majority of 3D printers are actuated with stepper motors as opposed to servo. Does the continuous path classification still apply? Or is there another classification?</p>

<p>ref - <em><a href="https://www.springer.com/gp/book/9789401167703" rel="nofollow noreferrer">Todd, D.J.(Ed.):Fundamentals of Robot Technology: An Introduction to Industrial Robots, Teleoperators and Robot Vehicles - Kogan Page 1986</a></em></p>

The question is if robots classification terminology the textbook sketches applies to 3D printing?
Servos (closed loop) are used in robots to guarantee position (you don't want to accumulate an error after repetitive movement), most 3D printers use open loop steppers that are instructed on a point to point basis through G-code instructions, implying that the use of servos is not a "requirement" for point to point control.
It
is
a requirement if you want to be absolutely sure that the position is reached. In 3D printing where the loads are generally low, this requirement is frequently dropped. But, there are printers that use servo control.
Note that many CNC machines (operating at much higher loads than a 3D printer) even don't use servo's but (open loop) steppers, these are generally larger and more powerful (more torque).